Reason and Experience: AS Philosophy 1

Transcription

1 Reason and Experience: AS Philosophy 1 1: Plato ( B.C.) 2: Rene Descartes ( ) 3: Gottfriend Leibniz ( ) 4: John Locke ( ) 5: George Berkeley ( ) 6: David Hume ( ) 7: Immanuel Kant ( ) 8: A. J. Ayer ( ) 9: Noam Chomsky (1928-)

2 Table of Contents Reason and Experience: AS Philosophy Table of Contents... 2 Chapter 1: Reality And Our Knowledge Of It... 5 The World Around Us... 5 Getting the world inside: concepts and ideas... 5 Getting the world inside: thoughts, beliefs and knowledge... 6 How high is the bar?... 7 The Varieties of Knowledge... 8 Epistemology... 9 Knowledge and Reality... 9 Summary Questions Chapter 2: Plato, Forms and Innateness Introduction The Allegory of the Cave Reason, Philosophy and the Forms Meno, Innateness and the Slave-Boy Intuition and Demonstration Summary Questions Chapter 3: Problems with Plato Introduction A Past Life and A Priori Knowledge Circles and Ideas Learning or recalling? Strange Forms Strange Forms: Properties and Participation (*) Summary Chapter 4: Classical Rationalism: Descartes Introduction Descartes: Scepticism about the Senses Descartes: The Cogito and Self Descartes: The Wax Descartes: God & The Ontological Argument Descartes: God & The Cosmological (Trademark) Argument (*) Summary Questions Chapter 5: Classical Rationalism: Problems with Descartes Introduction Dreaming and the Demon: Can We Resist? The Demon: Can We Resist? The Self The Wax... 34

3 Could Reason Be Faulty? Summary Questions Chapter 6: Reality and Rationalism Introduction A Priori and A Posteriori Science and Reality Leibniz, Maths and Necessity Necessity and Contingency A Priori and Necessary: The Scope of Rationalism Reason and Introspection (Inner Sense) Summary Questions Chapter 7: Classical Empiricism: Locke Introduction: From Rationalism To Empiricism Innateness Where Our Ideas Come From What We Know Knowledge and Necessity Scepticism and The Veil of Perception Summary Questions Chapter 8: Classical Empiricism: Berkeley on Locke Introduction Berkeley on Abstraction Berkeley and Idealism Summary Questions Chapter 9: Classical Empiricism: Hume Introduction Where Our Ideas Come From Hume's Fork What can we know about reality? Deduction and Induction A Priori Knowledge of Existence and Causes The Problem of Induction The External World The Internal World Big Ideas Deflated Summary Questions Chapter 10: Problems With Classical Empiricism Introduction Innateness Complex ideas Simple Ideas Scepticism... 74

4 Summary Chapter 11: Kant and Kantianism Introduction Kant s Revolution: The Rationalists Kant s Revolution: The Empiricists Scheme and Content Phenomenal and Noumenal The Analytic and the Synthetic What Experience Cannot Do: Structure and the Synthetic A Priori The Importance of the Synthetic A Priori Summary Questions Chapter 12: Problems With Kant and Kantianism Introduction Realism and Idealism Science and Experience Science and Metaphysics Mathematics and Psychologism Chapter 13: Linguistic Relativism and Conceptual Schemes Introduction Linguistic Conceptual Schemes The Sapir-Whorf Hypothesis Words and Concepts Is the Sapir-Whorf Hypothesis Just Nonsense, Then? Untranslatable Words? Common Worlds And Conceptual Schemes Summary Questions Chapter 14: From Logical Positivism to Quine Introduction The Verification Principle Knowledge and Reality Mathematical Knowledge Quine s Web Of Belief Logical Positivism: Other Concerns Official AQA Specification Module Checklist Glossary of Key Concepts Appendix I: Mathematical Proofs Proof #1: Pythagoras theorem Proof #2: Euclid's Proof (Nearly) That There Are Infinitely Many Primes Proof #3: A Proof of the Irrationality of Appendix II: PowerPoints

5 Chapter 1: Reality And Our Knowledge Of It - The World Around Us Chapter 1: Reality And Our Knowledge Of It The World Around Us The intuitive picture of the world that we all naturally develop is of a collection of things arranged in space that all move through time. There is more to it that our actual planet, of course. The whole of space is the whole of the universe whose dimensions are still unclear. Philosophers often use the world to mean the universe or all there is and we shall follow this way of talking too. The world, then, has existed since before you and I were born and will continue to exist after we are gone, even though it is sometimes hard to imagine this. It is a highly organised world. The things around us fall into kinds and have similar properties. There are, for example, six people in this room and seven chairs. There are various red things in this room a tie, a board rubber, and the cover of a book. Things behave in organised ways too. If I push the tie or board rubber or book of the desk, it will fall to earth. As time moves on, the sun will go down and it will get dark and this happens in a regular, predictable way. We can all easily talk about the ways in which the world is structured and organised. We can talk about what things are like and what they will do under various conditions. Indeed, our knowledge here outruns our powers of description. We know how to tie shoes, ride bikes, speak English, read people s faces, find our way home, and so on. We constantly show off just how much we have learned about what the world is like and how we can usefully exploit it. Getting the world inside: concepts and ideas How is all of this is possible? How is that we manage to know so much about the world? How does out there get into in here into my head? The obvious place to start is with our senses. The senses let the world into the mind. I open my eyes and suddenly I experience a complex scene of many coloured objects spread across a desk. I hear the conversions around me, smell the coffee before me and feel the keys as I type. It is tempting to think of our senses as simple windows onto the world. I simply see the world as it is. But this can t be quite right. The world doesn t make itself obvious in all respects. Two people can see the same world and yet not see the same things in the same ways. For example, imagine transporting a man alive in 20,000 B.C. into the modern world. He would see ties, coffee-cups, helicopters and iphones but not know what these things are. Our primitive man would of course see the ipod in the sense that it would cause a certain visual experience. He would have visual sensations or impressions of a shiny silver rectangle. He has no idea or concept of what an ipod is. Ideas or concepts give us our grip on the world. They enable us to think about the world. It is because I have the idea or concept of a cup that I can recognise one on my desk. I can also think about cups when they are not there. If I desire a cup of coffee or someone asks me to lend them a cup, I know what to look for and what they mean. When we are young, it seems we have few concepts which is why the world is unfamiliar and confusing. As we grow, we learn more and we understand more. It will be helpful to think of ideas and concepts as like words. To talk about things in the world, we need words for them. We don t of course simply talk about the world by listing the names of things. We organise words into sentences. A sentence paints a picture of the world and is true or false depending on whether the picture is accurate. Similarly, we don t think about the world by having concepts of things pass through our mind. We form concepts into thoughts that are likewise representations of reality. So, just as I can say, my cup is on my desk, I can think my cup is on my desk. I cannot think that thought without the concepts cup and desk. Page 5/109

6 Chapter 1: Reality And Our Knowledge Of It - Getting the world inside: thoughts, beliefs and knowledge In the same way, we talk about perceiving that something is the case. The primitive man can see the ipod but cannot see that it is an ipod. When we use the see-that form, we attribute someone a conceptualised understanding. When we simply use the see form, we merely mean it registers in their visual field as some sensation or complex of sensations. Although we use idea and concept interchangeably, we ll note now that they have been used differently. It will matter for this course. For some, an idea is essentially sensory. So, an idea of a bottle is like a picture of a bottle in the mind, for example, and an idea of a trumpet might be (or partially be) a sound of one. A concept does not carry that implication. I have a concepts of gravity and algebra but I don t see or hear anything when I think about them. Another important word to add here is proposition. The sentences It is raining, Il pleut, Esregnet and Pada deszcz all mean the same thing: it is raining. They all paint the world to be a certain way. This way is the proposition. When Kate thinks the thought it is raining and when Kasia thinks the thought pada deszcz, they are thinking the same thing too. We can say that they are thinking the same thought or the same proposition. 1 Getting the world inside: thoughts, beliefs and knowledge A thought is like a sentence a representation of the world. It is not a representation in the way a picture is. A picture looks like the world whereas a sentence is a stream of sounds or symbols. But this just shows us that not all representation is resemblance. If I think about things, I run thoughts through my head. If I believe something, then I think something to be true. I currently believe that it is Tuesday, for example. My thought is in italics. In fact, I can go further: I know that it is Tuesday. It s better to know than to believe. When we investigate the world around us, we want to gain knowledge. Our central question is: how is it possible to have knowledge of the world? So why is knowledge what we want to focus on? As we have just seen, when we say I know that so and so is the case and in so doing we seem to be recording how the world is. But we do something arguably similar with other verbs: I know that it is raining I believe that it is raining. I think that it is raining. I reckon that it is raining. There certainly seems to be a difference between (merely) believing that something is the case and knowing that something is the case; and the same goes for the other verbs. Knowledge is in some way special. In what ways? Let us say that there has never been a visit to our planet by an intelligent extra-terrestrial life form. Anne may be convinced that she has been the victim of an alien abduction. In fact she was kidnapped by a team of X-Files enthusiasts who carried out a series of experiments on her. Now, while Anne has a sincere belief that aliens have visited, this belief turns out to be a false one. While we understand why she possesses the belief, we cannot say she knows. Why not? Because if you know, what you know is true. We say that knowledge is factive. For a second comparison, consider the belief people have had that the sun orbits the earth. It is true to say that people said they know, that they thought they knew but we cannot say they did know. So, we can say that whereas you can believe something that is false, you cannot know something that is false. Page 6/109

7 Chapter 1: Reality And Our Knowledge Of It - How high is the bar? Now for a second reason. Suppose you ask Bill and Bob the time. Bill says, I believe it is Bob says, I know it is Whom do you trust? You trust Bob. Why? Because if you say that you know, you are more confident than if you believe. What gives you the confidence? Evidence or justification. If you know, you claim to be able to back up what you say. By contrast, you can believe something and be honest that your evidence is pretty slight. We can talk of degrees of belief or certainty or justification ranging from 0 to 100%. If you believe with 100% certainty, you are so confident you will say that you know. Your evidence (you think) is that good. So, I believe with 100% certainty that it is raining as I can see rain through the window. I believe with 90% certainty that it will be raining in twenty minutes. The rain looks heavy now but I am no expert and I can t rule out that it will come to an end in fifteen minutes. Still, I am more certain it will be raining than it won t be. I am 50% certain that it will be raining on this day here in That is, I am no more certain it will than it won t. This is perfectly sensible as it is utterly unpredictable. You can think of degrees of knowledge in terms of making bets. The more you are prepared to bet on the truth of something, the closer you are to 100% confident of it. So, we can say that when you know something, you have a high degree of justification whereas you can believe something with a lower degree of justification. We have arrived at the earliest and most influential answer to the question of how we should distinguish belief from knowledge, due to Plato. To distinguish mere opinion or belief from knowledge Plato, suggests that we define knowledge as true belief with a logos (an account). 2 This notion of an account has been understood and developed in terms of the justification for holding the belief. We are concerned with knowledge because we want and value true beliefs. The pursuit of knowledge is the search for the kind of justifications which underwrite the beliefs we possess. The definition of knowledge with which we shall begin has been called the tripartite definition or account of knowledge because it decomposes what we mean by knowledge into three elements. Where p stands for a proposition: S knows that p if and only if: o S believes that p. o p is true. o S s belief that p is justified. How high is the bar? We are ordinarily more confident of the truth of some of our beliefs than others. I know it is Tuesday and I know that 2+2=4. I strongly believe that it will not be 30 0 in Twickenham tomorrow but I m not as sure. Do I know? Some philosophers have reasoned in the following way. If you know, you can t be wrong. For you can know what s true. If you can t be wrong, then there can be no room for doubt. So, the bar must be set as high as possible. If you know, you must be certain. If you are certain that it is Tuesday, there is no way you can be wrong. All sources of doubt have been eliminated. An obvious problem with this is that it threatens to reduce our knowledge to nothing. I have said I know that it is Tuesday. But could I be wrong? Well, conceivably. It could be Wednesday and I could be the victim of a hugely-expensive practical joke. I went to sleep on Monday and was sedated until Wednesday. All the papers have been printed to say it is Wednesday. Everyone around me has been bribed to say it is Wednesday. I would be like the man in the film The Truman Show, who is unaware that he is effectively an actor in a play. Unlikely? Yes. Impossible? No. Or, to push it to a well-known extreme, all that I take to be the world around me could be nothing more than a computer-generated world, such as in the Matrix. Page 7/109

8 Chapter 1: Reality And Our Knowledge Of It - The Varieties of Knowledge If we had to try to rule out all conceivable sources of doubt, then perhaps we could know nothing. Some argue that this unhappy situation is actual. Such philosophers are sceptics. To be sceptical is to doubt. A sceptic in philosophy doubts that knowledge is possible because we cannot ever jump over the bar of certainty. We cannot rule out all the sceptical possibilities such as Truman-style pretend-lives or Matrixillusions. We shall not be looking specifically at the issue of scepticism but we shall keep it in mind. For we will see that philosophers who have sought knowledge have sought to raise the bar as high as possible to avoid the threat of scepticism. Henceforth, unless we say otherwise, our philosophers will set the bar as high as possible. They will demand certainty. Now, it is important to observe that certain is a slippery word: I m certain he s not at home. I feel as confident as I can be. But you can feel confident and be wrong. We don t want this psychological meaning of certain. It is certain that 2+2=4. There is enough evidence to rule out any possibility of this being wrong. This is the epistemological sense we re after. Philosophers want the truth. Not being God-like, they cannot simply see the truth. They must therefore gather evidence. Aware of their fallibility, they make the project as hard as possible. They only recognise those truths that somehow present themselves as true in a way we can t doubt. Such is how many philosophers approach their inquiries. The Varieties of Knowledge So far, we have considered knowledge-that or propositional knowledge: I know that o it is sunny. o Paris is the capital of France. There are other kinds of knowledge. There is knowledge-how or ability knowledge: I know how o to swim. o to drive. And there is knowledge by acquaintance : I know o Bob o Paris The ordinary notion of knowledge includes the possession of a skill, being acquainted with something and having knowledge of facts. The relationship between these kinds of knowledge is an interesting topic. However, it is knowledge of facts or propositional knowledge that has been the central concern of epistemology. The term propositional knowledge simply refers to the fact that our knowledge claims are claims about propositions. As we have seen, a proposition is what is asserted by a sentence which says that something is the case for example, that Leeds Utd. has had a great start to the season, that bachelors are unmarried men, that the Earth is flat. Sometimes what we claim is true and sometimes it is false. Proposition are expressed in sentences that are capable of truth or falsity. The clause following that in the sentence I know that. is what one claims to know. In that clause we are stating what we take to be the fact of the matter. Page 8/109

9 Chapter 1: Reality And Our Knowledge Of It - Epistemology Epistemology We have spent this introductory chapter discussing epistemological matters. Epistemology is the branch of philosophy that deals with knowledge and related issues: What knowledge is. Whether it is possible. How it is possible (if it is indeed possible). What sorts of knowledge there are. Where knowledge comes from. The word is from the Greek, episteme, meaning knowledge and logos, meaning theory. It is an essential branch of philosophy and illustrates what sort of thing philosophy is. Art historians, biologists and economists are all searching for knowledge but they do not stop to think about what knowledge is. In some sense, they take it for granted that we all know what knowledge is and that there is knowledge to be had. That more basic question falls to the philosopher. Philosophy concerns itself with the fundamental questions. It investigates the concepts that are at once extremely familiar and deeply puzzling. You have said that you know something a great number of times in your life already without stopping to wonder exactly what you are saying. When you start to look, you can quickly find yourself led to the sceptical conclusion that there is no knowledge after all! We should note from the outset that the issues above are not matters philosophers consider purely for the love of speculation. Our very understanding of the world, ourselves, and the relationship between ourselves as subjects of knowledge and experience and the world, may ultimately depend on the answers we have to questions concerning the nature and sources of knowledge. On the face of things when one knows that such and such is the case one is in a special kind of position. To know something is to be getting things right in the sense that you ve grasped the fact or truth in question. Furthermore, knowledge appears to be valuable. It is the goal of enquiry. I do not just want to possess beliefs, but seek knowledge. Our understanding of the world is dependent on knowledge as are our judgements of what we ought to do. Knowledge and Reality The question that will concern us is: how is knowledge of reality possible? How are we able to say what exists? (Are there cats? minds? atoms?) what the natures of these things are? (What makes cats cats? What makes a beautiful thing beautiful?) what happens or occurs (What are the laws of nature? How does cause lead to effect?) In the next few chapters, we shall look at a philosophical movement called Rationalism. It says the following. Common-sense says we experience reality through our senses. Yet our senses do not give us our ideas or knowledge. Our senses present reality in a confused way. We gain knowledge through the use of reason. Our faculty of reason is a special truth-detecting faculty that transcends our senses. It enables us to see reality clearly: what exists and what it is like. Knowledge begins with intuitions direct grasps of truths. This is made possible by our having innate ideas and innate knowledge of reality: we are born with it. We then demonstrate or deduce further truths. Our knowledge of reality thus is grounded in reason rather than experience and is called a priori knowledge. We will then turn to a rival view, Empiricism. It says: Page 9/109

10 Chapter 1: Reality And Our Knowledge Of It - Summary All our knowledge of what exists in reality and what it is like must be grounded in sensory experience. We do not have a special truth-finding faculty or reason or any innate ideas or knowledge. We are born as blank slates with merely the ability to process sensory data into ideas or concepts in accordance with simple rules, such as composition and association. Our knowledge begins with basic sensations whose existence and nature we are certain of: that I seem to see a red circle, perhaps. My immediate awareness of them is like the Rationalists intuitions of the truth. From there, we can compose more complex ideas and thoughts. Our knowledge of reality is a posteriori knowledge. All our a priori knowledge is merely of relations between ideas or concepts or of analytic truths. We shall then turn to a third view, that says we need to mix the two. It was developed by the philosopher Kant and is called Kantianism. We are not born with any innate knowledge or ideas of reality. The only reality we can know is the one we experience. We do not however gain all our concepts simply from experience as the Empiricists would say. We have special a priori concepts that organise the raw data of experience so that coherent experience is possible. These concepts are not concepts of a reality beyond experience as the Rationalists would say. It is senseless even to think of a reality beyond experience. We can only know reality as it is structured by our minds. Our experience must be structured the way it is for otherwise experience would be impossible. Our way of knowing reality is therefore the only one possible. We shall also look at what happened after Kantianism in the 20 th century but you should focus on the three positions above as the centre of the course. You should also bear in mind that we will be both leaving out and simplifying many of the details. The more that you learn about the philosophers who are labelled Rationalists and Empiricists, the more you will see that there are significant differences between them. Summary Ideas or concepts that are the ingredients of thoughts and thoughts are the way we represent reality or the world out there in our minds. We want knowledge of the world, where to know is to have a justified true belief. Justification and confidence come in degrees, with certainty at the top. If I am certain of something, then there are no grounds for doubt and so what I am certain of is true. Scepticism is the view that the bar for knowledge cannot be reached. These are issues with epistemology, the branch of philosophy dealing with knowledge. Our central question is: how is knowledge possible? Questions 1) Think of some of the concepts you understand just think of words you are familiar with, such as shoe, cloud, potato, and so on. How would you explain how you have come to have them? 2) Do you think we are born with any concepts? Or born knowing anything? 3) Think of some things that you know. How do you know them? What s your justification what would you say to convince someone? 4) I know it but I don t believe it! Since to know is to believe, this is surely nonsense. Is it? Page 10/109

11 Chapter 1: Reality And Our Knowledge Of It - Questions 5) Can you believe something if you think it is more likely to be false than true? 6) Is there anything you are certain of? 1 We use the words thought, concept and idea in an ambiguous way in English. If Kate and Kasia are both thinking it is raining, then there are two thoughts if we mean things in the head and one thought if we mean one thing outside the head. Similarly, I can talk of Kasia s concept (something in her head) of rain and the concept of rain (outside of the head) that my friend s daughter doesn t yet understand. We can say that propositions are composed of concepts like sentences are composed of words. We can say, in one sense, a proposition is a thought a thing outside the head that represents the world to be a certain way. Or we can say that a thought is a proposition encoded in the head by concepts that are likewise in there. 2 Plato explores the question what is knowledge? especially in his two dialogues Theaetetus and Meno. In Meno, Plato famously says that the difference between knowledge and right opinion or true belief is that knowledge is tethered. When we know, we have something stable. This is because it is justified. We may have a true belief but we can be right by luck. Even if I felt certain that I would guess this week s lottery numbers and did guess them correctly, I still couldn t have been said to have known them as I was still lucky. Page 11/109

12 Chapter 2: Plato, Forms and Innateness - Introduction Chapter 2: Plato, Forms and Innateness Introduction How is knowledge possible? This is a question that fascinated the earliest philosophers in Ancient Greece. The first philosopher to investigate what knowledge is was Plato. Plato was the pupil of Socrates, perhaps the most famous of all of philosophers. We know Socrates through Plato s books or dialogues as they are known, as they are written in the form of conversations. Plato himself never appears in his own dialogues, which has led philosophers ever since to wonder whether, when Socrates speaks Plato s words, they are Socrates own thoughts written down or Plato s thoughts put into Socrates mouth. For our purposes, it doesn t matter. We shall talk of Socrates and Plato as effectively the same person. Common-sense tells us that we learn about the world through the senses. We start off, as babies, as empty. We have sensory experiences: we experience colours, smells, tastes and so forth which we may call impressions or sensations. These sensory experiences of the world give us our concepts and knowledge. The world is largely as it seems and our senses simply transmit its qualities to us. The apple before me, for example, is a spherical bit of stuff that is green, smooth and sweet. The Ancient Greeks of the 7 th -5 th centuries B.C. started to think that common sense might not be right. They started to think of a distinction between how the world appears and how the world really is. At the heart of their thinking was the following problem. On the one hand, we see a world of diversity and change. There are many people in this room at the moment, each one differing in ever so many ways from the others: from different heights through different tastes in music to different places of birth. Furthermore, each of them and everything else is constantly changing. I change my location, the position of my limbs, the thoughts in my head and of course all the cells in my body are constantly changing too. On the other hand, there must surely be stability. The people in the room may all differ but they are all of the same kind: people. And though I may change in ever so many ways, there is still the same me over time. Or so, it seems. Some philosophers, such as Heraclitus, said no: change is the nature of reality. Others such as Parmenides said yes: reality is fixed and unchanging and all change is illusion. Plato was in the middle. There are two worlds: the world of changing appearances and the world of stable reality. Our senses tell us about the former. Our special faculty of reason tells us about the latter. Although he lived long before the 17 th century, which is the century in which Rationalism flourished in its modern form, Plato can be considered a rationalist. In this chapter, we consider some of Plato s reasons for saying that only reason can give us knowledge of reality. The Allegory of the Cave Plato explained what he meant with a famous image, that of the cave. In the picture below, you can see prisoners chained so as to face the cave wall, on which they see shapes. The shapes are cast by thing outside the cave. The people naturally think that the things they see are real. After all, that s all they ve ever seen. But that s a mistake. They see mere shadows of reality. Reality exists outside the cave. Only by breaking free of their chains can they discover it. This will take much work. Once they are outside, the light will be bright and the real world dazzling and unfamiliar. It will take time to get used to it. The ordinary person is like a prisoner. He naturally thinks that what he sees is real. But he sees mere appearances. This does not mean that he is cut off from reality. Just as shadows are produced by real things, so too are appearances. We might say that the ordinary person sees reality in a confused way. It is only by doing philosophy that one can break free and learn what reality is really like. Page 12/109

13 Chapter 2: Plato, Forms and Innateness - Reason, Philosophy and the Forms What will we discover? What is reality made up of and how do we get to know about it? Reason, Philosophy and the Forms Plato s answer was that reality is made up of the forms and that we discover the forms through the use of reason. In this section, we will summarise Plato s views and in subsequent sections, we will look at the details. We have various senses that present the world to us in the languages of colours, sounds, tastes, smells and feels. In this respect, we are like many other living things. We also have a faculty of reason that many philosophers have identified as the thing that makes us distinctly human. Reason is what we use to understand the world. It is through reason that we can grasp concepts and think thoughts. Now, ordinarily, we simply think thoughts in the same way that we speak words. We do it without thinking about it. But we can use reason to examine what we are doing. We can use the eye of reason to examine a concept just as we can use an actual eye to study the structure of a flower. Instead of merely thinking the thought that there is cat in the garden, we can focus on the concept cat and ask: just what is a cat? When we stop to examine concepts like this, we are doing philosophy in its broadest sense. We are asking about the way things are. Our senses tell us when there are cats about. They do not tell us what cats are. No two cats look exactly the same. There is no obvious feature we can see that is distinctly cattish. Cats can be big or small, tabby or black or white. Most cats have tails but Manx cats do not. A cat that loses a leg or its whiskers is still a cat. What makes cats cats is not obvious. We need to think about it. What we will discover, says Plato, is that there is something that the many different cats have in common that makes them cats and that this is the form of the cat. It is what we grasp when we have the concept or idea of a cat. By exploring our concept, we can gain knowledge of what cats are like. It is the real thing that we see confusedly in all the different cats. It is not something that we can really see as it is not a sensible thing. It is not part of the ordinary, familiar world that is revealed to us by the senses. It exists in another realm entirely. The most distant star is visible to me because the light hits my eyes. How does a form, if not part of this world, get into my mind, if not through my senses? Plato s answer was that we are born with knowledge Page 13/109

14 Chapter 2: Plato, Forms and Innateness - Reason, Philosophy and the Forms of the forms. We have innate ideas or in-built concepts. His explanation for this was that our souls existed before us in the realm of the forms where they learned about them. Here on Earth, where we are reliant on our senses and trapped in the body, our knowledge is not lost but buried. When we do philosophy, we are really just trying to dig out the concepts already in our minds to examine them more fully. So, Plato s answer to our central question runs like this: How do we know what we know? We are born with innate ideas. We know them confusedly because we can identify cats as cats without knowing exactly why they are cats. By digging doing philosophy we can bring them before the mind s eye and gain an ever more complete knowledge of reality. Let s now turn to some details. We want to ask the following: Why believe in the forms? What do they do? Why are they so strange? Why believe we are born with ideas? The Imperfection Argument Below is a circle. It is a good, but not perfect circle. If you magnify it enough times, you can see that it is fuzzy and jagged. The same will be true of any circle you draw, no matter how good your screen, printer or hand. The same will be true if you cut a circle out of (e.g.) a sheet of steel. Furthermore, a circle is a two-dimension shape. In a three-dimensional spatial world, any circle is really a cylinder. 1 A perfect circle cannot be seen or touched. Yet we all know about perfect circles. We know, for example, that the area A of a circle with radius r is πr 2. We know that the circumference is 2πr. We may prove and explain this with handdrawn circles but we recognise circles as imperfect copies of the real thing that we could ultimately do without. We have the idea of a circle even though we have never and can never see one. We can therefore conclude: that there must be such a thing as a (perfect) circle that is not something that can be discovered with the senses and so only by reason. It is the form of the circle. that our knowledge of the circle our concept of it can t have been gained through experience. In short, we can only explain how we see make sense of imperfect copies by giving ourselves knowledge of perfect things they are copies of: the forms. The Knowledge Argument Like many philosophers to follow, Plato drew a sharp distinction between what we know and what we believe. Knowledge is important and belief is at best useful. The reason is that knowledge is infallible and belief fallible. If I know that p, then p must be true. There is no room for error. But I may believe that p and it may turn out false. Knowledge is worth having because there s no room for doubt. Now, what can I have knowledge of? The objects of my knowledge can t be things that are able to change. For example, it is sunny now but it might not be later. I can therefore believe that it is sunny but Page 14/109

15 Chapter 2: Plato, Forms and Innateness - Reason, Philosophy and the Forms not know it. The changing weather is not something fit for being known about. The same goes for anything else in the familiar changing world that the senses reveal to us. We certainly do have knowledge. I know that a square has four sides, for example. So, there really must be things to be known. These things are the forms. The form of the square is an unchanging thing. It will always be true that a square has four sides, for example. That simply cannot change. We can put all this together as a step-by-step argument: 1) Knowledge is possible. (There s lots we can and do know.) 2) Knowledge is infallible. (If you know, it you can t be wrong.) 3) Knowledge must be unchanging things. (If it can change, it could turn out to be false later.) 4) Unchanging things aren t the ordinary things in the world of appearances that the senses reveal. 5) So, unchanging things must be elsewhere. These things Plato calls the forms. The One-over-Many Argument There are many cats in the world and there are many more things that are not cats. What makes cats cats is that they have something in common. Without something in common, there would be no such thing as being of the same kind. Similarly, there could be no properties. My shirt and my eyes are both blue. The property of being blue is something they have in common. So, to explain how different things are the same and how we know they are, there need to be things that make different things the same that our minds can grasp. These things are the forms. Once again, they are not things we can sense. Cats do not simply look alike. We can t simply say that cats have four legs and whiskers: cats can lack these things. For a clearer example, consider beauty and good. A picture, a sunset and a piece of music can all be beautiful but appear utterly different. Returning a lost phone, helping someone in their hour of need and giving to charity can all be considered good but again appear utterly different. Furthermore, in the world of appearances things change and die. But whereas cats could become extinct and all the beautiful things could be destroyed, cattiness and beauty itself cannot be destroyed. It would then become impossible even to think or speak about cats and beauty. This observation links with the one above: the forms must be unchanging (as what it is to be a cat can t change) and indestructible (as only things can perish). Bringing the Forms Together The forms do a lot of work for Plato. They give structure to the world: they explain properties and kinds. They enable knowledge by being unchanging. They are what we grasp with concepts and ideas that enable us to think and talk. Page 15/109

16 Chapter 2: Plato, Forms and Innateness - Meno, Innateness and the Slave-Boy The search for the unchanging is the search for the natures or the essences of things. It is useful to know where my cat is but it is not philosophically very interesting. What is interesting is to know what it is to be a cat. All philosophy and science is a matter of asking this sort of question, thought Plato. What is space? What is beauty? The knowledge we seek is of the timeless way things are. Later, we shall say that the knowledge that matters is knowledge of necessary truths: truths that must be true, like 2+2=4 as opposed to truths that happen to be true, like Paris is the capital of France. Meno, Innateness and the Slave-Boy How do ideas get into our heads? According to Plato, before we were born, our souls existed and lived in the reality where the perfect circle is to be found. Some time after conception, our souls enter the material world and our bodies. They carry with them the knowledge of what is in the realm of the forms. So, we are born with innate ideas and innate knowledge: innate means in-born. We can identify ideas and concepts when thinking about Plato. So, the claim is that I am born with the concept circle. It is my mental copy of the form. What I know in virtue of this about circles counts as innate knowledge. How did Plato establish such a surprising claim? Consider the dialogue between Meno and Socrates in the dialogue Meno. Meno s slave-boy has received no education yet is capable of doing maths, says Socrates. He draws a square in the dust. 2 and asks the boy how to construct a square with twice the area. Simply doubling the sides will give a square with four times the area, as the slave-boy realises after suggesting it: By asking the right questions, Socrates gets the boy to realise that you need to build a square from the diagonal of the original square: The following exchange then takes place: Page 16/109

17 Chapter 2: Plato, Forms and Innateness - Intuition and Demonstration Socrates: What do you think, Meno? Has he, in his answers, expressed any opinion that was not his own? Meno: No, they were all his own. Socrates: And yet, as we said a short time ago, he did not know? Meno: That is true. Socrates: So these opinions were in him, were they not? Meno: Yes. Socrates: So the man who does not know has within himself true opinions about the things that he does not know? Meno: So it appears. Socrates: These opinions have now just been stirred up like a dream, but if he were repeatedly asked these same questions in various ways, you know that his knowledge about these things would be as accurate as anyone's. Meno: It is likely. Socrates: And he will know it without having been taught, but only questioned, and find the knowledge within himself? Meno: Yes. Socrates: And is not finding knowledge within oneself recollection? Socrates concludes that the boy has not had new knowledge put into him by Socrates. He has merely discovered what was in his head all along. He has recollected it, as Socrates puts it: recalled it from his past life in the realm of the forms. This process of recollection is called anamnesis. So, Plato explains how we have knowledge of the forms knowledge that can t be explained via sensory experience in terms of recalling what we learned in our past lives. Our memories here consist of our innate ideas and innate knowledge. Intuition and Demonstration The Greeks held up geometry as a perfect example of what we can know. In c. 300 B.C., Euclid wrote a book of geometry called Elements that was still in use in schools at the turn of the 20 th century. Euclid started by identifying simple and clear basic ideas such as line and simple self-evident truths such as the whole is greater than the part. A self-evident truth is called an axiom. Axioms are like the foundations of a building: they need no support. From these truths we can demonstrate or deduce or prove new truths or theorems, such as Pythagoras theorem. Theorems are like the upper floors. The higher you go, the more support you need from below. But so long as each floor is solidly built on the one below, safety certainty is guaranteed. 3 What fascinated philosophers then and since is not so much the geometry but the model. You start with absolute certainties and carefully draw out further truths that are thereby certain too. All knowledge should be developed on this model: identify solid foundations and build up slowly. Rationalists like Descartes, Spinoza and Leibniz were particularly fond of this approach. In having an intuition, we have a direct or immediate grasp of the truth. We don t prove the truth from other truths: we simply see with the mind s eye of reason that it is true. Such truths are like axioms. Plato explained this ability as our mental faculty of reason as the ability to recollect what we have learned by discovering innate ideas in our mind. We then demonstrate new truths. These are our theorems. In one sense, all the truths are innate in our mind. They are not, as it were, written down as sentences in our mind that we merely need to search for. It is rather that all the ingredients are innate and all we need to do is appreciate by reason ever more complex connections between them. (Note that intuitions are not like instincts. Many instincts are hard-wired behaviours, such as our instinctual sense of balance. We may also have instincts to think or feel certain things. We might instinctively feel fear when alone in the dark. A behaviour and a feeling isn t something that can be true or false. We might instinctively think that creatures with eyes are alive in a way that rocks are not. Now, Page 17/109

18 Chapter 2: Plato, Forms and Innateness - Summary this might be true but it is still not what we mean by an intuition. An intuition isn t simply something we accept unquestioningly as true but something that strikes us as certain. We must have a sense of it having to be so.) So, when Socrates says that the knowledge was in there all along, he doesn t think that the boy is recollecting exactly that proof, as if it were the subject of a lesson in a previous life. He is recalling ideas and bits of knowledge enabling him to demonstrate or deduce the conclusion. But doesn t the boy really learn by looking at the square by using his senses? Plato would accept that we sometimes need to use diagrams to help us recollect. But they are merely aids. In the same way, we sometimes need to use a telescope to see what is far away but the telescope is inessential. In principle, we could simply move to get closer up. Summary Plato invites us to consider the familiar world of material things as a world of difference change behind which is the real world, where things are timeless and changeless. The real world contains the forms which are the objects of knowledge and responsible for the structure of the world. They must exist for how else would we explain o knowledge what we know must be changeless for knowledge to be infallible. o our grasp of the insensible, such as circles. o the sameness of things. Our concepts or ideas of the forms are innate: the legacy of our souls existences in the realm of the forms before our birth. The answer to our question how is knowledge possible? is then because we are born with ideas of the forms reflection on which leads to an ever greater understanding of reality. Plato s rationalism is clear: reason, not experience, tells us what exists (the forms) and what they are like. Questions 1) Plato argued that there is a form of the circle by considering how we can t sense perfect circles. He had a very similar argument to show that there must be a form of equality that we can t sense. Instead of asking us to consider a drawing of a circle, he asked us to consider finding two sticks of equal length. How did he proceed from here? 2) Could I create a perfect circle by shining a light through a filter onto a wall? 3) Something in her smile told me she was lying. If I say that, do I really mean that there was an actual thing in her smile? Surely not! It s just a way of talking. Could I therefore not say that there s no thing cats have in common there are just lots of cats that are similar to one another. What problems are there with saying that a cat is a cat because it is similar to other cats? 4) In Plato s dialogues, Socrates would take a concept such as beauty and ask people to define it. He would criticise their suggestions by pointing out counter-examples. So, someone might suggest beautiful things make us happy to which Socrates might reply that a good meal might make us happy but not be beautiful. Consider and criticise the following definitions and try to do better: o o o o o Bravery: a brave man is one who acts without caring about the dangers involved. Goodness: a good act is one that makes the greatest number of people happy. Animal: an animal is a living thing that can move. Game: a game is something two or more people play according to agreed rules with the aim of winning. Number: a number is something we use to represent a collection of things we can count. Page 18/109

19 Chapter 2: Plato, Forms and Innateness - Questions 1 In a two-dimensional world, a cut-out would not be a circle but a perfect circular disc. A circle is a curved line a disc is the enclosed circular area. 2 Diagrams/text taken from 3 See Appendix 1 for some examples of proofs. Page 19/109

20 Chapter 3: Problems with Plato - Introduction Chapter 3: Problems with Plato Introduction In this chapter, we ll think of some problems with Plato s picture. Here s a summary: It relies on the idea that we have innate ideas from a past life. The perfect circle is not a thing but merely an idea. Socrates was teaching the slave-boy. The forms are strange. A Past Life and A Priori Knowledge Plato s explanation of the source of ideas strikes us today as simply bizarre. Few people believe in reincarnation; and those that do don t have Plato s world of the forms as where we once resided. So, one might dismiss Plato s whole view on these grounds alone. It s important to see Plato as wrestling with a real problem, though. Plato was trying to explain how we can have knowledge of things that we can t explain through reason. As we shall see, many philosophers think that there is such knowledge and so face the same problem. Mathematics and geometry provide the favourite examples. Not only do we seem to know truths about non-sensory things but these truths are necessary truths: truths that must be true. How do we know about must be true from the limited experiences we have. We shall shortly call knowledge based on reason not experience a priori knowledge. One of the key questions we will be asking is how is a priori knowledge possible? as it is a seemingly important source of knowledge. Plato s answer is that we are born knowing the basics thanks to a past life. In the 17 th century, Rationalist philosophers like Descartes and Leibniz will say essentially the same thing: we have innate ideas put there by God. The Empiricists will try to reduce a priori knowledge to knowledge of mere truths of definition or analytic or tautologous truths. Knowing that 2+2=4 is a bit like knowing a square has four sides: it is true by definition. Some will go so far as to deny that there is any such knowledge at all. We shall revisit these points in more detail as we go forward. Let us now turn to examining the suggestive idea that maths and geometry are all about ideas, not things. Circles and Ideas What is a circle? It is not a physical thing, as Plato rightly said. But does that it mean it is a non-physical thing? It is worth being aware of a common trap in philosophy: the mistake of thinking that because we use a noun to name it, there s a thing to name. Consider the following sentences: Jim s car has a dent in it. The cat is sitting in Anna s lap. Bernard has a demanding job. There are no such things as dents, laps and jobs. They are not like cups or bricks or badgers that take up space and can be moved around. The word lap is a noun like cup but that s where it ends. You can often Page 20/109

21 Chapter 3: Problems with Plato - Learning or recalling? spot such words because they don t translate easily into other languages. There is no word for lap, for example in French or Polish. You have to say that the cat sat on Anna s knees. So, why don t we say that the perfect circle is just an idea in my mind? It is something we simply imagine. There is no strange form of the circle and no need to think of having studied it in some strange past life. Unfortunately, it isn t as easy as that. First of all, we cannot literally imagine a circle paint a mental picture of it. My image is just as likely to be a bit hazy as a drawing. If you have excellent powers of imagination, then perhaps you can picture a circle. But then consider a chiliagon: a thousand-sided figure. No-one can imagine such a thing. The obvious response is to say that we have an idea of a circle not as a mental picture but as well, something else that represents a circle. We have a mathematical idea of it as a set of points equidistant from a single point. But this merely leads us to the big problem: Frege s problem. Frege was a 19 th century philosopher who was attacking Kant s thought that numbers and shapes are also concepts in the mind. Frege pointed out that if a circle is just an idea, then there is nothing to stop you and me from having different ideas of circles. Now, you and I might have different ideas of what foods are tasty. But we can t have different ideas of what a circle is. A circle is something as objective as a cat. If someone says that his concept of a cat is of something that has four legs and goes woof, then we do not simply say that that is fine. It is not up to me to decide what a cat is. It is up to the world to determine what cats are. We then try to discover what they are like. Exactly the same is true in geometry and mathematics, said Frege. We investigate shapes and numbers. We do not invent them. So, the circle cannot be a subjective creature of the mind like an idea. Learning or recalling? Is Socrates really drawing out innate knowledge? Or teaching the boy with cleverly-worded questions? It is worth reflecting on your own educational experiences. It seems clear that plenty of what we learn is the mere storing of facts. I know that Henry VIII had six wives because I was told it and told to memorise it long ago. But you may find that there have been occasions where you have learned something because you have been made to think about it yourself. This is often the case in maths. You learn by seeing it for yourself. For example, can you prove that there is no largest number? I expect you can. You simply think of a number, n, then point out that n+1 is bigger; and since you can repeat the trick, there is no largest number. Now, when people first realise this, it is a case of realisation. It is not like memorising a fact. It is also worth observing that to put information in requires there to be something capable for receiving it. I can t teach someone about fractions unless they already understand the basic integers. I can t teach someone anything unless they understand the language I speak. Now, if someone s head were completely empty, there would be no way to make sense of the information I am trying to put in. So, it seems that there must be something in-born if we are to get started on the process of gaining knowledge. As we shall see, this line of reasoning has been appealed to by rationalist philosophers of one sort of another over the ages. Their opponents have said that we merely have the abilities to form ideas when experience feeds us the data. We don t have anything actually in our heads at birth. Strange Forms The forms have the job of uniting kinds and properties. Badgers are all badgers because they have the form of the badger. Beautiful things are beautiful because they have the form of beauty. Page 21/109

22 Chapter 3: Problems with Plato - Strange Forms: Properties and Participation (*) The first question we might ask is: does everything have a form? I can see two people in the room? What about two puddles of mud by the river? Is there a form of mud? In his dialogue Parmenides, Socrates is questioned on this: Parmenides: Socrates I admire the bent of your mind towards philosophy; tell me now, was this your own distinction between ideas in themselves [the forms] and the things which partake of them [ordinary things]? and do you think that there is an idea of likeness apart from the likeness which we possess, and of the one and many, and of the other things which Zeno mentioned? Socrates: I think that there are such ideas [forms]. Parmenides: And would you also make absolute ideas [forms] of the just and the beautiful and the good, and of all that class? Socrates: Yes, he said, I should. Parmenides: And would you make an idea [form] of man apart from us and from all other human creatures, or of fire and water? Socrates: I am often undecided, Parmenides, as to whether I ought to include them or not. Parmenides: And would you feel equally undecided, Socrates, about things of which the mention may provoke a smile?-i mean such things as hair, mud, dirt, or anything else which is vile and paltry; would you suppose that each of these has an idea distinct from the actual objects with which we come into contact, or not? Socrates: Certainly not; visible things like these are such as they appear to us, and I am afraid that there would be an absurdity in assuming any idea of them, although I sometimes get disturbed, and begin to think that there is nothing without an idea; but then again, when I have taken up this position, I run away, because I am afraid that I may fall into a bottomless pit of nonsense, and perish; and so I return to the ideas of which I was just now speaking, and occupy myself with them. So, Socrates believes in the form of the beautiful, is unsure about the form of man and rejects forms for mud and hair. But then how are we to decide what has a form and what doesn t? And if all the instances of hair can be grouped together without a form, why not everything? Strange Forms: Properties and Participation (*) If a form is in a non-material reality and we exist in a completely distinct material reality, then how do the two interact? You might be wondering: why should they interact at all? Well, consider the beautiful painting and the beautiful statue. We recognise them as beautiful. So, we recognise something in them. What makes them both beautiful is not their appearance, as we know. For they look radically different. It is the form Beauty that makes them beautiful. So they must interact. But now a problem. If Beauty is what makes them beautiful and it is in them making them beautiful, then the form is not upstairs in the realm of the forms but downstairs in the material world after all! According to Plato, the form is upstairs. But then how does the form do its work? Plato didn t have a good answer to this question. He said that the beautiful things participate in Beauty and left it unclear exactly what it is to participate. It has been a metaphysical puzzle ever since. Aristotle Plato s pupil found the idea of forms out there making things down here have the properties they have so bizarre that he rejected Plato s realm. He agreed that there were forms but that they inhabited the same single reality. They were not material, things however. Furthermore, since there are many beautiful things, he had to say Beauty is in every beautiful thing. This violates our intuition that something can be in at most one place at one time. This problem how to make sense of having properties in common is known as the Problem of Universals in contemporary philosophy. Page 22/109

23 Chapter 3: Problems with Plato - Summary Summary Innate ideas may not be so strange after all. Perhaps we need some ideas to get started. There is evidence to suggest we have evolved minds that are pre-programmed with a lot of clever stuff. Geometrical truths are objective, just as truths about cats are. Circles cannot be ideas in the mind. Even Socrates doesn t think there are forms for everything. This makes us wonder whether they are needed at all. Page 23/109

24 Chapter 4: Classical Rationalism: Descartes - Introduction Chapter 4: Classical Rationalism: Descartes Introduction Plato lived in Athens in the 4 th century B.C. We re going to skip over a lot of history and jump to the 17 th century A.D: the century of the Scientific Revolution. Two philosophical positions, Rationalism and Empiricism, were born in the way that we understand them now. We are going to focus first on Rationalism. To put it in its simplest terms, Rationalism is the view that knowledge of reality cannot be grounded in experience alone but must fundamentally be grounded in reason. Knowledge demands certainty and the senses cannot deliver it. Our faculty of reason is able to grasp basic certainties by intuition. From such intuitive knowledge, we can demonstrate or deduce new knowledge. The model here is a geometrical one. We start with self-evident truths or axioms and deduce new truths or theorems. Like Plato, Rationalists thought that we had innate ideas and knowledge of reality which reason essentially uncovers and develops. Such an approach is known as foundationalism in epistemology. We are to consider our beliefs as forming a skyscraper. What keeps each floor up is the one below until we reach the foundations. The floors are our theorems. Asked why we should believe them, we can point to the floor below for support. Asked why we should believe those lower theorems, we ultimately point to the foundations or axioms which ultimately support everything. 1 Unlike Plato, they did not believe in the forms. They differed considerably over what they thought reality did look like. Descartes shared the popular view that reality contained matter in motion. The colours, tastes, smells and so forth that we naively think are in things out there are really just ideas in our minds. Our senses thus present reality to us in a confused way. Reason clearly reveals its deeper structure. Descartes was a philosopher, a mathematician and a scientist. It might seem odd that someone who thinks only reason can give us knowledge of reality should be called a scientist. Isn t science all about observation and experiment? Descartes would have replied that observation and experiment will be needed to establish particular theories, such as how light or the weather works. But it all rests on more basic metaphysical truths that only reason can establish. For example, only reason can establish that there is a world out there at all; for all that our senses could tell us, it could be a giant illusion. Like many at the time, Descartes thought the world was created by God and that we can deduce basic facts about it by reflection on God s nature. Ultimately, our picture of reality should make rational sense because it has been designed by a rational being who has given us the power of reason to enable us to find out about it. In this chapter, we will look at some of Descartes thoughts. He will argue that The senses cannot be trusted to deliver certainty. Reason grasps basic truths: that I exist, that God exists and that the external world is a world of material substances. Descartes: Scepticism about the Senses René Descartes ( ) was a pioneer scientist and philosopher. He wrote books on meteorology and on anatomy. His discoveries were plainly scientific. Yet he argued that it is only because we have the power of reason that we can gain any knowledge at all. Reason allows us to get a grip on the universe in a fundamental way. Our sensory experiences then can fill in a lot of the details. The senses by themselves cannot yield knowledge. Page 24/109

25 Chapter 4: Classical Rationalism: Descartes - Descartes: Scepticism about the Senses Like any philosopher, Descartes wants knowledge. He suspects that he has many false beliefs. He needs to weed them out. His method is to challenge each thing he believes to see whether it is completely certain and indubitable. This is known as the method of doubt. If anything can be found that cannot be doubted then it must be true and is hence something we can know. So, although I think I know that Caracas is the capital of Venezuela, I can imagine that I in fact don t. Perhaps my memory of having seen it on a map is false. Perhaps I am confusing it with the capital of another South American country. For all I know, what I think is true might be false. To doubt whether something is true is to be sceptical about it. As we saw in chapter 1, a philosophical sceptic is one who says that knowledge is impossible because we can never rule out all sources of doubt. Descartes plays the sceptic to argue that all sensory beliefs are dubitable and hence that the senses are not a source of knowledge. In the first chapter of his book, the Meditations, he launches an attack on our common-sense faith in the senses in three successively more destructive waves, known as the waves of doubt. Wave 1 Descartes observes that most of what we have learned, we have learned through the senses through experiencing the world with our senses of vision, smell, touch, feeling and hearing. Descartes then remarks: But from time to time I have found that the senses deceive, and it is prudent never to trust completely those who deceived us even once. For example, as he later says in Meditation VI, when he is considering why we have such faith in our senses: Sometimes towers which had looked round from a distance appeared square from close up; and enormous statues standing on their pediments did not seem large when observed from the ground. [CSM II 53; AT VII 76] There are three ways in which our senses might be considered imperfect. Fallible: we can misperceive things. We are all familiar with the experience of not seeing things as they are. I might see a tower in the distance that looks round but is in fact square. Limited: we cannot see with the same degree of accuracy as an eagle. All sense-organs have operational limitations. Subjective: senses vary from one person to another. Some people are colour-blind, for example. Animals have senses we lack. Might they see parts of the world that we can t? From Wave 1 to Wave 2 Descartes draws our attention to familiar imperfections of the senses. But he does not expect this alone to convince the reader. For the situations in which our senses let us down are both identifiable and explicable. If you are far off from the tower, you know you should get closer because your eyes work best when they are focusing on nearby things. If you are not sure whether there is a badger or a fox in your garden because it is dark, you know that this is excusable because your eyes are designed to work in good lighting. Descartes observes that he currently is not in a bad condition for judging how some things look. He is sitting comfortably in a room brightly lit by a fire. How could he be in error about this? He would be no better than a madman, he says, if he doubted that he really did know where he was. Wave 2 In order to raise the idea that he really might be mistaken about whether he is sitting before the fire, Descartes needs to go beyond the familiar fact that we make mistakes when conditions aren t ideal. He Page 25/109

26 Chapter 4: Classical Rationalism: Descartes - Descartes: Scepticism about the Senses introduces the famous Dream Hypothesis. He could be dreaming that he is sitting by the fire. Any visual experience you could have in waking life could be had in a dream. From Wave 2 to Wave 3 If he is dreaming, then perhaps the chair is not really there. (He could of course be dreaming he is in his chair having fallen asleep in the chair itself.) Perhaps nothing he thinks is there really is there. Descartes does not go this far. When we dream, our minds are like artists, creating unreal images. But artists do not create everything in a picture. They manipulate colours and shapes. Descartes concludes that, although the particular things he is dreaming about may not exist, their general features ( certain other even simpler and more universal things ) do: This class appears to include corporeal nature in general, and its extension; the shape of extended things; the quantity, or size and number of these things; the place in which they may exist; the time through which they may exist, and so on. In other words, dreams present objects in time and space. Objects are extended, shaped and coloured things. Time, space and extended, shaped coloured and objects must therefore exist as the inspiration for Descartes dreams. He cannot doubt this. Descartes concludes this wave by spelling this out a little further: For whether I am awake or asleep, two and three added together are five, and a square has no more than four sides. It seems impossible that such transparent truths should incur any suspicion of being false. So, the truths of mathematics and geometry are still knowable, whether he is awake or dreaming, because they are true, regardless of whether he is awake or dreaming. So, even if he is dreaming, there is much he can be certain of. Wave 3 Descartes now pushes things farther. God is omnipotent and so surely has the power to deceive me about everything. Now, some will object that God would not do that to his creatures. God is good. But God allows me to be deceived sometimes this we know from the familiar imperfections of the senses raised in Wave I. So, there s no obvious reason to say that total deception is no more inconsistent with God s goodness than partial deception. Alternatively, says Descartes, suppose that there is no God and that I am here by chance. To put it a modern framework: suppose I am the product of evolution rather than design. Then since this cause is unintelligent, it is more likely that I am imperfect than had I been designed by an intelligent being, hence more likely that I could be the victim of a global deception. To fix the idea in his readers minds, he invokes a celebrated future: the malin genie or the cunning (or evil) demon: a God-like figure whose single aim is to deceive Descartes. The demon has the power to fool Descartes into thinking that he exists in a world of extended, shaped and coloured objects in space and time. There are no such things in reality. They exist only in the demon s mind and he is projecting them in to Descartes mind. I will suppose therefore some malicious demon of the utmost power and cunning has employed all his energies in order to deceive me. I shall think that the sky, the air, the earth, colours, shapes, sounds and all external things are merely the delusions of dreams which he has devised to ensnare my judgment. Page 26/109

27 Chapter 4: Classical Rationalism: Descartes - Descartes: The Cogito and Self The Demon is like the Matrix. It has complete control over your thoughts. So, perhaps the real world is completely different from how it appears. Perhaps there are no coloured objects in the world beyond. Perhaps the ideas we have of colours, objects, time and space are mere products of the demon s mind. Perhaps too are all the truths of mathematics and geometry. If so, perhaps nothing can be known with certainty. Conclusion Descartes concludes that my sensory experiences of the world, no matter how rich and coherent, could simply be an illusion. If so, no sensory belief can be certain. If so, the sense can t give us knowledge. Descartes: The Cogito and Self In his second meditation (the second chapter of his book), Descartes says that if he could find just one thing he was certain of, then perhaps he could use that as a foundation to prove many other things. He compares himself to Archimedes, reputed to have invented the lever, who said that if he was given one fixed point, he could move the earth: the fixed point would be the fulcrum for his lever. The senses have been ruled out as a source of knowledge. All that is left is reason: But I have convinced myself there is absolutely nothing in the world, no sky, no earth, no minds, no bodies. Does it follow that too do not exist? No: if I convinced myself of something then I certainly existed. But there is a deceiver of supreme power and cunning who is deliberately and constantly deceiving me. In that case I too undoubtedly exist if he is deceiving me; and let him deceive me as much as he can, he will never bring it about that I am nothing so long as I think that I think I am something. So after considering everything very thoroughly, I must finally conclude that the proposition I am, I exist is necessarily true whenever it is put forward be me or conceived in my mind. [Meditation II: AT VII 25: CSM II 16-17] Descartes claim is often expressed as I think therefore I am. 2 The claim is known as the cogito because in Latin (in which Descartes was writing), the above is: Cogito, ergo sum. What Descartes claims to know is that he exists. It is impossible to doubt it. To doubt that he exists means to try to think it false. To think it false is to think. But if I think, I exist. Put another way, in being conscious of my thoughts, I am conscious of me as the thinker. So, whether I am consciously wondering or fearing or even doubting, I am thinking in some way and conscious of me. This supposes, of course, that I can t be wrong in thinking that I think. But surely I can t! If there is a conscious thought, I am aware of it: that s what it is to be conscious. To try to doubt that I am conscious and thinking is to consciously think a doubting thought and so self-defeating. Thinking I am not thinking is like saying I am not speaking. Note that consciousness is vital. We can perhaps imagine lesser creatures or machines who have thoughts in the sense of processing information but are not aware that they are thinking. They could spend their whole lives unaware that they exist. But we are conscious and so cannot help but catch ourselves thinking and existing. Where does the certainty come from? Descartes says, from a simple intuition of the mind. It is like grasping that 1+1=2. A thinking thing must exist. Any attempt to doubt it fails and so it must be true. But what is the thinking thing or I that Descartes is certain exists? Descartes says that he knows that he exists as a conscious mind or a thinking thing. He is that inner self that is where thoughts and feelings happen. He is an embodied mind but the body is inessential. The mind can survive the death of Page 27/109

28 Chapter 4: Classical Rationalism: Descartes - Descartes: The Wax the body, this being a commonly-held religious belief at the time, of course. So, the mind or self is one thing, the body is another. Descartes is emphatically clear that the mind is not the brain. The brain is a material thing: a lump of extended stuff. The mind is an immaterial thing. Descartes reasons that the essence of mind is conscious thought: that is, what makes a mind a mind is that it thinks. The idea I have of myself as a thinking thing is not something I gain from experience. I am simply aware of myself as a thinking thing. It too is an innate idea. Descartes: The Wax Having established his own existence, Descartes spends the rest of the book proving that the real world exists after all. We are not dreaming and there is no malicious demon. Does this mean that the senses are alright after all? No. Descartes tells us that reason perceives material things, not the senses. You might think that this sounds absurd. If you took away my senses, I would not be aware of anything. Reason is surely what receives the data from the senses. It is not an organ of perception! Descartes would not deny that, senseless, I would perceive nothing at all. His point is more subtle. To reemploy a phrase we have used often, we see the world with the senses confusedly. It is reason that enables us to see it more clearly. The senses present us with constant change yet we do not think that nothing stays the same. Reason gives us our grip on the stability beneath the changes. Descartes makes this clear with the famous piece of wax argument. Sitting in his chair, Descartes examines a piece of beeswax. This is something whose nature he knows "more distinctly" surely than that of his mind. It has a certain smell, taste, appearance and feel and made a noise when tapped. But once warmed, it loses all of these qualities and takes on new ones. If the wax were nothing more than the sum of its sensory qualities, then we would have to conclude that the original piece of wax had been destroyed and a new piece of wax had been created. "But does the same wax remain? It must be admitted that it does; no-one denies it, no-one thinks otherwise. So what was it in the wax that I understood with such distinctness? Evidently none of the features which I arrived at by means of the senses: for whatever came under taste, smell, sight, touch or hearing has altered yet the wax remains." (CSM II: 20) The difference between change and destruction is familiar to everyone. It is part of our basic idea of a thing or substance that it can persist through change. But the idea cannot come from experience. If all we had were senses, we would experience constant change. We could not learn the idea of something remaining the same despite changing. So, idea of a thing or substance must come from somewhere else. You might think that our imagination might help. Imagination is the mental ability to create pictures (or sounds, smells, etc.). It is not the faculty of reason. It is a sensory ability. Consider again the pre-fire wax. What makes me know it is the same wax afterwards is that I am able to imagine the wax with a different appearance. Generalising, I see a world of things that change but I am able to keep track of them and think of them as the same because they change in ways that I can imagine. Descartes dismisses this as a plausible suggestion: "[For] I can grasp that the wax is capable of countless changes of this kind; yet I am unable to run through this immeasurable number of changes in my imagination."(csm II: 21) Call the pre-fire wax A and the post-fire wax B. Now imagine doing something different to the wax, such as turning it upside down so it looks different. Call this C. And so on. If there were (e.g.) ten ways the wax could look, then perhaps I could, having seen the wax for the first time, imagine all other nine configurations and so know, when I see one of them, that it is the same wax. But there are not ten ways, of course. There are well, who knows? If not infinitely many, certainly a large and unclear number. So, my ability to track objects can t be down to my having imagined all the ways that they could look. Page 28/109

29 Chapter 4: Classical Rationalism: Descartes - Descartes: God & The Ontological Argument The right answer is that we have an idea of a material substance that is innate. What is this idea? It is the idea of "something extended, flexible and changeable." Substances are things that take up room or fill space and can undergo changes. We don t learn this from patient experience of the world. It is an idea we are born with through being so created by God. In sum, the complete story is this. Reason tells us that things are filled bits of space. We know what sort of world we are dealing with. The senses deliver us information about the world. The mind makes sense of it by assigning the right sensory clothes to the right objects underneath. 3 Descartes: God & The Ontological Argument Descartes, like all thinkers of the time, believed in God. The God in question is known as the God of classical theism. In brief, it is the traditional Catholic conception of God as a infinite or perfect being: omniscient, omnipotent, omnibenevolent, eternal and unchanging. As with the idea of a substance, the idea of God is something else that we only have through reason and which must be explained as an innate idea. Descartes argues in two places that God exists and that God is a perfect, infinite being. God is, for example, omnipotent: there is nothing beyond his power. God s power is perfect and infinite because he has all the power any being could have. Descartes argues that we can deduce that God exists from the very idea of God. It is called the ontological argument: 1) We have a clear idea of God as a perfect, infinite being. 2) Examining this ideas, we find that one of God s perfections is necessary existence. o God is perfect so has the best of everything. It is more perfect to exist than not exist. And it is more perfect still to be something that has to exist than something that merely happens to exist. 3) So, God exists, necessarily. The important point for our purposes is that Descartes deduces by pure reason the existence of a real thing from a concept. Empiricists, as we shall see, think this sort of thing is wholly unacceptable. The only way you can determine what is real is by experience. Descartes: God & The Cosmological (Trademark) Argument (*) Descartes first argues that God exists. The argument is complex but it boils down to a familiar type of argument known as a cosmological argument. The central concept of a cosmological argument is the concept of causation. The most familiar version of this argument runs as follows: 1) Things change or come into existence because they are caused to do so. Alternatively: things don t simply happen or pop into existence. o For example: an apple falls because the Jim shakes bough and a fire comes into existence because lightning strikes the tree. o In symbols, we can say: X causes Y. 2) But what s responsible for X? Something must have created or caused X to be the way it is: o For example: what caused the Jim to shake the bough? Perhaps it was his desire for an apple. And what caused the lightning to exist? A storm. 3) So, we move from X Y to W X Y as we go back in time. 4) But we can ask the same questions about W. 5) So, we keep moving back and back and back 6) but we can t go back forever. Something must have been a First Cause. This is God. It might help to think of dominoes toppling. There couldn t be infinitely many dominoes that have always been toppling. Something must have started it all off! Page 29/109

30 Chapter 4: Classical Rationalism: Descartes - Summary Descartes version doesn t focus on time but on complexity. We are finite or limited beings. We can do and create many things but we can t do or create just anything. Now, what goes for things goes for ideas. Ideas come from somewhere. They are caused too. And there is no difference between the complexity of a thing and the idea of it. Consider a really complicated machine. The blueprint for a machine in the inventor s head is just as complex as the machine itself. To create one is no harder in principle than to create the other. A simple person can t create the idea of a complex machine. To create something complex, you need to be at least that complex. It is like buying something. If a book costs 10, you need at least 10 to buy it. Now, we all have an idea of God as an infinite being. Where does this come from? It is not from the senses. We do not experience the infinite. Our senses give us detailed but limited information. Nor is it an idea we have thought up, as we might think up an idea for a machine or a fictional character. For our minds are finite and the idea of God is an infinite being. God is simply too complex for us to have invented him. So, the idea of God must be an innate idea and our ability to understand God comes from the power of reason we have to explore this idea. Let s put this in a summary form: 1) Ideas, like things, must be caused. 2) The cause of an idea must be at least as complex as the idea itself. 3) God is infinite and we are finite. 4) We can t have invented the idea of God. 5) We have not sensed God. 6) So, the idea of God must be innate. Again, Empiricists will be wholly opposed to this conclusion. No ideas are innate. We build up an idea of God from our experience of the world. Summary Descartes is the father of classical rationalism. He tells us that the senses are limited and fallible and so not sources of knowledge. We have certain key ideas (my)self, substance and God that cannot be explained as being gained from experience or imagination. They are innate ideas. o (All ideas are innate, as we shall see in the next chapter.) Descartes rationalism is clear: reason determines what exists (self, God, substance) and what it is like. Knowledge begins with intuitions from which we demonstrate new truths (such as that God exists). The fundamental knowledge of reality comes from reason not experience. Questions 1) Below are some claims I reckon you think you know. Imagine ways in which it could turn out that you are wrong: o Oranges grow on trees. o Iceland is an island. o The London Eye existed yesterday. o You have bones in your foot. 2) Is there anything you can do to establish whether or not you are dreaming right now? Page 30/109

31 Chapter 4: Classical Rationalism: Descartes - Questions 3) Surely we can be certain that we have bodies. I merely need to focus on the sensation I have right now of a twinge in my big toe. Is there any way you can have a big toe sensation without a big toe? 4) Consider games like Calll Of Duty. The game-world is full of things. How can we use this to cast doubt on Descartes claim that beneath how things appear there is a substance that reason grasps? 1 What alternative is there to foundationalism? The traditional competitor though it emerges much later is coherentism. According to the coherentist, no proposition is self-evident. What gives us reason to believe a proposition is how it fits in with others. So, the reason I believe that today is Monday is that it fits in with all my other evidence: the classes I have taught, the paper I have read, the notes in my diary, and so on. The more all of my beliefs knit together into a good story, the more likely they are collectively to be true. This way of putting it brings out the most obvious problem. There can be coherent fictions. So, coherence is no guarantee of truth. Of course, there is more to say than this but not here. 2 Indeed, although Descartes doesn t put it this way in the Meditations, he does elsewhere, such as in the Principles of Philosophy: [We] cannot suppose that we, who are having thoughts, are nothing. For it is a contradiction to suppose that what thinks does not, at the very same time when it is thinking, exist. Accordingly, this piece of knowledge I am thinking, therefore I exist is the first and most certain of all to occur to anyone who philosophizes in an orderly way. [Principles of Philosophy I.8: AT VIIIA 7: CSM I 194-5] 3 Descartes wouldn't say that only through having senses can something perceive the material world. God lacks the senses but "perceives" the world through some faculty of divine intuition: he knows immediately how everything is in the world. How does he know it? Does he intuitively know the location every last atom in space, in a mathematical way? Or does he share our ability to experience colours and tastes? It seemss hard to make sense of God having sensations without sensory organs, so perhaps the former. Page 31/109

32 Chapter 5: Classical Rationalism: Problems with Descartes - Introduction Chapter 5: Classical Rationalism: Problems with Descartes Introduction In this chapter, we ll examine Descartes arguments and raise some criticisms. Here s what we ll say: Can we resist the sceptical arguments? We do not know what the self is. Perhaps we can resist substances. Could reason be faulty? Dreaming and the Demon: Can We Resist? Descartes suggests that philosophically speaking we might be dreaming even when we feel most awake. Really? Dream-like? John (J. L.) Austin argued that there is a difference between our experiences while dreaming and while awake. This is supported by the very notion of a dream-like quality. If dreams were not qualitatively different from waking experience then every waking experience would be like a dream. This is not the case, though. We can distinguish dreaming from waking states. However, Descartes is not claiming that there is no way of drawing a distinction between any dream and a veridical experience. The point of the dreaming hypothesis is not to suggest that all dreams are indistinguishable from waking experience. It is rather that some dreams cannot be distinguished from one s actual waking experience. Therefore, there is nothing in our actual experience and the beliefs that we possess which will enable one to judge with certainty that one is (right now) having a veridical experience/not dreaming. Think about it. Right now you re awake and doing some philosophy. What is it about your waking experience and the beliefs that you have that underwrite certainty in your actually being awake? Perhaps you think there is some test which can establish that you are awake. Maybe you could try pinching yourself, kicking the table and so on. The problem with appealing to some test is that it is conceivable with respect to any such test that I could dream it is satisfied. So, the pain I feel on pinching myself does not guarantee that I am awake because I could be dreaming that I am carrying out the test. It is enough for the development of doubt that with respect to a certain kind of dream we have no clear signs for distinguishing being awake from being asleep. Deception requires truth A further challenge due to Austin concerns the notion of deception. It is possible that any ten-pound note I receive could be a counterfeit note. But it is not possible for every ten-pound note to be a counterfeit note. Counterfeit notes can only exist when there are lots of real notes for them to be replicas of. In the same way, the practice of telling lies requires that people typically tell the truth and except each other to tell the truth. Otherwise, lies could not "sneak in". So, in general, a deceptive practice is parasitic on a non-deceptive practice. Page 32/109

33 Chapter 5: Classical Rationalism: Problems with Descartes - The Demon: Can We Resist? Back to dreaming. If we can recognise dreaming as a form of deception, that must mean there is the corresponding non-deceptive practice: being awake and in the real world. Although it could be true at any moment that I am dreaming (and mistakenly thinking I am not), it could not be true all the time. Counterfeit notes require real notes, but I still can't tell whether the bank note in my pocket is real or counterfeit. Similarly, even if there must be waking experience, I am not able to tell whether this is an example of waking experience. Couldn't I appeal to the coherence of this experience, in the sense of how it fits with all my memories? No: they could be part of the dream too. Do we at least know that sometimes I am awake, even if I don't know when? Yes: at this stage in Descartes' journey, we have just waking and dreaming on the table and so, yes, there must be waking experience. But, to look ahead, no: what we can know is that there are two distinct types of experience, one parasitic on the other, but neither need be "real life". Suppose you are wired into the Matrix. The machine feeds you Stream A of experiences ("waking life") and periodically switches into Stream B ("dreaming"). You learn the concept of dreaming in reaction to Stream B but neither are "real life". The limits of dreaming Norman Malcolm claimed that we cannot make judgements or form beliefs while dreaming. If I am dreaming I cannot have beliefs or doubt that I doing such and such. So, from the fact that, say, I doubt that I am awake I can conclude that I must be awake. The difficulty with this objection is that we do seem to be capable of making judgements and forming beliefs while dreaming, especially when we have lucid dreams. The Demon: Can We Resist? More worryingly, Descartes could be globally deceived by an all-powerful demon, which we can think of as the Matrix. Now, if we can t tell whether we re dreaming, we clearly will be unable to rule out the Matrix. But let us suppose we can somehow rule out the possibility we re dreaming. Perhaps dreams do feel different or that we are in some way limited in dreams. Does the same apply to the Matrix? Could there be some sort of test we can perform some sort of pill we could swallow? The Magic Test Could there be a test I could complete to prove I am not dreaming? To know that a putative test T is such a test, I would have to have the ability to know and not be deceived. So, I would need to know I am not dreaming first to know that T is or isn t such a test. Let us suppose that there is a test and I that I know there is (somehow). Let us suppose I know that T is that test. Then I would still have to know, in performing T, that I have performed it correctly. But, once again, I can t know this. I would need another test T*, the completion of which would prove that I did T correctly. But to know that T* works would take us back to the first paragraph. (And if I know that T* works, I d need a test T** to know that I ve done it correctly; and so on.) In conclusion, there is no easy way out of the dream or demon arguments. The Self Descartes claims to prove that he exists. But what is he? Descartes tells us that he is a thinking thing. His body may be an illusion but his mind isn t. Could we argue that we know we have bodies because we have sensations? No. As Descartes points out, people who have lost a leg can still have sensation as if Page 33/109

34 Chapter 5: Classical Rationalism: Problems with Descartes - The Wax from their big toe. These are called phantom limb sensations. Although a big toe pain feels as if it is in the toe, the pain is really in the mind. But what is he? Is he a person, perhaps? Some people think that what makes us people is not that we are bodily things. My mind could be transplanted into a different bodies and I would still exist. What makes me me are mental attributes: my tastes, my views, my beliefs and my memories. These are like data on a hard-disk: essentially portable. But Descartes cannot conclude he is this sort of thing. For all he knows, his mind may not have existed a second ago. All his tastes, views, beliefs and memories could have been created by the demon. He feels as if he has been around for a while but it is just another illusion. If this is so, then the self that Descartes has proved exists turns out to be a rather unclear thing. Descartes can think, I exist! and thereby express that he is conscious, but what exists and is conscious remains puzzling. Perhaps the self is yet another illusion. The philosopher Hume thought so, as we shall see. The Wax In the questions at the end of the previous chapter, I asked you to consider games like Call Of Duty. Here s why. In the game-world, you interact with things. But all that is really there are shapes on a screen. The computer cleverly adjusts the shapes to give you the feel of moving amongst a world full of things. Now step out of the game and into the real world. All we see are coloured shapes. They behave in a way that makes us think in terms of substances: things that exist in space and through time and which can undergo some changes. But perhaps that is merely how our minds make us see things. Our brains are very good at making us see what is not there. Consider the following image: You should see a white triangle. But that is your brain interpreting the image in a certain way, as there is no triangle on the page. Or look at the Ames room illusion: Page 34/109

35 Chapter 5: Classical Rationalism: Problems with Descartes - Could Reason Be Faulty? The two men here are the same height. You are fooled by the design of the room. The back wall actually slopes away at an angle. You your mind assume that it does not and that it is like any back wall: at right angles to the others. In so doing, it reduces the apparent size of the man. (Here s a diagram explaining how it works ) So, our minds simply project structure onto the world rather than detect it in the world. This is exactly what Hume thought, as we shall see. Indeed, we will see that Hume is the perfect opponent of all the Rationalists claims to knowledgee of a reality beyond experience. We can only know, he said, what we can find in experience. Could Reason Be Faulty? Descartes and others write as if reason is immune from error. But we all know that reasoning is hard and that we make mistakes. Consider the following three questions: 1. You toss a coin ten times and get: TTHHTHTTTH. (H = heads, T = tails.) Your friend tosses a coin ten times and gets HHHHHHHHHH ten heads in a row! Was your friend luckier than you in getting this pattern? 2. Every Saturday, Jim goes to the pub to watch the football. Jim s in the pub today watching the football. So, it must be Saturday. 3. Below are four postcards. Each postcard has a number or letter written on either side. You can see: 3 A 4 G You are now told the following: if a card has an odd number on one side, it will have a vowel on the other. Which card or cards would you need to turn over to see whether this claim is true? Many people get the answers to these questions wrong. What seems intuitively obvious may turn out to be completely false. We needn t come up with logical or mathematical puzzles to prove this either. It was intuitively obvious to many people once that the Earth was still. Rationalists like Descartes recognised that reason could be misled but believed that if we took pains to use it carefully, we could not be mistaken. But one might then say that if we took pains to use our senses properly, the same is true. We must check that we are sane and sober, that the conditions for judgment are proper, and so on. Page 35/109

36 Chapter 5: Classical Rationalism: Problems with Descartes - Summary Summary In conclusion: It is hard to resist sceptical arguments. Descartes does not have as clear a conception of substance or self as he might like. What is intuitively obvious to reason may not be true. Questions 1) Have you ever had a really lifelike dream? 2) Have you ever had a real-life experience so strange that it felt like you were dreaming? 3) Have you ever been unsure whether a memory of doing something is real or imagined? 4) Do you think that you could still exist in another body if you had the same mental states? 5) What if you lost your memories but retained the same body? 6) Can you think of any examples of things you once believed as obviously true or that others have believed as obviously true that we now don t believe are true? Page 36/109

37 Chapter 6: Reality and Rationalism - Introduction Chapter 6: Reality and Rationalism Introduction We have seen Descartes and Plato giving arguments for the existence of ideas graspable only by reason. In this chapter, we will broaden our view of Rationalism. We shall look briefly at Leibniz. We shall also introduce some key terms: a priori and a posteriori and necessary and contingent. A Priori and A Posteriori Rationalism is the view that at least some knowledge of reality comes from reason, not experience. Remember that by comes from here we mean is grounded in or is justified by. Our mind contains ideas not gained from experience but which are innate. Knowledge begins with intuitions, where we simply see truths. I might intuit that I exist by pure reflection. Or I might see by intuitions connections between concepts, such as that a square has more sides than a triangle. From our intuitions we can deduce new truths and build up our knowledge just as we can build upwards having laid the foundations. In gaining knowledge, we gain something infallible. We gain an insight into how reality is. By this, we mean the timeless, changeless structure of reality underneath the incessant changes that the senses reveal to us. We learn about what things are, not merely where they are or how many of them there are. When we reason on the basis of concepts alone we are said to reason a priori. For example, when I deduce that 51 is not a prime number because it is divisible by 3, I reason a priori. I am playing with the mathematical concepts in my mind. I therefore know that 51 is not prime a priori. This means that my justification for believing it comes from reason. Consider now the claim that there are 51 books on my shelf. This is not something I can prove by pure reason. I can hardly sit in an armchair and think about the concepts 51, book and armchair and work out whether it is true or false! I need to see what the world is like. If my senses report that there are that many books and that is good enough for me to be said to know that there are that many books, then my knowledge is a posteriori: my justification for believing it comes from sensory experience, not from reason. The distinction is at the heart of our subject. Rationalists say Empiricists say There is knowledge of reality that is justified by reason and so independently of experience: this is a priori knowledge. A priori knowledge is of the highest grade as it is unpolluted by sensory experience. Our senses alone are unable to deliver certainty or infallibility. There is no knowledge of reality justified by reason and so independently of experience. All knowledge of reality is justified by experience and so is a posteriori knowledge. There is a priori knowledge but of concepts/ideas, not reality. (E.g. a square has four sides, 2+2=4.) A priori knowledge is the highest grade but we just have to accept that we can t have it when it comes to reality. Our senses are fallible but we just have to live with it and do our best. Page 37/109

38 Chapter 6: Reality and Rationalism - Science and Reality Science and Reality What s reality like? Common-sense tells us that the world is full of things that have sensory properties: colours, smells, tastes, sounds as feels. They are arranged in space and last through time. Prior to Descartes, the popular view was that reality was in effect as common-sense would see it. A red tomato has something in it redness which makes it red and which, by travelling to the eye, makes me see it as red. The redness I see is just like the redness in the tomato. It resembles it. The tomato has a certain taste and feel too. All of these are in the tomato. They are the properties or qualities of the tomato that make it what it is. In the 17th century, philosophers and scientists developed a very different view of the world, one that has lasted (albeit significantly modified) until today. They thought of the tomato as a bunch of colourless, tasteless, noiseless particles in space. The redness of the tomato is not a pure something in the tomato. The process is more complicated. Light also a stream of particles hits the tomato and some are reflected into the eye. They hit the back of the eye triggering more particles to flow up the nerves into my brain. My brain recognises the distinctive pattern of particles and paints that bit of my world with my internal red paint. The redness of my sensation my red idea is in me. The redness of the tomato is its molecular configuration, as we would now say. 1 They are utterly unalike. When we sense the world, our experience represents it without resembling it. In this respect, my idea of red is like the word red. It is nothing like the colour but it is associated with it in a special way. Speakers of English follow a rule which means that they use the word for that colour. The rule is arbitrary, of course. In Polish, I would use the word czerwony. But it is a rule that you have to stick to in order to play the game of speaking English. A tomato is a bunch of atoms, each of which has a certain size, shape and mass and in virtue of which the tomato does too. Qualities like these are really in the tomato. They are primary qualities. They exist independently of us. When God was designing the world, he designed using just these qualities. Then there is the redness of the tomato. This is a secondary quality. A tomato is red because it causes a certain type of sensation in certain creatures. It is only red because we see it that way. It is a secondary quality of the tomato. My idea of the tomato s shape resembles the tomato s shape. Ideas of primary qualities do resemble. My idea of its redness does not. I think of the redness my sensation as out there, in the tomato. But out there, in the tomato, there are just specially-arranged particles. As we will see, both Rationalists and some of their Empiricist opponents such as Locke believed in this picture. Why? They appealed to a variety of arguments, some of which went back nearly two thousand years, to hammer home the point that the colours, smells, etc. we think are out there and in the things in the world are really in us. Condition relativity arguments: A colour (taste, etc.) cannot be in the thing itself as the colours of things change with conditions. o Example: the colours of your clothes will vary as the lighting conditions vary. o Example: "Take some porphyry (a purple-white rock). Turn the lights off. You can no longer see the colours. Have we changed the porphyry? No. So, the change is in us: we no longer have the ideas of purple and white." (Locke, ECHU, II, viii, 19) Different subject relativity arguments: A colour (taste, etc.) cannot be in the thing itself as different people experience different things. o Example: some people like tuna, others do not. There cannot be one taste else everyone would react the same way. So, people experience different tastes. Page 38/109

39 Same subject relativity arguments: Chapter 6: Reality and Rationalism - Leibniz, Maths and Necessity A colour (taste, etc.) cannot be in the thing itself as one and the same person can experience it in two incompatible ways: o Example: put one hand on the radiator and the other on ice then plunge both hands into the same bucket of warm water. One hand will feel warm and the other cold. Is the water both hot and cold? No. Warmth and coldness are in us, not in the water. Pain-pleasure arguments: No-one thinks pains or pleasures are in things. But people think colours, tastes, etc. are in things. But there is no clear difference between them. So, we should conclude all such qualities are in us. o Example: if I draw near a fire, I experience warmth, which I think is a quality of the fire. But if I draw closer, I experience pain, which I don t think is something in the fire. We should think that neither warmth or pain are in the fire but ideas in me produced by the fire. They followed these arguments up by ones showing that not all qualities are in us but some are out there: "Divide a grain of wheat into ever smaller parts. Each part will still have extension, shape and solidity but we will destroy the taste, feel and smell of the wheat." (Locke, ECHU, II, viii, 9) "Pound an almond and you change the colour from white to grey and the taste from sweet to oily. Yet all we have done is re-organised the matter in the almond." (Locke, ECHU, II, viii, 20) In sum: By altering any object, you can destroy secondary qualities but you cannot destroy primary qualities. Primary qualities are not dependent on having a certain sense-organ but are common to all senses. In our idea of something (e.g. a tomato), our idea will resemble the thing as regards primary qualities (e.g. shape) but not secondary qualities (e.g. colour). The moral the Rationalists drew from this was the following: 1. We have ideas of red, warm, coriander, etc. 2. These do not resemble qualities in the world. 3. They do therefore not come from experience. 4. They are therefore innate. So, Descartes and Leibniz thus concluded that every idea is innate: from the simple sensation of red right up to the idea of God. Now, you may be thinking that this is mad. How can the idea of an ipod have been innate in Leibniz s 17 th century mind? Leibniz would have said that the idea wasn t in there, fully formed. But the ingredients for the idea of a substance, of its colours, feel, and so forth were all in there as ideas ready to be triggered by experience. The idea of an ipod is therefore also triggered by experience. Feed a mind certain sensory data and it will produce the idea of a small shiny box that does certain things. Leibniz, Maths and Necessity Perhaps no philosopher embodies Rationalism more than Leibniz. Starting from a small number of basic logical and theological principles, Leibniz worked his way to a detailed picture of reality. At the centre was his view that God exists and is perfect and that our minds are mirrors of God s minds. We have Page 39/109

40 Chapter 6: Reality and Rationalism - Necessity and Contingency innate ideas (copies of God s ideas which are also, in a sense, innate, as God doesn t learn anything) and reason allows us to uncover God s perfect reality. Reality as it seems is different from reality as it is. We shall come back to this point again shortly. We won t be looking at Leibniz s philosophy in any great detail. Like Descartes and many of the ancient Greeks he looked to, Leibniz was a mathematician of note. What impressed them all was the special nature of mathematical truths. It is not just that 2+2=4 but that it has always been true and always will be true. It is a necessary truth. A necessary truth must be true no matter how the world could have been. Leibniz observed that only reason can grasp such necessary truths, not the senses: Although the senses are necessary for all our actual knowledge, they are not sufficient to provide it all, since they never give anything but instances, that is to say, particular or singular truths. But however many instances confirm a general truth, they do not suffice to establish its universal necessity, for it does not follow that what happened will always happen in the same way From this it appears that necessary truths, such as we find in pure mathematics, and particularly in arithmetic and geometry, must have principles whose proof does not depend on instances, nor consequently, on the testimony of the senses, even though without the senses it would never occur to us to think of them. [Nouveaux Essais, 49-50] Leibniz s point is simple. Suppose I see a strange beast: a borsuk. It is black with four legs and has a stripe on its back. Do all such creatures have it? I see some more: yes. Can I conclude that all do? No. No matter how many I see, I might not have seen all of them. And even if I could scour the whole universe now, it would not prove that they could not change in future. Yet when I grasp that 2+2=4 or that the angles of a triangle add up to 180 º C, I discover something that is never going to change. I grasp something about all triangles even if I have only seen one. Here s the argument again: 1) Sensory experience can tell me how the world is now. 2) By memory, we can tell how the world was then. 3) This allows me at most to examine a finite number of (e.g.) borsuks or triangles. 4) That s not enough to deduce something about all of them, for things could change. 5) But when I know a necessary truth, I grasp something that won t change. 6) So, my knowledge can t arise from the senses. 7) So, it must arise from reason. Necessity and Contingency Leibniz was particularly interested in necessity. 2 He defined a necessary truth in two ways: One whose denial is a contradiction. One that is true in all possible worlds. Think of a possible world as a way that the universe could have been: a possible total history in God s mind. According to Leibniz, God chose one of the infinite possible designs in his mind (the best one, in fact) and actualised it. God chose a world with me in it but there are countless worlds in which my parents never met or my grandparents never met or in which the dinosaurs never became extinct; and so on. But no matter how God designs the world, 2+2=4 and a triangle will have three sides. These are mathematical and geometrical truths. They are true in all possible worlds. As for the first definition, suppose Subtract 2 from both sides: 2 2. That s a contradiction! Or suppose a triangle does not have three sides. It is an enclosed space with three angles. An angle is created by the intersection of two lines. Two angles can be created by one line intersecting another two. These other two must meet and create a third angle or they must be parallel and never meet. If the latter, there is no enclosed shape. If the former, we have an enclosed space with three angles and three sides which does not have, by hypothesis, three sides. That s a contradiction too. Page 40/109

41 Chapter 6: Reality and Rationalism - A Priori and Necessary: The Scope of Rationalism The opposite of a necessary truth is a contingent truth. In keeping with above definition, we can define it as: One whose denial is a not contradiction. One that is true in some but not all possible worlds. It is sunny today but it is not contradictory to say it is not sunny today. That is a way the world could have been. Note that we don t define a contingent truth as: One that is true in no possible world. Such a claim would be a necessary falsehood like 2+2=5 or a circle has three sides. A Priori and Necessary: The Scope of Rationalism There is a close connection between the a priori and the necessary. As Leibniz pointed out, only reason can grasp necessary truths. So, for him, all knowledge of necessities was a priori. Even Empiricists like Locke and Hume who did not share Leibniz s rationalism agreed, as we shall see. They simply differed over what necessities we can know. Hume argued that the only necessities knowable were either those in maths and geometry or trivial ones, such as a square has four sides. There are no necessary truths about reality to be known. We have just said that if it is necessary, it can only be known a priori. Does the reverse follow? It looks so. If I know it a priori, then my justification does not come from experience but reason. Reason grasps ideas and the relations between them which cannot change. My experience could vary this way and that: what reason grasp does not. So, what I grasp resists any change to how the world might be and so is necessary. Necessary truths are of particular interest to the philosopher. They say how things must be. Remember that Plato was concerned to find out what makes things what they are. He was not interested in whether there happens to be a cat in the garden but what must be true of cats: There s a cat in my garden: contingent truth (so what?) To be a cat, you must have four legs, whiskers and a moody attitude: necessary truth (interesting discovery about the nature of reality.) Mathematical and geometric truths are also necessary truths, as we have seen. So too, thought philosophers at the time, would be the laws of nature. It is a law that water freezes at 0ºC and a law that objects with mass experience a force of attraction between them inversely proportional to the distance between them, for example. Our universe looks like a well-oiled machine running according to such laws. A law says has things must be. So, laws look like necessary truths too. Finally, necessity even intrudes into morality. The search for the nature of good and bad is surely the search for what you must and must not do. The commandment thou shalt not murder, for example, is like a necessary truth: it says that you must not murder (if you want to be good). So, if we re after necessary truths and only reason can grasp necessary truths, then it looks like Rationalism is the way forward. Here s a summary of the sorts of things claimed as knowable a priori: Theology: truths about God, who is something beyond experience. E.g. that God is omnipotent.) Metaphysics: truths about the nature of reality. E.g. that a material substance is extension, that reality is not how it appears except in primary qualities, that there are non-sensible forms that unite kinds and properties. Page 41/109

42 Chapter 6: Reality and Rationalism - Reason and Introspection (Inner Sense) Mathematics: e.g. 2+2=4 Geometry: e.g. area of a circle = πr 2. Science: Descartes argues that the fundamental laws of nature can be deduced a priori from the nature of God. Logical truths. If all cats are mammals and all mammals are warm-blooded then all cats are warm-blooded. We do not need to inspect all cats and all mammals. We know this to be true by pure reflection. We understand the logic of all and if ; and that suffices. Moral truths. Rationalists such as Spinoza argued that basic moral principles are discoverable by pure reason. Reason and Introspection (Inner Sense) This leaves us wondering what we should say about the following claims: I am thinking. I am in pain. I am sensing a red disc. It is contingent that I am thinking and that I sense a red disc. I could never have existed and my experiences are otherwise. Yet I don t know these things by the use of my senses. I simply notice these things in my mind, so to speak. So isn t this the use of reason? So don t I know these things a priori? Descartes effectively would have said yes. He spoke of the natural light of reason showing us some ideas as clear and distinct: their truth shines forth. So, the whole is greater than the part would one such truth and I am experiencing a pain would be too. Other philosophers would have said no. They say that there is a difference between reason and what has been called inner sense, apperception and introspection. Reason is the supposed special power we have that enables us to grasp truths about reality out there. Introspection is the ability to become aware of one s own mental states in here. It literally means to look inside. I can become aware that I am in pain and it seems I can t be wrong about this. My mind is simply open to me. But I am not exercising reason here. If anything, it is like use a special inner sense: an awareness of my own experiences. So, my knowledge here is a posteriori. We will agree with these philosophers. Summary Knowledge justified by reason alone is a priori knowledge. We have a priori knowledge of reality, says the Rationalist. Some truths are necessary and only reason can grasp necessary truths. The world is not as it appears: the senses merely tell us of the secondary qualities of things. Reason is needed to get underneath to the primary qualities. All our ideas are innate. The necessary truths we seek with reason are in various areas: from ethics to metaphysics. Questions 1) Which of these do you know a priori? If Anna is taller than Barbara, Barbara is shorter than Anna. In Britain, it is typically colder in winter than in summer. Page 42/109

43 There is no largest number. A triangle has fewer sides than a hexagon. The dinosaurs are extinct. A dropped stone falls to earth. Nothing can be red and blue all over. Chapter 6: Reality and Rationalism - Questions 2) Which of these claims are necessary and which contingent? The part is greater than the whole. Tuesday comes after Monday. London is the capital of the U.K. Water freezes at 0 º C. Most people like chocolate. An isosceles triangle has two equal sides. 3) Jim says, Numbers are things invented by us. You can see that we ve done it in different ways. The Romans would write 2+2=4 and the Romans II+II=IV. What s wrong with his reasoning? 4) What proof do we have that the sun will rise tomorrow? 5) Think up some arguments for secondary qualities of your own with the following hints: Can the same thing taste different to you under different conditions? (Think about what you could eat beforehand.) Create an argument using pleasure and music or taste to prove that sounds and tastes aren t in things. The microscope was invented in the late 17 th century and opened up a whole new world to philosophers and scientists. How could you use a microscope to undermine the claim that colours are in things? 1 In modern terms, it goes like this. Light hits the vibrating molecules of the tomato and light of certain wavelengths is reflected. This light (which is colourless too it s just photons) stimulates my optic nerve via the retina which stimulates my brain and mind into action. 2 Leibniz actually said that every truth was necessary. That I am typing these words now is necessarily true. There is only one actual world God could have created, so everything that is true in this world must be true. On similar grounds, another Rationalist, Malebranche, said the same thing. Page 43/109

44 Chapter 7: Classical Empiricism: Locke - Introduction: From Rationalism To Empiricism Chapter 7: Classical Empiricism: Locke Introduction: From Rationalism To Empiricism Rationalists distrust the senses. The senses show us a changing world. The senses are limited and fallible. The senses show us what a bit of the universe is like here and now. Our collective memories can extend that a bit in space and time. Our power of reason enables us to transcend our limited perspective and discover deep truths about the reality in which we live. This distrust goes back to the ancient Greeks. Plato argued that the world revealed by the senses is a shadow-world. The real world is the world of the forms. The forms are the timeless and changeless essences of things. Beautiful things may come and go but beauty the idea of beauty will not. Only reason can access this world. The senses, to repeat, show us a world of change. They also show us a world of difference: beautiful things may look radically different and yet be both beautiful, showing us that beauty is not a feature obvious to our senses. Like all philosophers, Plato thought that the real world was not obvious but it was accessible. We can, with hard work, discover what reality is like. In the 17 th century, rationalist philosophers such as Descartes and Leibniz shared this dream. They believed that God had created us with the power to discover the truths about the reality we inhabit. Like Plato, they believed that we came pre-programmed with innate ideas about reality. By using these in-built ingredients, we can reason our way to the structure our reality. For Rationalists, therefore, our knowledge of reality indeed all our knowledge is a priori: independent of experience. Classical Empiricism was born in the same century as Classical Rationalism. Rationalists said that reason was primary and the senses secondary, Empiricists reverse the order. We are born as blank slates but with powerful minds ready to handle the sensory data from the world. Our minds organise experiences for us so that we can form concepts and by reflection on them, we gain ever deeper knowledge. Reason, in the form of the organising and reflecting mind, can only play with the ingredients provided by the senses. There is therefore no way it can go beyond them. Empiricists were buoyed by new movements in experimental science. By doing science, we find out how the world is. The world may be quite different to how reason suggests it ought to be. But that s just how it is. If our senses tell us that the world behave in such-and-such a way, then that s how it is. Reason cannot come in and tell us that, underneath, it must behave in a more rational way. At the same time, Empiricists dug themselves into a hole. What s before the mind are our ideas. We take our ideas to represent reality. But can we actually know that they do? Consider the following. You want to see what Paris is like. You find photographs on the internet. You watch reports on the television. You are not seeing Paris with your own eyes but via images. Now, if you go to Paris and see it with your own eyes, you can check whether the images you saw were true representations. But if all you ever see are images, then you can never be sure that they represent it properly. For all you know, Paris could be radically different. Indeed, it could not even exist but be nothing more than a fiction created by the French government. Locke took it that our minds were set up by God to give us ideas that do represent. Nevertheless, he said we need to be very cautious as we are easily drawn into error. Later Empiricists, such as Berkeley and Hume, said in very different ways that we cannot properly speak of a reality beyond our ideas. In this chapter, we will look at the father of Empiricism: Locke. We will say the following: There are no innate ideas and no innate knowledge. We can explain how we form concepts on the basis of experience. Page 44/109

45 Chapter 7: Classical Empiricism: Locke - Innateness Innateness Locke opens his master work, the Essay Concerning Human Understanding, with a sustained attack on the idea of "innate principles" (=true propositions innately known) and "innate ideas" (=innate concepts). Locke essentially poses a dilemma for the Rationalist: Either having an innate idea means the ability to form an idea, in which case no-one will disagree. Of course we have such abilities or we wouldn t be here now! But there s a big difference between having the ability to do something and having the something itself. I have the ability to learn Russian but I don t actually speak Russian. Or you claim that having an innate idea really means having an already-formed idea in our minds. But that s crazy! o Think of children, idiots and savages (those lacking an education). They don t understand these ideas and yet are otherwise perfectly normal. If we all have the same ideas, though, then surely we should all be geniuses at birth! o Think of how religious and moral beliefs vary from people to people. If we all had the same ideas imprinted in us, surely there d be one religion we d all recognise and no moral conflicts. Let s now work through some of Locke s points in detail If there are innate ideas and knowledge, there must some way we can distinguish them from non-innate ideas and knowledge. (For surely not all knowledge can be innate. My knowledge that I am called Matthew would be an example.) 2. Locke suggests that it is "universal consent". In other words, an innate truth is one we all recognise as true. 3. Locke now invites us to consider the truths that philosophers Rationalist philosophers would say are basic and undeniable truths. These are complicated truths like: o Mathematics: 2+2=4 o Logic: the whole is greater than the part. o Metaphysics: it is impossible for the same thing to be and not be. 4. Locke now points out that universal consent cannot be necessary for innateness. His reason is that "children, idiots and savages" are neither aware of such complicated truths nor understand them when they are presented to them. 5. Next, Locke points out that when it comes to moral and theological truths, such as murder is wrong and God is to be worshipped, we do not find agreement amongst people. Some very intelligent people believe in God and some do not. Amongst believers, there are very different conceptions of God. As for moral truths, these famously differ from community to community. Consider Herodotus' telling of an anecdote by Darius (note: not quoted by Locke): When he [Darius] was king of Persia, he summoned the Greeks who happened to be present at his court, and asked them what they would take to eat the dead bodies of their fathers. They replied that they would not do it for any money in the world. Later, in the presence of the Greeks, and through an interpreter, so that they could understand what was said, he asked some Indians of the tribe called Callatiae, who do in fact eat their parents' dead bodies, what they would take to burn them. They uttered a cry of horror and forbade him to mention such a dreadful thing. One can see by this what custom can do and Pindar, in my opinion, was right when he called it king of all. [Histories, 3.38] 6. Locke's point applies just as well to scientific, mathematical, logical and philosophical principles. Experts don't always agree and so the right answer (if there is one) is simply not one that everyone agrees to. Typically, the right answer is proven to be the right answer after a struggle and everyone slowly comes round to it. Page 45/109

46 Chapter 7: Classical Empiricism: Locke - Where Our Ideas Come From 7. Locke then points out that universal consent cannot be sufficient for innateness. Everyone believes that the sun shines. But this doesn t make it an innate truth. It is simply a truth everyone believes because of their experience of a common world. 8. Locke then points out that there are some ideas, and hence some truths, that surely require experience. Sensory ideas cannot be innate. Someone who has never eaten pineapple cannot imagine the taste. Someone blind cannot imagine colours. Illiterate and uneducated people can live their whole lives without ever thinking through (let alone appreciating the truth of) the supposed truths. 9. Next, God is meant to have imprinted these truths and ideas in our soul Locke first asks why an infinitely wise God would imprint metaphysical truths that are of no great use to us in everyday life. Why, next would he imprint moral truths that are not self-evident. Surely the world would be a better place if we all knew from birth what the difference was between right and wrong? (Finally, wouldn t God help us out by giving us some sign of what ideas are innate and which aren t? This would make philosophy a bit easier!) 10. Finally, Locke points out that if all that is meant by saying we have innate ideas is the ability to form ideas and by innate knowledge the ability to recognise immediately intuitively that some claims are true, then this can be accepted by everyone as it is trivial: o o Of course our minds have an innate ability to form ideas or we d have no ideas at all. There must be something in there to process the data given by the senses. Of course we must recognise some truths immediately as true. Knowledge has to begin somewhere or we d never get started. Where Our Ideas Come From Locke argued that there are no good reasons to believe in the sort of innate ideas or knowledge that the Rationalists believe in. So where does a priori knowledge come from? Well, ultimately from experience. We are born as blank slates. All our ideas come from two sources: sensation and reflection. Locke uses the word idea to refer to anything that is "before" the mind from a sensation to a complex idea, such as the ideas of space, time and what to do next Saturday. His account of the "genesis" of our stock of ideas is as follows As I open my eyes as a small child, I see the setting sun. More precisely, I have a particular visual experience of a yellow disc. It combines two simple ideas: a particular yellowness (colour) and a particular disc-ness (shape). 2. Let s focus on yellowness. By repeated exposure to particular yellow things butter, dandelions, etc. I will undergo many particular visual experiences part of which will be particular simple ideas of yellowness. Eventually, I will notice that these yellownesses are the same or similar. I gain the general idea of yellow. I can then think about yellow things "off-line" (when not stimulated by a yellow thing) and I grasp that there are different shades of yellow that are members of the same kind. 3. The yellowness is a simple idea because I cannot break it down into simpler ideas. An example of a complex idea is the idea of an apple. An apple has a certain texture, taste, colour and smell. As I look at an apple, sensation presents me with a complex idea that is composed of simple ideas, though I may not notice this until I start to think about things more deeply. 4. My mind can thus decomposee complex ideas from sensation into parts: an apple into a green colour, a sweet taste and a smooth texture. Going the other way, my mind can compose ideas to generate new ideas: unicorn from a horse and a horn. 5. As we observed above, my mind can generate general ideas from particular ideas. I experience a yellow sun, a yellow daffodil and a yellow lump of butter. I form the general idea of yellow by Page 46/109

47 Chapter 7: Classical Empiricism: Locke - What We Know abstraction. Abstraction is like filtering. It is not being in the sky or having petals or being spreadable on toast that makes something yellow. I abstract away from or filter out these irrelevant features from what I see to arrive at the idea of yellowness that represents what they have in common. Finally, my mind can compare ideas to get the idea of a relation. For example, if I have before my mind a light red and a dark red, I can gain the idea of being lighter than. 6. Our ideas of ordinary objects and their properties are simple or complex ideas arrived at through sensation. Reflection yields ideas of mental processes or operations: the ideas of perception, memory, discernment, comparison, compounding and abstraction: the tools we use to manipulate ideas so as to have a mental life and produce new ideas. We have called this sense of reflection introspection or inner sense. Locke thinks that animals perceive whereas vegetables do not but non-human animals do not have the tools of comparison and abstraction. They cannot generate general ideas and live in a world of particular ideas. What We Know Locke is an empiricist and so rejects all claims to know what exists and the nature of what exists on the basis of reason alone. At the same time, he holds that intuitive knowledge is the highest form of knowledge. For Locke, though, reason which delivers intuitions is not a special faculty with innate ideas that enable it to bypass the senses. Reason is a much simpler thing for Locke. Reason is our capacity to reflect upon the ideas we receive from the senses. So, I know intuitively that: The whole is greater than the part. Blue is not yellow. 2+2=4 The area of a circle with radius r is πr 2. This is a priori knowledge. But it is not knowledge of things that really exist. It is knowledge of ideas or concepts and the relations between them. There s one thing I can prove exists by intuition alone: me. I grasp the intuitive connection between thinking and existing, just as Descartes said. But whereas Descartes thought he was exercising pure reason, Locke rightly says he is merely using reflection or introspection. But Locke says that he proves very little: just that, in thinking, he exists. He cannot prove he existed five seconds ago as his memory is not a source of certainty. He cannot prove what he is as reflection doesn t reveal any more than conscious ideas. He may be an immaterial mind (as Descartes said) or a material mind (as Hobbes, another philosopher of the time said.) We need do more science and philosophy to find out. Pure reason cannot tell me. I also know intuitively what my thoughts or ideas are. I have intuitive knowledge of what s going on in my mind: what my ideas are. I can be certain that I have a green disc in my visual field. As with the Rationalists, the next grade of knowledge is demonstrative knowledge or knowledge by deductive proof. I know in this way that God exists. Locke has a proof that starts with intuitions and so has demonstrative knowledge of the conclusion. 1) I know I exist (by reflection: I am aware of my thoughts and that I exist). 2) Something must have created me as you can t get something from nothing. 3) My parents created me but then they must have been created 4) so, ultimately, there must have been a First Cause of everything 5) who must be an intelligent being to have created beings with intelligence. Locke s cosmological argument proves that God exists from Locke s experience of himself as a thinking being not from the concept of God. So, that God exists is not known a priori but a posteriori. Page 47/109

48 Chapter 7: Classical Empiricism: Locke - Knowledge and Necessity What about the world around me? I know a posteriori that there is an apple on my desk. Locke says that we can have knowledge of the things in the world that cause our ideas. He calls this sensitive knowledge. He is, however, extremely cautious about it for reasons we shall see in the next section. Whilst he may be certain that he experiences a green disc, to say it caused by an apple goes beyond our immediate experience and Locke is often found saying that when we talk about particular things and facts, we at best have highly probable beliefs. It is important to remember that Locke shared the common view of the time that the world was not as it seemed. Colours, smells, and so forth are ideas in the mind and not really in the things out there. The red in the tomato is really its molecular structure that causes the red sensation in me. Locke arrived at this view persuaded by the sorts of relatively and pleasure-pain arguments we have already seen. He accepted the view of reality as containing just matter in motion (atoms) as the best scientific picture. His beliefs here are a posteriori: justified by the experience he has of the world. Although different from Descartes, Locke is also a foundationalist. The foundations this time are not intuitions of the truth but our ideas from sensation and reflection. Whether this genuinely deserves to be called a foundation is something we ll question. Knowledge and Necessity We said in the previous chapter that philosophers are interested in necessary truths. But if necessary truths are known a priori by reason and Locke is an empiricist, what happens? With mathematical and geometric truths such as 2+2=4 and the area of a circle with radius r is πr 2, there s no problem. Numbers and circles aren t things but ideas. We grasp the concepts of 2 and circle from experience and then we notice necessary connections between the ideas. When we do science, we are dealing with things in reality. We know gold informally as a yellow, malleable metal. In reality it is a bunch of atoms. We don t know how the atoms produce the colour and the malleability. So, we don t really know what gold is. We have to observe and experiment to find out more about it. As we observed when discussing Leibniz, observation never gets us to necessity. We may find that every bit of gold tested so far is malleable but that at best entitles us to say probably the next bit will be malleable too. Real scientific knowledge, says Locke, is impossible. We have more or less justified a posteriori beliefs about the scientific world. The difference between circle and gold, says Locke is that we have a clear understanding of the former idea but not the latter. So, we can have a priori knowledge of the properties of circles because we are merely examining the concept. Our minds will only ever have an unclear idea of what gold is and so all our knowledge will be based on what we record from observation. 3 The same goes for all claims about reality. So long as we lack clear ideas of what s out there, we will at best have probable a posteriori beliefs about reality. It may be that there are necessary laws of nature (as Rationalists thought) but we ll simply never be in a position to know them. 4 Scepticism and The Veil of Perception Locke says that we have ideas derived from the senses. The ideas are the elements of thoughts and experiences. So, the world is presented to me through my ideas. In the same way, the world may be presented through photographs or a story that represent it. But this introduces a gap between representations and what they are representations of. The most detailed story may be a complete fabrication. A set of photographs can be doctored or completely faked. Just because they look as if they say that this is how things are, it doesn t mean that this is how things are. To check whether a photograph of (e.g.) Jim is a true likeness of him, we would need to compare Jim with the photograph. If Page 48/109

49 Chapter 7: Classical Empiricism: Locke - Summary we were to check one (apparent) photograph of him against another, we would run the risk of having two misleading photographs. The same is true even if we have a million photographs. The moral is simple. To check whether your representations are accurate, you need to compare them to what they represent. But this creates a huge problem for Empiricism. All I have are my ideas. I cannot get beyond my ideas to compare them to reality. It would be like trying to step outside of my head. So, I can t compare how the world is presented to me with how it really is. So, for all I know it could be radically different. As we have seen, Locke thought it was: the world does not contain colours, for example. But why stop there? Perhaps it doesn t contain matter perhaps it doesn t exist at all except in the mind of a demon or the Matrix. In short, our ideas constitute a veil between us and reality. They are supposed to bring reality right into the mind but instead cut us off! The Rationalist can solve the problem by saying that there is more than just experience. Descartes, for example, argued that we have an innate idea of God, who is a perfect being. A perfect being would not trick us into having experiences of a world that did not exist. So, we can know that there is a world out there that is in some ways as we see it. But Locke cannot appeal to any innate ideas. He s stuck. Not that he saw it this way. He expressed confidence that the candle or light of reason set up in all of us (by God he too was a believer) would not let us down. But he had no proof, as later philosophers were quick to point out. Summary There is no convincing evidence for innate ideas. We are born as blank slates. We build up general ideas from particular sensory ideas by (de)composition and abstraction. We have intuitive knowledge of our minds and sensitive knowledge of the world. All a priori knowledge is knowledge of concepts, not of real things. All proofs of what exist come from experience: me (by intuition), God (by demonstration), the apple on my desk (by observation). The scientific picture of the world shows it to possess only primary qualities which are not sensory. On this, Empiricists and Rationalists are agreed. By making our minds contain only ideas from experience, they cut us off from reality. Questions 1. We all have an idea of the sun and there is no reason to think it is innate. We all have it because the sun is something we re bound to sense at some point. What other common concepts can we explain in this way? 2. Are there any absolute moral or religious truths? 3. How would you explain how we get the following ideas? o o o o Trumpet King Fear Embarrassment 4. There s no problem of the veil of perception! I can check whether my idea of an apple represents it correctly by checking whether you have the same idea too. What s wrong with this way of thinking. 1 Note that this doesn t follow the exact order of exposition in the Essay and misses out much of the detail. Page 49/109

50 Chapter 7: Classical Empiricism: Locke - Questions 2 Locke s use of the word idea is notoriously slippery. It can mean a (i) sensation, such as the taste of coffee; (ii) a Humean idea, such as what I have when I recall the taste of coffee; (iii) a concept, such as coffee, thought of, as it were, without the taste; (iv) a thought such as coffee is nice. 3 If, like God, we had clear ideas of everything, then doing science would be like doing maths. We could deduce that gold would behave like that. Locke things we lack the senses to see into the inner workings of the world. So, in practice, we re limited to gaining probably beliefs on the basis of observation and experiment. But even if we had super senses, empiricism would still hold. Once again, all our ideas would come from experience and we d simply see how things work. So, all our knowledge of what exists and what things are like comes essentially or fundamentally from experience. Locke is still an empiricist. 4 We may have lots of evidence that (e.g.) water boils at 0 o C and this may in fact be a necessary truth. If we believe it to be a necessary truths, then we re right. But our evidence will only ever be repeated observation which does not entitle us to know that it is necessarily true; we can at best believe it to be so. To put it in a more formal way: Locke has no ontological problem with necessary truths about reality, just an epistemological one. Page 50/109

51 Chapter 8: Classical Empiricism: Berkeley on Locke - Introduction Chapter 8: Classical Empiricism: Berkeley on Locke Introduction Locke s philosophy caused a revolution. Leibniz was particularly annoyed by it. He thought Locke s picture of the mind was undignified. We have no special God-given power of reason any more. We are more like simple animals, dumbly sensing the world and making sense of it as best we can. In this chapter, we ll consider a couple of problems for Locke raised by Berkeley. Berkeley was a fellow Empiricist and so his criticisms were not in support of Rationalism but in support of a more extreme Berkeley would say genuine empiricism than Locke had provided. Locke s picture of general ideas is wrong, said Berkeley. You can t have a general picture of anything. Pictures are specific. Descartes, Locke and everyone else is wrong to think that the world is not as it seems. There is no such thing as matter with only primary qualities underneath what we can sense. The world is just what we can sense! Berkeley on Abstraction A particular idea is of a particular thing: a particular smell, a particular taste, a particular tomato. What makes us so intellectually powerful, however, is not our ability to combine simple particular ideas into more complex particular ideas, such as God, Paris or my great-aunt Alice. It is our power to generate general ideas. I have an idea of a tomato. Not any particular tomato but just tomatoes in general. Thanks to this, I can think thoughts such as I must by some tomatoes on my way home. It is not that there are some particular tomatoes I want to buy; any will do. Any account of how we have ideas has to explain how we have general ideas, therefore. The Rationalists argued that we have certain general innate ideas. They did not give much of a story about how we acquire general ideas from experience. (For not even the most ardent Rationalist would say that we have the concept of an ipod innately.) To the credit of the Empiricists, they took the problem head on. Locke s answer was abstraction. We form a general idea of triangle, for example, by seeing lots of triangles. isolating what they essentially have in common. ignoring the ways in which they accidentally differ. forming a picture of the essential not the accidental. Berkeley, also an Empiricist, criticised this analysis. We cannot picture a triangle in general. For a triangle in general is not equilateral or isosceles or scalene. These are types of triangle. But any triangle you draw will be either equilateral, isosceles or scalene. Similarly, the idea of a cat in general is the idea of a cat of no particular colour, size, shape or even number of legs. But you can t draw a cat with no colour, size, shape or a distinct number of legs! Of course, we do have the idea of a cat in general. The problem is that this idea can t be a picture of a cat. Nor can it be the sound of a cat or the smell of a cat. For any picture or sound or smell, we can now see, is a picture of a particular cat, the sound of a particular car or the smell of a particular cat. So, the obvious thing to say is that ideas cannot be pictures or sounds or smells (or tastes or feels). But the problem is that for the Empiricist, this is all we fundamentally have. The basic ingredients of thought are sensations and their copies. So, ultimately, all ideas must be combinations of images, sounds, smells, feels and tastes. Page 51/109

52 Chapter 8: Classical Empiricism: Berkeley on Locke - Berkeley and Idealism We have a contradiction here and a real problem for Empiricism. The later Empiricist Hume thought he had found a way out, as we shall see in the next chapter. Berkeley and Idealism Berkeley rejected the primary/secondary distinction and with it, the new picture of the world developed in the previous century. The picture is the following: The world is made up of matter with primary qualities, such as shape, size and motion. When we sense colours, tastes, and so on, these sensations in us are not copies of real colours, tastes, etc. in reality. Secondary qualities, such as red, are powers to produce sensations in us. The red in the tomato consists in its molecular structure. The red in me is a pure sensation. Remember that this picture is still pretty much the picture we have today. Reality as described by physics is very unlike reality as it is seems to us. Berkeley argued that this picture was wrong. He accepted that all the colours, tastes, and so on are really in us. They are just ideas or sensations. But whereas others said that outside the mind were the material things that cause these sensations, Berkeley said that there were no material things at all. Berkeley didn t simply think that there was no evidence for matter. He thought that the very concept of matter was incoherent. The tomato before me is nothing more than a collection of ideas: a collection of colours, tastes, feels and so forth. These ideas exist in the mind of God. So, the real world out there is really God s mind rather than something material God created. Let s work through this in a bit more detail. Berkeley uses the sorts of relativity and pleasure-pain arguments we ve seen already to prove that: The colour red or the taste of coffee is not a thing in an external object but an idea or sensation in a mind. Berkeley now reminds us that ideas can only exist in minds. An idea cannot exist like a pen or shoe, lying around, unthought of. Berkeley next extended these arguments by focusing on shape and solidity, two primary qualities we feel really are out there in things because of their material nature. Consider the shapes of an object. It varies as you move. And different people in different places will see different things. So there is really no shape the object has. Shape is an idea too. What does it mean to say something is solid? It means that it resists us when we push it. But resistance is something we feel. So, to say something is solid is just like saying it is red: we get a certain sensation. Berkeley therefore drives us to the following conclusion: Things have colours and tastes and smells and shapes and sizes and solidity. All of these are not in things but are ideas. But once we have taken away all of the colours and tastes (etc.) and size, shape and solidity from a thing, there is nothing left! A thing is therefore nothing more than a collection of ideas. But if ideas need minds to exist in, then we have a problem. There are places in this room that no-one is thinking about or sensing. Do they not exist? Surely not! Does my office cease to exist when I turn the lights out and close the door? This would be absurd. So, Berkeley draws his final conclusion: Page 52/109

53 Chapter 8: Classical Empiricism: Berkeley on Locke - Summary There is a God thinks of everything. The world is a collection of his ideas that our limited minds share in. We arrive at the surprising conclusion that the apple on my desk is a collection of ideas in the mind of God! We want to protest that this is absurd. We want to say that even if the colours and so on are in the mind, there is a material thing out there whose apparent shape of course differs from its real shape. But Berkeley will ask us to say what this real shape is when all we see are changing shapes. If we say that the real shape is unknowable, Berkeley will say that there is no good reason to believe in it. He will also ask us to at least say what we mean by real shape even if we can t identify it. But to describe a shape is to describe the way something looks. A look is an idea in the mind. So, we are led back to the view that everything is in the mind. Everyone found Berkeley s views mad and they will no doubt strike you as mad too. But it is important not to dismiss him. Hume and Kant were both sensitive to the main point he was making: The world is known to us through the senses: the way it looks, feels, and so on. Of what lies beyond the senses we cannot form even a clear idea. So, we have no reason to believe in anything beyond it. Summary There is no convincing evidence for innate ideas. We are born as blank slates. We build up general ideas from particular sensory ideas by (de)composition and abstraction. We gain knowledge by discovering (necessary) connections between our general ideas (concepts) which we gain from experience. The scientific picture of the world shows it to possess only primary qualities which are not sensory. On this, (some) Empiricists and Rationalists are agreed. Locke is criticised by Berkeley in two ways: first, that general ideas can t be sensory; and, second, that we cannot even understand primary qualities. A proper Empiricism must eliminate the distinction. Questions 1) We have ideas of God, infinity and good. Can we explain how these are built up from experiences and simpler ideas? Or is Leibniz right: no amount of experience could help? 2) A general picture of a cat is not some cat-monster but a picture of a paradigm or typical cat. We identify cats as cats because they look like the paradigm. What problems are this with this view? o Hint: try to define the paradigm cat. o Hint: (harder) how must other cats resemble the paradigm cat? 3) Berkeley says that the shapes of things change, so there is no such thing as the shape. What about motion? When a car drives past, is there an absolute motion it has? 4) We all have a concept of time. Is this a concept of the way something looks or feels? How do we know that time is passing? Page 53/109

54 Chapter 9: Classical Empiricism: Hume - Introduction Chapter 9: Classical Empiricism: Hume Introduction Classical Empiricism s greatest proponent was the philosopher David Hume ( ). Hume took the view that all knowledge begins and hence must end with the senses to its logical conclusion. All my knowledge of the world comes ultimately in the form of ideas that are sensory colours, smells, tastes, and so on. We cannot claim to know about what, if anything, lies beyond. Hume famously rejected the old way of doing things, saying that the old books of metaphysics that talk about the reality only reason grasps should be consigned to the flames. He was truly radical. All substantial knowledge is of a posteriori truths. A priori knowledge is of mere relations of ideas logical and definitional truths. We think of the world as containing substances and selves and we think that cause leads to effect. But this is just how we make sense of experiences. We don t detect these things in reality; we project them onto reality. In this chapter, we will look at Hume s radical claims. We will say the following: Like Locke, we build up our complex ideas from simple ones by sensation and reflection. All knowledge can be divided by Hume s fork into the a priori (trivial) and a posteriori (substantial). This coincides with a new distinction: the analytic and the synthetic. We can be certain of (i) a priori analytic truths and (ii) truths about our thoughts gained through introspection. Substance is an invention As is cause and effect. Where Our Ideas Come From Ideas and Impressions Hume ( ) followed Locke ( ) in believing that we are born as blank slates with innate capacities for learning. Locke argued that our senses deliver us ideas that are the materials of all thought. An idea is a sensory item. A visual idea of a tomato is just an image of a tomato. Hume essentially agreed but made an important division. Hume translated Locke s rather general word idea as perception. He said that we have perceptions that fall into two types: impressions from ideas. Our senses deliver us forceful (involuntary) and vivid experiences: impressions. When we recall an experience it is never as vivid. It has become an idea a faint copy of the original. Hume argued that all ideas begin with impressions. An impression is a perceived patch of colour, a sound, a smell. Other names for this sort of thing are sensation or sense-datum. What matters is that they are the things in our experience we are immediately or directly aware of. To be immediately or directly aware means that there is no inference. For example, I might see a leaf and not recognise its shape as the leaf of a beech tree. If I see the leaf as the leaf of a beech tree, then I infer that. I go beyond the sheer appearance thanks to my knowledge. The simple impression of the shape that the novice and expert share is the impression or sense-datum. Another commonly-encountered way of expressing this idea is that these things are simply given to us in Page 54/109

55 Chapter 9: Classical Empiricism: Hume - Where Our Ideas Come From experience. We don t need to think about what they are. They simply announce themselves in all their glory to our consciousness. The word datum in sense-datum just means given. So a sense-datum is something sensory given to us in consciousness. Our mind makes copies of them as ideas. Our mind can combine these ideas to create new and ever more complex ideas. When we use our imagination, we are usually limited to fabricating ideas as our imaginative powers create experiences as faint as memories. When we dream or hallucinate, however, we have impressions, albeit ones that do not correspond to reality. Perceptions ideas and impressions are the products of sensation: from our eyes, noses, ears and so forth. Along with them, we have impressions and ideas from inwardly sensing or reflection. I may have the impression of fear when walking through the Wood of Much Peril a vivid experience and an idea of fear when I think about fear. My impression is arrived at through my capacity to monitor internally the state of my body and mind. The Copy Principle Ideas are the materials of thought. Ideas are essentially sensory. Born as a blank slate, I can only think with what the senses deliver me. When I think about tomatoes, I must be thinking of an image or taste or feel. Hume argued that all ideas are ultimately copies of impressions, though they may not be direct copies. For example, I have an idea of a unicorn but I may never have had an impression of one. (I cannot of course have an impression of a real unicorn but I could have a real impression of a unicorn statue.) I cannot directly experience God or omnipotence or omnibenevolence but I can have impressions that lead to ideas that ultimately lead to them. For example, I might have the idea of wisdom from reflecting on the fact that I know certain things, the idea of one thing being greater than another on the basis of having seen one tree bigger than another, one man running faster than another and the idea of a limit or boundary likewise from seeing physical limits and boundaries. From this, I could concoct the idea of being maximally powerful. Hume s Copy Principle is then that every idea must originate in impressions. It is the great mistake of philosophers, says Hume, to think that they can think about things that go beyond the senses. They cannot. The very suggestion is as incoherent as that of speaking without a language. Proving The Copy Principle Hume thought the Copy Principle to be so obvious as to not be worth proving in any great detail. First, he simply challenged anyone who denied to prove him wrong: Those who would assert, that this position is not universally true nor without exception, have only one, and that an easy method of refuting it; by producing that idea, which, in their opinion, is not derived from [experience]. Enquiry, Section II: On the ORIGIN of IDEAS - 6 Is this fair? Can I prove that there are no unicorns by simply saying, If there are, then you must show me one! It is true that if you did, I would be proven wrong. But if you don t, perhaps the better thing to say is that it is unproven. More constructively, we might find ideas that have no basis in experience. What about my idea of -2? Or π? Or even God? Despite what Hume says, do I really have a clear idea of a being outside of space and time? (Hume might well have replied that if I don t have or can t have such an idea, then so much the worse for God.) Hume then gave a second line of argument: If it happen, from a defect of the organ, that a man is not susceptible of any species of sensation, we always find, that he is as little susceptible of the correspondent ideas. A blind man Page 55/109

56 Chapter 9: Classical Empiricism: Hume - Hume's Fork can form no notion of colours; a deaf man of sounds. Restore either of them that sense, in which he is deficient; by opening this new inlet for his sensations, you also open an inlet for the ideas; and he finds no difficulty in conceiving these objects. The case is the same, if the object, proper for exciting any sensation, has never been applied to the organ. A LAPLANDER or NEGROE has no notion of the relish of wine. A man of mild manners can form no idea of inveterate revenge or cruelty; nor can a selfish heart easily conceive the heights of friendship and generosity. It is readily allowed, that other beings may possess many senses of which we can have no conception. Enquiry, Section II: On the ORIGIN of IDEAS - 7 A blind man has no idea of red because he has no visual sense. But if the idea of red were innate, then it would surely be possible to have the idea without experience. Similarly, says Hume, you cannot form ideas of foodstuffs or emotions unless you ve experienced them themselves. Association Hume was extremely impressed by the scientist Newton. Newton had famously explained the motion of everything from an orbiting planet to a thrown ball in terms of a few simple laws. Hume hoped to do the same for the mind. He thought that our minds received impressions which they copied into ideas which could then be associated with one another by a kind of mental gravity. One idea leads to another and to another a train of thought because we form associations between these ideas. The idea of fish and chips, for example, might lead to an idea of vinegar. Hume's Fork Hume made a very bold and important claim, which it is worth quoting in full: ALL the objects of human reason or enquiry may naturally be divided into two kinds, to wit, Relations of Ideas, and Matters of Fact. Of the first kind are the sciences of Geometry, Algebra, and Arithmetic; and in short, every affirmation which is either intuitively or demonstratively certain. That the square of the hypotenuse is equal to the square of the two sides, is a proposition which expresses a relation between these figures. That three times five is equal to the half of thirty, expresses a relation between these numbers. Propositions of this kind are discoverable by the mere operation of thought, without dependence on what is anywhere existent in the universe. Though there never were a circle or triangle in nature, the truths demonstrated by Euclid would for ever retain their certainty and evidence. Matters of fact, which are the second objects of human reason, are not ascertained in the same manner; nor is our evidence of their truth, however great, of a like nature with the foregoing. The contrary of every matter of fact is still possible; because it can never imply a contradiction, and is conceived by the mind with the same facility and distinctness, as if ever so conformable to reality. That the sun will not rise to-morrow is no less intelligible a proposition, and implies no more contradiction than the affirmation, that it will rise. We should in vain, therefore, attempt to demonstrate its falsehood. Were it demonstratively false, it would imply a contradiction, and could never be distinctly conceived by the mind.(enquiry, Section IV, Pt. I) Hume says that all that we may claim to know can be divided into two categories: relations of ideas (analytic) and matters of fact (synthetic): In relations of ideas we find claims like 2+2=4 and a square has four sides. These we can know to be true with absolute certainty simply because we understand the connections between the ideas. The truths are necessary and we know them through reason alone a priori. In matters of fact, we find claims like the sun is shining and tigers exist. These truths are known on the basis of experience and are a posteriori. They are contingent truths. Kant will re-label Hume s fork as the division between the analytic and the synthetic. Page 56/109

57 Chapter 9: Classical Empiricism: Hume - What can we know about reality? Like Locke, Hume says the following about knowledge. A priori knowledge is not of real things but of concepts or ideas and the connections between them: mathematical and geometric truths along with what we shall call analytic truths or tautologies mere truths of definition like a bachelor is an unmarried man. The existence and nature of what is real out there is known on the basis of sensory experience, not reason, and so is a posteriori. We know by reflection (inner sense, introspection) what our thoughts (ideas, impressions) are. What can we know about reality? Locke said that reality was not as it seemed. The colour of red is not in the tomato but in us: what is in the tomato that we denote by red is the power to produce the sensation in us. The world contains matter with just primary qualities which cause all our sensations. Hume pressed the question of whether we can with confidence know even this much about reality and concluded we could not. We shall examine his reasoning in a number of stages. Here is what we shall say in a summary form. 1) We cannot know what exists or what it is like a priori. You cannot deduce anything about the world from our ideas of it. Existential claims and laws of nature can be denied without contradiction. 2) Our knowledge of the world is a posteriori and based on our knowledge of cause and effect. 3) But we do not see cause and effect in reality. We merely feel as if one thing must lead to another. Causation is constant conjunction with the impression of necessity. 4) We form our beliefs in cause and effect inductively. 5) But there s no rational basis for induction. 6) So, there s no rational basis for believing o in a world of things that cause our impressions o in necessary laws of nature over and above our particular experiences of the world. 7) We simply believe these things because we are built this way. Deduction and Induction The first step on the journey requires us to make a distinction between two types of argument: deductive and inductive. We gain knowledge by constructing proofs, both in the armchair and in the laboratory. A proof is also known as an argument. It starts with premises or assumptions and ends with a conclusion. The premises are what you take to be true. The conclusion is what you discover to be true. Philosophers distinguish (at least) two types of argument: deductive and inductive. The distinction is important. A deductive argument is one whose premises guarantee the truth of their conclusion. So, if the premises are true, the conclusion must be too. Such an argument is also said to be deductively valid. An argument that is presented as deductively valid but isn t is deductively invalid. For example: Deductively valid All badgers are quadrupeds. All quadrupeds dance. Deductively invalid All badgers are quadrupeds. Some quadrupeds dance. Page 57/109

58 Chapter 9: Classical Empiricism: Hume - Deduction and Induction All badgers dance. All badgers dance. It is vital to observe that what matters is the relation between the premises and the conclusion. We want to know whether if the premises are true, the conclusion follows. Whether the premises are in fact true is another matter entirely. Indeed, in the argument above, it is patently false that all quadrupeds dance. If the premises and conclusion of a valid argument are true, we say that the argument is sound; if not, unsound. Deductively valid & unsound Deductively valid and sound All badgers are quadrupeds. All quadrupeds dance. All badgers dance. No prime number > 2 is even. 8 is even. 8 > 2 8 is not prime. Traditionally, inductive arguments take the following form something has been observed to be true on a large number of particular occasions and therefore it is true in general. For example: All 1000 bits of gold tested so far conducted electricity gold conducts electricity. All 1000 tigers seen so far have had stripes all tigers have stripes. We might put the general principle as follows: If X with Y have occurred together n times, where n is very big, then it is true that X and Y occur together. Deductive arguments get the gold medal. Assuming you are certain of the truth of the premises, you can be certain of the truth of the conclusion. Inductive arguments get the silver medal. Just because you ve seen 1000 tigers, you can t guarantee that the 1001 th tiger will be striped. (It was once believed all swans were white on the basis of countless observations. Yet black swans exist in great numbers. They just happened to be in Australia, which most people didn t know about until relatively recently.) The best we can say that it will probably be striped. The more striped tigers we see, the more probable the truth of the general claim: 1000 tigers seen probable tigers seen more probable. So, we can say: A deductive argument is one where the truth of the premises guarantees the truth of the conclusion. o In a deductive argument, the premises necessitate the conclusion the conclusion must follow from the premises. An inductive argument is one where the truth of the premises makes the truth of the conclusion probable. o In an inductive argument, the premises do not necessitate the conclusion the conclusion need not follow from the premises. Page 58/109

59 Chapter 9: Classical Empiricism: Hume - A Priori Knowledge of Existence and Causes A Priori Knowledge of Existence and Causes As we know, Rationalists would like to get a priori knowledge of reality by deducing new truths from certainties known by intuition. This would give us gold-standard knowledge. But Hume says: Any claim of the form X exists can be denied without contradiction. Clearly, I feel I exist but it is perfectly conceivable that I do not. The same goes for everything else around me. The same also goes for God. Contrary to Descartes, Hume (like Locke) rejects the ontological argument. The concept or idea of X merely describes what it is to be X. Someone could tell us a story about badgers and unicorns and artichokes and angels and we could understand it perfectly without knowing which things exist and which don t. It is one thing for the idea of X to make sense and quite another for X to exist. To determine the latter we need to explore reality to see if anything fits the idea of X. Idea X X makes sense? Do any X exist? Round square NO NO Unicorn YES NO Badger YES YES Next, Hume says that we cannot have a priori knowledge of causes and effects. Now, what is going on when we say X caused Y? Well, what we think is this: 1) X happened before Y. 2) X happened near Y. 3) X necessitated Y. Take the match example again: 1) X happened before Y. Had match burst into flames before I had struck it, we wouldn t say I caused it to ignite. A cause must come before its effect. 2) X happened near Y. Had I struck the match and a tree in the garden burst into flames, we would not I say I caused it. This idea goes back a long way and is known as the idea that there is no action at a distance. 3) X necessitated Y. As I just typed that word, a train sounded its horn. But that was just a coincidence. I didn t cause it. When we speak of a cause, we say that something specific must happen next. Hume accepts 1 and 2 and focuses on 3. If the cause necessitates its effect, then that is to say that the effect logically follows from the cause or that we can deduce the effect from the cause. This is just as the Rationalist would like it: 1) Cause: I strike the match 2) Law: struck matches ignite 3) Therefore: Effect: the match will ignite But Hume says that there is no logical connection between a cause and effect. Why? Because it is never contradictory to deny that the effect will follow the cause. They are separate existences as he puts it. Suppose again that I strike the match. It is conceivable that the match stays dry. the match turns into ice. the match doubles in size. Anything logically could follow. So, there is no chance of deducing anything and no a priori knowledge of causes and effects. What, then, is happening when we feel that causes necessitate effects? Hume now Page 59/109

60 Chapter 9: Classical Empiricism: Hume - The Problem of Induction presents his famous analysis. In the past, I have seen matches being struck and then a flame appearing. I have seen this so many times that the mere sight impression of the struck match makes me expect that I will have an impression of a flame. As Hume puts it, my idea of a flame is enlivened: even if I don t see the flame, in my mind I irresistibly have the idea of one. I am like a Pavlovian dog. I simply see one thing then another as unconnected but my mind eventually makes me expect one thing then another. Causation is all psychological all in the mind. The necessity I see is not in the world but is an impression in me that is produced by reflection on my past experiences of match-then-flame. I simply feel that the flame must follow. We may therefore compare a Rationalist analysis with Hume s analysis as follows: The dropped match (cause) caused the fire (effect). Rationalist Hume We have observed the following: Dropped matches are followed shortly after in time by fires. Dropped matches and fires occur next to one another. This leads us to conclude that the dropped matches cause the fire. That is: we discover that it is a law of nature that dropped matches cause fires. This is how reality out there is. It is a necessary truth. It is something we can discover by reason. Causation is a real relation between events in the world. We have observed the following: Dropped matches are followed shortly in time by fires. Dropped matches and fires occur next one another. after After sufficiently many observations, we come to associate dropped-match events with fireevents. This association invokes a feeling of expectation that we call necessity. We have not discovered how reality is out there. We have not discovered a necessary truth. We have merely discovered an association between ideas in our minds. It is a contingent truth that dropped matches cause fires: it could be different tomorrow. The association is discovered by experience, not reason. Causation is nothing more than regularity with a distinctive impression, the feeling of necessity. to The Problem of Induction So, all our knowledge of cause and effect is built up by careful observation of nature. We don t see it in the world but come to believe that one thing will follow another. There is no logical connection between cause and effect. But just because we can t prove by deduction that cause will follow effect, we can prove it by induction, right? After all, this is how we live our lives! We see X then Y a few times, jump to the generalisation, and use it ever after. No-one stops each day to ask whether the door handle will dissolve into sugar when they touch it. It has remained solid up to now and so is bound to stay that way. Hume now argues that there are no rational grounds for inductive reasoning. We reason inductively because that is simply how our minds are built, not because it is rational. How would we prove that induction is a rational way of acquiring beliefs? Well, the best way to prove something is by deduction. So, we would have to say that: if you use induction to prove a general truth, then it must be true. More fully: Page 60/109

61 Chapter 9: Classical Empiricism: Hume - The External World If (for example) you ve seen 1,000,000 tigers and concluded that all tigers are striped, then this must be true. But we know that this won t work. Induction can at best establish probable truths. Even if we ve seen a million striped tigers, that doesn t prove that all tigers must be striped. But nor can we prove it to be true inductively. For that would be to use induction reasoning to prove the validity of inductive reason, which we would be circular. This is the tricky bit, so let s work through it more slowly. The principle of induction works only if we assume that nature is uniform: that the laws of nature won t change. For just suppose that the universe is built so that in 2100, gravity becomes a repulsive rather than attractive force. This would mean that the law of nature that massy objects fall to earth would not be true any more, and hence not a law of nature after all. So, can we prove that assumption and prove that this won t happen? Well, all we can do is say that all our evidence is that nature is uniform. What does such evidence look like? So far, all tigers seen have been striped. So far, all things (of a certain mass) have fallen to Earth. So far, all human hearts have four chambers. and so on so, nature has been uniform in the past. So, nature will continue to be uniform nature just is uniform. But look carefully at what we re doing. We are reasoning inductively. We are saying that across many periods in the past (up to the present day), nature has been uniform; so nature is uniform. So, we are supposing inductive reasoning is safe to prove that nature is uniform; but we need to prove nature is uniform in order to guarantee that induction works. So we are going in a circle. If the principle of induction was safe, we would have a rational basis for establishing laws of nature on the basis of experiences. Since it cannot be proved to be safe, we have no rational basis at all for trusting it. Yet we do. Hume argues that our minds are simply built to respect the principle. It is like an intellectual reflex. Once again, reason is shown to be of little power and use in telling us about the world. The External World We cannot prove that there is a world beyond our ideas. I have an idea of a tomato that I take to be caused by a tomato. But this cannot be established by deduction or induction. I simply cannot help but feel that the world contains substances. As we know, Descartes argued that the senses are unable to explain our knowledge that we live in a world of objects. For the senses present us with changing impressions; and yet we know that there are stable things amongst the change. We must have the innate idea of a thing a three-dimensional bit of space for us to make sense of the world. Hume disagreed. We enter the world with no such idea and we do experience a world of constant change. We do not know that there is stability. Over time, our minds impose stability on it to make the world comprehensible. Suppose I have a book on my desk. As I move my head, I see different shapes. It would be quite possible to conclude that there is, at each moment, a different two-dimensional entity I am experiencing. But it makes life simpler to treat these different appearances as features of the same thing. Otherwise, my world would be too complex as I would be seeing new things at every moment. Similarly, if I close my eyes and open them again, the world looks the same. I could be seeing two different things Page 61/109

62 Chapter 9: Classical Empiricism: Hume - The Internal World two unconnected books but it is surely simpler to suppose that something can exist when I do not see it. This raises an obvious question that Descartes saw. How do we know which impressions to link together into things? Why say that the wax is the same wax when all the sensory properties have changed? Hume would reply that the change was gradual and predictable. That is, we saw a slow succession of similarlooking things in roughly the same space. The change was predictable in the sense that it can be and has been repeated on numerous occasions. In the same way, what makes me treat the book as a thing and not the book-and-desk is that as I move my head or interact with the book, the perceptions I have hang together in a systematic way. I can separate the book from the desk and take the book away. I can t take half the book away (without destroying it, of course). Finally, what about Descartes point that imagination is insufficient to give us the idea of an object because an object can appear in infinitely many ways but we don t have to think of the infinitely many ways an object can appear (indeed, we can t our minds are finite) to understand what an object is? Hume would agree that we can t imagine the infinitely many ways an object can appear. But we don t need to. We need to grasp the few general principles that tell us how to determine which impression is associated with which to make sense of the world. As we have seen, these might look as follows: When your impressions change (e.g. when you move your head a fraction), identify those impressions most similar to the ones you saw: link these together. (e.g. moving around a book). If you move forward, certain impressions will uniformly increase in size: these can be linked together. (e.g. consider yourself moving towards a coffee cup). But what is the thing underneath the changing impressions? Hume said that there is no such hidden thing we can know about. We can only know about changing impressions. Talk of things is talk of linked impressions. A thing is an idea we generate to simplify the impression we have. So, once again, Hume characteristically turns philosophy on its head. No more are we investigating the things in reality. We are not entitled even to talk about reality containing things. The Internal World I can t know anything about the world beyond my senses. But surely I can know about the world inside my mind! Hume did not question our certainty of what we are experiencing. I can be certain that I am sensing red, for example. But I cannot have any knowledge of myself as a substance. Hume s thinking here parallels his thinking about substances. When I look at a tomato, all I really have are sensations (impressions). As I move around it, they change. When I close my eyes and open them, I have new sensations. I simplify things by saying that there is a real tomato out there that is the cause of my perceptions. When I look at myself, all I really have are impressions and ideas: thoughts, feelings, emotions and so forth. They change over time. There are periods of time when I do not have any sensations (I am asleep). I simplify things by saying that all these impression and ideas come from an inner self. But it is just as much of a fiction. Hume s view is quite radical. I can t conclude I exist. All I can say is that there are thoughts and feelings that I naturally feel are in some way part of a unified thing: me. Big Ideas Deflated The Rationalist says that some ideas must be innate because they could not be built up from experience: Page 62/109

63 Chapter 9: Classical Empiricism: Hume - Summary God: God is beyond experience as an infinite being. Substance: must lie beyond the senses (Descartes and the wax) Self: can t be observed but must exist as I think. (Descartes and the cogito) Necessity: the senses present us with how things are, not how things must be. We can t grasp necessary truths and we can t grasp the very idea of necessity. Circle: we cannot see a perfect circle. Beauty, goodness: we cannot sense anything in common between beautiful things and good acts. Hume says all can be deflated: God: we build up an idea of an infinite being from extrapolation from a finite being. If you think this doesn t equal the idea of God, so much the worse for your idea! I say that you don t have a clear idea after all! Substance: no rational (deductive or inductive) basis for believing it just a natural reflex. Self: can only observe ideas/impressions, not a self behind them. Necessity: no more than a feeling derived from reflection. Circle: an idea derived from experience. We have not dealt explicitly with the last one, so let us spend a bit more time. Hume argues that our ideas of beauty and goodness come from reflection on impressions we have. Some things make me feel a certain way and I call this impression beauty. I mistakenly think it is something in things in the same way that people mistakenly think redness is in the tomato. Similarly, when I say that I see goodness in an act, I am merely feeling a certain way that I come to name good. Summary All our ideas come from experience via impressions. Any knowledge about reality what exists and what it is like is a posteriori knowledge: justified by experience. We can have a priori knowledge but of the connections between ideas. A priori knowledge is of relations of ideas and such truths are necessary. A posteriori knowledge is of matters of fact and such truths are contingent. o There is no third category: Kant will disagree. Hume argues that there are no substantial necessary truths laws of nature to be known. Instead, all we can know are how the world appears at particular times. We cannot but help forming generalisations by induction but they are contingent general truths and there is not even any rational justification for them. We do not find cause and effect in the world it is something our mind imposes on the world. Our knowledge is limited to what the senses tell us: it is pointless trying to go beyond. We cannot even talk of things. The traditional conception of philosophy as the discipline which aims to uncover the necessary truths about reality a priori is dead. Instead, we must be content with the much lesser aim of amassing particular facts about how it seems and constructing tentative generalisations and concepts about what it is like. Page 63/109

64 Chapter 9: Classical Empiricism: Hume - Questions Questions 1. Which claims express relations of ideas (=analytic) and which matters of fact (=synthetic)? The Pope is Catholic. April is the month after May. Chocolate is sold in bars. Carrots are orange. Gold is an element. 2. Which arguments are deductive and which inductive? 17 is a prime number. Therefore, it cannot be divided by 4. Every horse we ve seen has four legs. Therefore, horses have four legs. It has been cooler in January than in June every year since records began. Therefore, June is hotter than January. If it is Tuesday, Jim will be working in Paris. It is Tuesday. So, Jim will be working in Paris. The medicine cured everybody it was tested on with illness X. Therefore, the medicine cures illness X. 3. Can we have ideas without having had the impressions first? Can you imagine, for example, the taste of bacon-flavoured ice-cream? 4. Is an idea of pain a faint copy? When you think of pain or recall past pains, do they still hurt? 5. Are you always sure what is going on your mind? Have you ever o o o o found the word you want to say elusively on the tip of your tongue? felt annoyed but without knowing why? been uncertain whether you have a pain? walked into a room and suddenly realised you don t know you did? Page 64/109

65 Chapter 10: Problems With Classical Empiricism - Introduction Chapter 10: Problems With Classical Empiricism Introduction Hume took Empiricism to extremes. The general complaint is that he takes things too far. By telling us we can t know anything beyond our impressions of the world, he cuts us off from it. This is the sceptical/solipsistic problem. We shall also question whether raw experience is powerful enough to create the ideas we have. In this chapter, we will look at criticisms of Hume and empiricism in general. They will fall into four categories: 1. The issue of innateness. 2. Problems building up complex ideas. 3. Problems with simple ideas. 4. Scepticism and being cut off. 1. Innateness Locke and Hume both shared the view that there are no innate ideas. Leibniz, a Rationalist, criticised Locke for misunderstanding what is meant by an innate idea. It is not something fully formed at birth. We have innate abilities to develop certain ideas. Leibniz explains this with the famous analogy of Hercules and the block of marble. If the soul (i.e. mind) were like an empty page, then truths would be in us in the way that the shape of Hercules is in an uncarved piece of marble that is entirely neutral as to whether it takes Hercules shape or some other. Contrast that piece of marble with one that is veined in a way that marks out the shape of Hercules rather than other shapes. This latter block would be more inclined to take that shape than the former would, and Hercules would be in a way innate in it, even though it would take a lot of work to expose the veins and to polish them into clarity. This is how ideas and truths are innate in us - as inclinations, dispositions, tendencies, or natural potentialities, and not as actual thinkings, though these potentialities are always accompanied by certain actual thinkings, often insensible ones, which correspond to them. (Leibniz, Nouveaux Essais) Experience is like the chisel of the sculptor. It brings out the knowledge buried within us. With no experience or the wrong sort of experience the truths remain hidden. Innate ideas are therefore innate capacities or dispositions in the mind. A disposition is best explained by example. A sugar-cube has the disposition of dissolving in hot water. If you put it in hot water, then it will dissolve. Of course, it may never be put in hot water. But it retains the disposition nonetheless. In the same way, my mind is built in such a way that, under the right conditions, it will form certain ideas. Will this do? Locke would say no; as would Hume. The problem is that it makes the criterion for being innate too weak. Leibniz gives up the idea that an innate truth is something actually known but something we could know. What we have, therefore, are innate capacities to learn. But the empiricist will agree with this. We have minds that are designed to know things to process the data from the senses, to form particular ideas, to compare them and form abstract, general ideas and to put these ideas together into thoughts. The Empiricist is not saying that our minds are so blank that there is nothing at all in them. If our minds were that blank, they d stay that blank! So should we conclude that Locke and Leibniz are essentially in agreement? We all have something innate, but not fully-formed ideas? No. The issue becomes the following one: Page 65/109

66 Chapter 10: Problems With Classical Empiricism - 1. Innateness Leibniz says that experience triggers or releases ideas in the mind that go beyond sensory experience. Locke and Hume says that experience gives the data from which ideas are created, so that no idea can go beyond sensory experience. The real test, therefore, is whether there are any ideas we have that can t be explained as being built up out of sensory experiences. The Rationalists throw their favourites up at this point: God Numbers/shapes Self Substance Necessity Locke and Hume took the challenge seriously and tried to explain or explain away all these ideas as derived from impression from sensation or reflection with the simple tools of mixing (adding/subtracting) ideas to make new ones, abstraction (Locke) and association (Hume). In the next section we will look at other examples of difficult ideas. Here, however, we will consider some modern evidence. Chomsky and Rationalism How do we learn our mother tongue? It was once thought that we learned our language in the way the Empiricists suggested we learn everything. We start with nothing except powerful capacities to learn. We hear people say words and point to things. Like Pavlovian dogs associating bells with food, we associate table with tables, shoe with shoes, badger with badger, and so on. Having learned simple words and simple grammatical constructions. Don t children start with little sentences like me want toy? Over time, we work our way to more complex words and more complex constructions: use of tenses, relative clauses, counterfactual constructions and so on. In 1959, the linguist Noam Chomsky wrote a celebrated review of a book called Verbal Behaviour by B. F. Skinner. He argued that all human behaviour, language included, could be explained in something like the manner just specified. Chomsky s review took the book apart. It was the end of the blank slate theory of language learning and the idea that we have innate knowledge of the underlying grammar of natural languages. Chomsky made lots of points, some technical ones that are hard to understand and some relatively easy. Here is the main, relatively easy argument: the poverty of stimulus argument. 1) We learn language very quickly as children. 2) Languages are fiendishly complex. 3) We do not have anything like enough data to do this in a methodical, scientific way. 4) Therefore, we must be born with some knowledge of language. Think about what is involved in learning a language. You do not simply repeat what you hear. You invent new sentences. You have to learn the right order to put words in. The last sentence was a relatively short sentence of 10 words. There are 10! possible ways of arranging the words, which is 3,628,800 of which only 1 is correct. So, looking at it in the other direction, when you hear a sentence, you have to work out the unique way in which someone has put the words together so that you can exploit the same structure to generate a different sentence: e.g. John went to the shops Steve drove to a cinema. You do not have time to test, in the manner of a scientist, over three million permutations by uttering them in turn and seeing which one your mother praises you for using! Page 66/109

67 Chapter 10: Problems With Classical Empiricism - 1. Innateness Don t think that the rules you have to learn are simple either. Take the sentence The badger is in the garden. If you want to make a question out of it, what do you do? Easy, you might think: move the verb to the front of the sentence The badger [is] in the garden [Is] the badger in the garden? But now consider the sentence: the cat that is hungry is in the garden. If you apply the rule, you get the wrong result: The badger that [is] hungry is in the garden *[Is] the badger that hungry is in the garden? You have to move the final verb: The badger that is hungry [is] in the garden *[Is] the badger that is hungry in the garden? As you can see, in our original sentence the first verb is the final verb, so this works for both. But consider how this doesn t work with the following sentence: you need to move the middle verb! The badger that is hungry is in the garden that is owned by Jim o * [Is] the badger that is hungry is in the garden that owned by Jim? nonsense. o [Is] the badger that is hungry in the garden that is owned by Jim? correct. And it isn t, as you might expect that simple. As an introductory course in linguistics will show you very quickly, you have a lot of extremely complex rules in your head that you manipulate with ease to produce coherent English. Another simple point to make is that when we are young, we hear many interrogatives ( Would you like to play? ) and imperatives ( Don t do that! ) and yet most of the sentences we utter are declaratives ( I am tired ). Chomsky argued that we are all born with our minds programmed with the rules of what he calls universal grammar. All natural languages, he alleges, are ultimately born out of a single set of rules. When we are young, we notice key features of the language(s) around us and these determine the actual grammar of the language(s) we speak. For example, English is an SVO language. The Subject precedes the Verb which precedes the Object (in ordinary simple declarative sentences). For example: [The boy] S [loves] V [the girl] O A language like Latin (classical Latin, at least) is SOV: [Puer] S [puellam] O [amat] V There are four other possibilities: OSV, OVS, VSO and VOS. All are realised A child would need to pick up on which order the subject, object and verb occur in. S O V Latin Puer puellam amat The boy loves the girl [puer] S [puellam] O [amat] V 45% [(the) boy] S [(the) girl] O [likes] V Page 67/109

68 Chapter 10: Problems With Classical Empiricism - 2. Complex ideas S V O V S O V O S O V S O S V Polish Welsh Malagasy Hixkaryana(Carib) (Guarijio, Tapirapé. Klingon.) Nadëb (Maku) (Xavante, Jamamadi.) Borsuk spostrzegł jabłko The badger noticed the apple [borsuk] S [spostrzegł] V [jabłko] O 42% [(the) badger] S [noticed] V [apple] O Darllenais I y llyfr I read the book [darllenais] V [I] S [y] [llyfr] O 9% [read] V [I] S [the] [book] O Manasa ni lamba ny vihavavy - The woman is washing the clothes 3% [manasa] V [ni] [lamba] O [ny] [vihavavy] S [wash] V [the] [clothes] O [the] [woman] S Kanawa yano toto The man took the canoe [kanawa] O [yano] V [toto] S 0.9% [canoe] O [took] V [person] S Samũũy yi qa-wùh - People eat howler-monkeys [samũũy] O [yi] S [qa-wùh] V 0.1% [howler-monkey] O [people] S [eat] V Chomsky s theory does still have a few dissenters but it is overwhelmingly accepted by the majority of linguists and philosophers. Is Chomsky therefore an old-fashioned Rationalist who believes in innate ideas and knowledge? No. The reason is that Chomsky does not think we can articulate our software. You have a lot of clever stuff going on in your brain. If someone throws you a ball, you know how to calculate where it will end up and when and to move your hand to that point whilst shaping your fingers appropriately. Most people who can do this cannot explain how they compute the path of the ball. They just know. But it would be wrong to say that we all really do know the mathematics. And of those who could explain the mathematics, none of them actually do it consciously we simply can t do the maths that quickly. You can t bring to your conscious mind the mental program that does the work. By contrast, if someone asks you the times of the trains from Twickenham and you have memorised when they run you are bringing that information to mind. You can t bring to mind the grammatical rules you follow in constructing English sentences. If we could, there d be no need to study linguistics. They are too deeply embedded. For this reason, we do not speak of innate knowledge or innate ideas. But it does show that we are not quite so blank as Empiricist traditionally supposed Complex ideas Empiricists claim that all ideas are formed from experience. Hume issues those who oppose this view a challenge find me an idea that can t be explained as composed out of elements of experience! Kant will do just that, as we will see. But we can raise worries independently of him about what ideas can be explained, as we shall now see. Let s remind ourselves of the basic approach. We soak up colours, smells, and so on via experience and mix them into ideas of ever more complex things: apple, fruit, nature, reality. So long as we focus on things (shoes, badgers, trees) and their properties (red, heavy, wet), it looks easy enough. But we have lots of ideas that aren t so easy to explain in this way. Page 68/109

69 Chapter 10: Problems With Classical Empiricism - 2. Complex ideas Complex ideas Hume issues us a challenge: show me an idea that can t be explained as acquired on the basis of experience. We know that he dismisses God, necessity, self and substance. But what about philosophy, game, investment and democracy? It is not obvious what simple things we sensed on the basis of which we built these things. Of course, there may be some distance between the simple and the complex: Shapes + colours human body Shapes + colours + sounds distinctive behaviours Behaviours + body person. Feeling of resistance power. Power + person ruler. Reflection on my mind decision. Decision + ruler democracy. But who knows if this is right? It isn t enough for either side to say, Show me an idea that can / can t be treated this way! We need more proof than this. So, Hume and his opponent at best reach a stalemate here. Relational ideas It is crucial to remember that ideas, being composed of sensory elements, are a little like pictures or sounds or smells or combinations of them. Now consider the picture to the right. This is a picture of a rat on a cat. By ignoring or abstracting away from the rat and the cat we get the idea of on: one thing being on another. Don t we? No. The picture is also a picture of a cat under a rat. The picture represents both on and under. But you have two distinct concepts: on and under. A picture cannot represent the difference between them and cannot therefore be what we have to understand a word like on. The word on does not refer to a kind of thing and it does not express a property. It expresses a relation between two things. And relations can t be easily pictured. Consider another example: This is Socrates to the left of Plato. But it is also Plato to the right of Socrates. Left and right can t be pictured either. Negative ideas I can think that is a weasel. I can also think that is not a weasel. But how do I picture something negative? By putting a line through it? No. That is just a picture of a weasel with a line through it. And putting a cross or any other kind of mark on top will do no better. Shading the weasel in or erasing it will not do either. That is a picture of a white splodge. Or a weasel shadow. Or who knows what else? The point is quite simple. Pictures can only present what s there, not what is not. Logical ideas I can think the thought: Jim likes fish and chips and the thought John likes fish or chips. Simply putting the two together doesn t distinguish between the concepts and and or. Page 69/109

70 Chapter 10: Problems With Classical Empiricism - 2. Complex ideas You can t express or in a picture. It won t help to picture fish and then chips. That s no more clearly fish or chips than fish and chips. And and or are logical words. So too is if. And you can t picture if either. I can t picture the thought: if it rains, I ll stay in. A picture of rain and a picture of me at home could be the thought it is raining and Mat is at home. Or it could be Mat is watching the rain. Contrary to the saying, a picture isn t always worth a thousand words! Moral ideas Where do I get the ideas of good and bad from? An Empiricist has say that we experience lots of good and bad acts and spot what they have in common. But what is that? Good acts are ones everyone agrees are good. Good acts are ones that cause pleasure. Good acts are ones that feel as if they should be done. But you should be able to see that none of these work. An act can be good even if someone doesn t agree it is. (They can be wrong. Or mad.) A good act may cause pain to some. An act can feel as if it is something you should do such as drink because you are thirsty without being morally good. And what is to say that we get the same feeling with all acts of goodness or that we can t have that feeling in other circumstances? I might have a feeling of approval when I see someone give to charity but I might have that same feeling when the car salesman shows me the advantages of a new model. Hume was wrong to suppose there is always a distinct feeling. Theological ideas Empiricists say that we get our idea of God from experience. But how? God is an infinite being and we can t experience the infinite. We can experience the finite and magnify it. Having learned the small numbers 1, 2, 3 and so on, I can think of ever bigger numbers: , , and so on. But these are still finite and no amount of addition will get me to the infinite. Similarly, whilst I may experience one person being more powerful than another or more knowledgeable than another and whilst I may magnify these qualities, I will only ever get the ideas of very very (very )powerful and very very (very ) knowledgeable. I won t get infinitely powerful and knowledgeable: omnipotent and omniscient. Metaphysical Ideas Ideas like substance, self and necessity were real challenges for Locke. He thought there must be substance but admitted he could not say much about it. The same goes for the self: he was agnostic as to whether it was something immaterial (as Descartes said) or just the brain. He did not have a good explanation of where we get the idea of necessity from. Hume, as we have seen, takes the challenges on. In the next chapter, we ll see that Kant argues that experience cannot give us ideas of substance and cause and effect despite Hume s efforts. General ideas Locke said that a general idea is a general picture formed by abstracting from the details of particular examples. Berkeley said that there can be no such picture. A picture of a triangle is always a picture of a particular triangle. You can t picture all triangles at once. Berkeley and Hume accepted this. They had a different explanation. First, we begin with the fact that different triangles nevertheless resemble one another. Bernard is learning about the world. He sees a number of triangles and grasps that they resemble each other in a Page 70/109

71 Chapter 10: Problems With Classical Empiricism - 3. Simple Ideas certain way. He learns an ability to classify triangles on the basis of their similarity. He learns the word triangle as the word that is used to pick out things that resemble each other in this way. It is language that gives us the power to think in general terms. Now, when Bernard hears the word triangle, this brings to mind the idea of a particular triangle that stands for all triangles. Bernard knows that what is meant by triangle is all shapes that resemble this one. Everybody has their own idea of a triangle but we communicate successfully because we understand that by the word, we mean triangles in general. (*) There are problems with this strategy. One is that it doesn t explain anything. We want to know how Bernard can have the general idea of a triangle. We are effectively told that he (i) sees a triangle and (ii) learns that triangles are similar to it. But (ii) is what we want to know about. What has Bernard got in his head that enables him to do that? If all our thoughts are ideas, then all Bernard can have to help him are more pictures of triangles. But no matter how many pictures you have, you don t have the idea of a triangle in general as there are infinitely many triangles. 3. Simple Ideas What ideas are simple? I seem to see a banana. Is the shape a simple impression? I rotate it slightly is this a different shape? Or is it still a banana-shape? Is the colour a simple impression? As I look at it, I can see that there are many shades of yellow and spots of black. So, do I have one impression or many? And how do we distinguish one yellow from another? Do I have as many impressions (and then ideas) as there are shades of yellow? Problems arise here. For any shade of colour Y, you can find two other colours X and Z that are so similar that: You can t distinguish X from Y. You can t distinguish Y from Z. You can distinguish X from Z. If Y is indistinguishable from Z, then they are the same. There s just one impression here. But then everything else (in)distinguishable from Y should be (in)distinguishable from Z. But that s not true! X can be distinguished from Z but not Y. We are merely raising questions here but they are hard ones. It is not at all obvious how we are to determine what is truly basic. The Missing Shade of Blue Hume says that all ideas must come from impressions. But suppose we see a range of shades of blue with one missing. Surely we can mentally fill in the gap by extrapolation. If so, not all ideas require impressions. Hume actually raises this example himself and dismisses it without quite saying why. There is no universally-accepted explanation but the best explanation, I think, is that Hume is not committed to saying that to every simple idea there must be a simple impression but that families of ideas must be related to families of impressions. So, you could not have any colour ideas if you were blind, for example, and you could perhaps not form a taste of any meat if you d been vegetarian all your life. The Speckled Hen Suppose I look at a speckled hen, so speckly that I can t see how many speckles it has. It looks to have an indeterminate number of speckles. The Indirect Realist says that I have a speckled hen-shaped sensedatum. Now, this is like a picture. As such, it must show a determinate number of speckles. You can t Page 71/109

72 Chapter 10: Problems With Classical Empiricism - 3. Simple Ideas paint a picture of hen with a vague number of speckles. But if it has a determinate number of speckles, why does it not look that way? And why am I not aware of how many? The problem the objection highlights is that our perceptions of the world may be vague or indeterminate. Think of the haziness at the edge of your field of view or of the lack of clear definition to a busy scene (leaves rustling in the wind, a crowd, a speckled hen). Yet sense-data, as pictorial things, must be determinate. So, how do we explain why the world doesn t always look determinate and clear? Classifying simple ideas/impressions When I see a banana, I see something banana-shaped and yellow. But I can t simply have a bananashaped impression. To think of it that way presupposed I have the idea of a banana, which I can only get from seeing many bananas. Similarly, to see the colour as yellow, I must already have the idea of yellow. There is not one shade of yellow but many. The general moral is this. To classify, we must relate what we see to others of its kind. But this presupposes we already know the kind. In response, an Empiricist must say that we have a basic ability to identify some similarities. We are simply built that way. This is not the same as saying we have innate ideas, they will say. Misidentifying simple ideas/impressions I see a magenta patch or is it fuchsia? I taste ginger or is it galangal? I hear an oboe or is it a cor anglais? We can make mistakes about even our simplest sensations. So, we can hardly our impressions as the certain foundations of our knowledge. In response, the Empiricist might say that we can be confused about which idea/concept the impression falls under but we can t be wrong about the impression itself! There it is, slap bang in the middle of my sensory field! But even if this is true, it still means that we have no basis for knowledge. If I can t describe my experience in any way, I can t be said to know it in any way. All I can simply do is point dumbly at my experience and say there it is! If I know something, I must think about it in a particular way. If I know that that is ginger, then I think of the sensation under the concept ginger. Will it help to say that I don t know that my sensations are so-and-so but I know them by acquaintance. I know my red-sensation like I know Jim or Paris. but If I know Jim, then I must think of Jim a certain way. Perhaps I remember how he looks or what he is like. I don t simply know Jim by being put in front of him and seeing him! So, the price of saying that we are certain of our sensations as simply there is that we can t say anything about them. But then they are not the basis of anything. The Myth of the Given (*) The above problem of misidentifying our most basic experiences sensations or impressions is one that was pursued by the philosopher Sellars. All Empiricism begins with the idea that something is simply given. For example, it might be the sensation of a red disc. I need not think about what this is. That there is a red disc is simply given to me in my experience. So, there is no way I can be wrong about it and it can be a foundation for knowledge. Sellars attacked this view in various ways. First of all, Sellars points out that just because we are not consciously aware of anything other than this simple sensation in our experience, it does not mean that there has not been lots of unconscious processing to make it feel simple. For example, I might simply say that I see something banana-shaped but of course that I see it that way shows the influence of my concept of a banana. Similarly, faced with the two images below, I see them both as three dimensional but also as having sharp and smooth surfaces. Now, my ability to see three-dimensionally is not simple. I must learn to associate what I see Page 72/109

73 Chapter 10: Problems With Classical Empiricism - 3. Simple Ideas with what I feel. People who have been born blind or lost their sight early in life and had it restored in later life find it very difficult to see depth in the world properly. This sounds bizarre, but only because we are so used to seeing the world as naturally three-dimensional. In 1689, Locke famously posed the question to his friend Molyneux of whether a blind man whose sight was restored who could distinguish a sphere from a cube on the basis of touch could immediately tell which was a sphere and which was a cube if his sight was restored. Locke thought he could not, as did Berkeley. Modern research shows they were right. People whose sight has been restored need to learn the connections between how things look and feel. Second, Sellars pointed out that for me to classify anything is to bring it under a concept: to recognise it as an instance of a kind. I can t recognise a sensation as something before I have the concept. This suggests that the concepts must be there already: they must be innate. Sellars does not draw this conclusion. We clearly have a basic ability to respond to physical stimuli. Our brains must recognise stimuli and basic properties, such as the intensity and colour of a light, for example. To identify two colours as similar, though, is not yet to identify them as colours of a particular type. Nor should we think that we build up concepts one by one from particular experiences. It is rather that we learn whole groups of concepts gradually. We don t learn red on the basis of some experiences, then yellow on the basis of others. We are sensitive to coloured stimuli and we learn the colour concepts as a family that divide up the colour-space. Third, knowledge requires justification and justification is a matter of providing propositions not sensations. You ask me why I believe the shop is shut. I say: I saw the owner locking it. I provide you with a proposition that I say is true and it is its truth that matters: it is because it is true that it supports my claim (along with other propositions.) A sensation can t be true or false and can t justify anything. Fourth, to learn how to apply a concept is like learning how to apply a word. It not a simple process. In learning what red means I must have understood what my teachers were up to: that they were trying to teach me something. I must have understood that they were indicating the colour of the surfaces of things. I must have grasped conditions under which something is red (things are still red when it is too dark to see them redness is relative to normal conditions). I must understand that one makes classifications of colours in response to questions about them. You might say that Sellars is confusing learning how to use a word with a concept. Sellars would say that thinking and speaking are in this respect the same and learned together. There s no difference between me thinking a thought by myself and speaking it to others. If I am prepared to think it is raining, I would be prepared to say, it is raining. In sum, Sellars says that we are naïve if we think that, as mature thinkers, when we focus on a spot of red in our sensory field and identify as red with deep conviction, that we have come into contact with reality in as pure a way as possible. There are all manner of unconscious processes that get us there and all manner of background knowledge we must have acquired to get to that position. When we see the concert pianist play effortlessly, we would not assume that he has some simple and natural skill but that he has practised intensely. We must look at ourselves in the same way. Page 73/109

74 Chapter 10: Problems With Classical Empiricism - 4. Scepticism 4. Scepticism A sceptic is, originally, one who doubts. To be a sceptic in modern philosophical language is to be someone who doubts that knowledge is possible. We can believe but never know. The gap between appearance and reality naturally makes one sceptical. Can we really know that reality is as it seems? Despite their differences, Descartes and Locke agreed with the new science that distinguished between how the world is and how the world seems. Out there is a world of matter with primary qualities: shape, size and motion. The world out there can produce in me sensations of colours, tastes, and so on. This is the world I experience. But this raises an obvious difficulty. If all I know is my impressions of the world, how do I know that the world beyond is anything like them at all? Perhaps I could be massively wrong about how it is. It as is if we are trapped in a private cinema. On a screen, I see the world thanks to a camera outside: or so it seems. The camera is mobile so I can move it about to move through the world. But how can I tell the camera is telling me about the world out there? How can I tell that I am not being sent images of a false reality? Since I cannot get out, I cannot know. Locke claims without much argument that we can be certain enough. Hume goes further than Locke in his empiricism. He argues that we cannot be certain of anything beyond our own perceptions. I can be sure that I am visually experiencing a yellow disc but I cannot be sure that it is caused by and represents the sun in the sky. I cannot get beyond my experiences to see how they are caused. I am trapped in my world of experience. Observe that the scepticism runs very deep. It is not just that I cannot know about the world out there. I cannot know about the past both out there and in here. In order to know the past, I would need to be able to trust my memory. But there is no logical link between my recalling something and it having happened: it could be an illusion. We would have establish that memory is reliable by induction. But, as Hume shows, we can t rely on induction. And induction is our basis for knowing the laws on which we predict the future, so we can t know the future either. We can only know the present. 2 Solipsism An extreme form of scepticism is solipsism. This is the view that my mind or, in your case, your mind is all that exists. Everything that you seem to sense is a fabrication of your mind. Locke and Hume can t resist the possibility that solipsism is true. Yet surely we want philosophers to prove that we are not alone! Hume has argued that we can t be certain of anything beyond our experiences, that the world that appears to be structured around causal relations is merely a world of regular appearances and that a very natural way of learning and indeed doing science has no rational basis. Hume argued that our minds are built in such a way to make it irresistible that we exist in a world of objects and other people, that things stand in causal relations and that induction makes sense. We are naturally inclined to believe in all of these things. Other philosophers hoped to show that the reason we are naturally inclined is because this is how reality really is. Hume stands in the history of philosophy as the Great Sceptic who argued that philosophy has no power to prove such things. But just because we are naturally inclined to believe in the external world, philosophy will never drive us to despair or insanity: [S]ince reason is incapable of dispelling these clouds, nature herself suffices to that purpose, and cures me of this philosophical melancholy and delirium...i dine, I play a game of back-gammon, I converse and I am merry with my friends; and when after three or four hours' amusement, I would return to these speculations, they appear so cold and strain'd, and ridiculous, that I cannot find in my heart to enter into them any further. (Treatise, Book I, Part IV, Section VII, p. 269) Page 74/109

75 Chapter 10: Problems With Classical Empiricism - Summary At the very least, a philosophy that leads us me! to the conclusion that only my mind exists is one we might think has taken a wrong turn. It should force us to look elsewhere. This was Kant s view, as we shall see in the next section. Summary The view that all ideas come from basic impression or sense-data which are known with certainty has come under repeated attack. o We can be uncertain what we are experiencing. o It is unclear what sensations are basic. o Even the most basic sensation is shaped by our experience of the world. Complex ideas are not always easy to analyse into simple ones. This suggests some ideas might be innate. Finally, empiricism seems to cut us off from reality. 1 Finally, let us note something a little different but no less impressive. You have to learn the meanings of all of those words. Recent estimates suggest the average 18 year-old knows about 60,000 words. That works out at over 3000 a year, nearly 300 a month and about 9 a day. Since you are not learning words from the very first second of birth and the pace slows down when you are a teenager you re tending to learn relatively rare and complex words now, this means you re learning over 20 words a day in the vocabulary spurt period between about three and eight years old. 2 In the 19 th and 20 th century Empiricists responded to this problem by analysing the external world in terms of sensations. They were called phenomenalists. They were a bit like Berkeley the idealist. The apple on my desk is really a collection of sensations. More precisely: all that can be said or known concerning the apple on the table is that, in certain circumstances, I will experience certain patterns of sensations. They did not claim that there are ideas out there existing in the mind of God. They were more cautious. They simply said, in a Humean way, that we are not really committed to believing a world of things beyond our senses that are puzzling and unknowable. All our talk of things can be in principle translated into talk of appearances. We simply don t bother because it is too complicated. Page 75/109

76 Chapter 11: Kant and Kantianism - Introduction Chapter 11: Kant and Kantianism Introduction Kant looked at his philosophical predecessors and divided them into Rationalists and Empiricists. The Empiricists were right to say that all knowledge of reality comes from experience. There are no innate ideas of it. They were wrong to think that our minds are blank slates, though. Our minds needs ways of organising the raw data of experience for us to have our coherent, structured experience of the world. Our minds have a priori concepts that perform that role. This makes Kant sound like a Rationalist as a priori concepts are not learned and so innate. Kant argued that the Rationalists were wrong too, though. We don t have any ideas of a reality beyond the senses. All our ideas do is organise our experiences. The only reality we can know is the reality the senses present us. Hume said that the mind spreads itself onto the world. We think we cause lead to effect out there when in fact it is merely our minds making us think that way. We see one thing then another enough times and we start to take the one as a sign of the other. Kant s view is similar. Our mind that shapes the world. But it is shaped by concepts we do not learn. Kant thought that Hume s view of the mind was too simple. Hume said that ideas simply occur in our minds and that we have very limited powers to combine and associate ideas with one another. Kant said that such a mind would not be powerful enough to give us the organised experiences we know we have. There must be more to it than that. Hume divided knowledge claims into two categories: relations of ideas and matters of fact. Kant relabels these the analytic and the synthetic. The analytic are mere truths of definition and knowable a priori.. The synthetic are substantial facts and knowable a posteriori. Kant said we need a third category: the synthetic a priori. A synthetic a priori truth is a truth known by reason alone but not a trivial truth of definition. It is a truth about the structure of reality. But the structure of reality is imposed by the mind on the world. So, it is also a truth about the structure of the mind. By doing philosophy, we work out how the mind shapes the world. By doing science, we work out what that structured world is really like. Philosophy does not reach beyond the world of the senses but reaches into it to uncover its hidden structure. Kant took as his challenge the question How are synthetic a priori propositions possible? In this chapter, we ll consider Kant s arguments for his view and his category of the synthetic a priori. Kant s Revolution: The Rationalists Kant started his philosophical life as a rationalist but famously said that Hume shook him out of his comfortable rationalist assumptions. The problem with Rationalism was that it went too far in the other direction by ignoring experience. Rationalists essentially think that reason can leap over the world of experience and get straight to reality directly. But Kant argued that we cannot do such a thing the only world we can know is the one we experience. Kant argued that when we let pure reason loose, we get tied up in knots. We find ourselves able to prove that p is true and then also that the opposite is true! When such conflicts arise, the traditional response from each side was: let s find better arguments to defeat the opposition! Kant s radical suggestion is: give up! You are pushing reason beyond its limits. Reason can only work within the limits of experience. Here is an example of the kind of contradiction or antinomy we can develop. (Don t worry too much about the details as you won t be asked to reproduce it! The key point is simply that pure reason cannot tell us about what reality is like.) On the one hand, you can argue that the time must be infinite that the universe is infinitely old. On the other you can argue that time must be finite that the universe must have had a beginning: Page 76/109

77 Chapter 11: Kant and Kantianism - Kant s Revolution: The Empiricists Jim: Of course time is infinitely old! Consider your beginning. What does it mean to begin? It means: there was a time when you didn t exist and then a time from which you do exist. So, if time came into existence, then there was an empty time before it existed. But empty time is just time. So, the very idea of time beginning is nonsense. Bob: Of course time is finitely old. Suppose otherwise. Then as of this moment now, infinitely many moments have already passed. But that makes no sense. Think of moments as grains of sand. To a pile of sand you can add more and more grains of sand but you ll never get infinitely many. You just get a bigger finite number. Of course, we say that you can go on adding grains forever- ad infinitum. And that s true. But all that means is: nothing stops you from keeping on adding. It does not mean that there could be a completed pile of infinitely many grains of sand! In the same way, it s just nonsense to suggest a complete period of infinitely many moments has passed. Pure reason can lead us astray. We need to apply our powers of reason to the world we experience. Reason and experience must work together. Kant s Revolution: The Empiricists Empiricists are right to say that all knowledge of what exists in reality is a posteriori but wrong to think that experience can generate all our concepts unaided. Our experience is simply too structured for an essentially blank mind to have built it all up by merely storing up ideas and combining them in the way Locke and Hume supposed. We have certain a priori materials that organise the raw data of experience. We shall examine Kant s attack on Empiricism in more detail shortly. Kant said that both Rationalists and Empiricists shared the assumption that our minds are wholly receptive to reality. Reality is "out there", already built in a certain way, and it is up to the philosopherscientist to discover what it is like, be it through reason or experience. Kant said that this assumption had to go. He promised a revolution in philosophy like that which Copernicus wrought in astronomy. Our minds are active in shaping experience. The world we can know about is as it is because our minds make it appear that way. It is the mind that shapes the world, not the world that shapes the mind. This was Kant s revolution. Scheme and Content Here is a well-known analogy to get the feel of what Kant is on about. Imagine that all your life you have been wearing a special set of tinted lenses implanted in your eyes. You have not realised this up to now. The tints in the glasses are responsible for the colours you experience. Up to now, you thought, naively if understandably, that you saw the world as it really was. No. The way you see the world is a combination of the real nature of the world plus the lens that filter it and make it appear a certain way. Now imagine these lenses in the mind. They filter experience and make the world appear one in which there is a three-dimensional space, in which there are objects and in which there is causality. (Kant calls these filters categories and concepts the distinction doesn t matter for us.) So, the world is as it is for us because our minds make it so. We are making a crucial distinction between scheme and content. The senses feed us raw data. Our mind imposes a scheme. This is a framework of concepts. The scheme organises the raw data. The result is (conceptualised) content: our organised experience of the world and thoughts about it. So, it is because I have a certain scheme that my experience is of a three-dimensional world of objects existing in time and which enter into causal relations. It is because my experience is thus structured that I Page 77/109

78 Chapter 11: Kant and Kantianism - Phenomenal and Noumenal am able to form concepts such as cup and desk via experience and think structured, conceptual thoughts such as there is a cup of coffee on my desk. Should we try to take our mental glasses off? We can't, says Kant. Experience structured, coherent experience is only possible with glasses in place. You need something to structure the raw data of experience that enters your eyes, ears, skin, and so on. The world does not imprint its structure upon us. We cannot simply passively "pick up" on the structure in the way that the Empiricists and Rationalists supposed. We are therefore not tabulae rasae. If we were, we simply could not get started. For if the world doesn t tell us how it is structured, we have no reason to process or interpret the data one way or another. Even if we did hit upon a way of making sense of it, it would be a miracle if we all hit upon the same way. And yet we do. That we fundamentally see the world the same way is a precondition of our communicating and interacting in it together. Phenomenal and Noumenal The world that we can be aware of Kant calls the phenomenal world. It is this world that empirical truths are about. It is this world that science investigates. It is the world that we experience through our minds making it appear a certain way. The world as it simply is, that lies beyond experience, that we mistakenly think we could see if only we could take off our glasses is the noumenal world. We cannot know anything about it. We can know it exists and is responsible for the phenomenal world, in conjunction of course with our structuring minds, but that is it. It is very important to understand that Kant did not think the phenomenal world is Hume s inner world of sensation. He was at pains to stress that it is the real world. Kant denied that there is an unbridgeable gap between experience and reality. There is an unbridgeable gap between the world-as-experienced and the world-as-it-is. This is a subtle but vital distinction. Empiricism leaves us with an image of the mind as representing reality via distinct ideas of it. It is as if our access to reality is via inner photographs of it. 1 Crucially, a photograph is a distinct thing from what it is a photograph of. One can exist without the other. Hence, one can wonder if there is indeed anything out there that the photographs are supposed to be copies of. By contrast, Kant wants to say that (in effect) that we simply see reality but in so doing we make it our own. Our visual sensations are simply the way that our eyes tell us about reality. Do they come between us and the world? Yes and no. In order for the world to get into my mind, it has to be represented some way or other. But this doesn t entail that the representations are things that leave us cut off from reality. Consider the glasses analogy again. My eyesight is not perfect. I wear glasses. Thanks to them, I experience a focused world. Now, the world I see now is not some kind of second world magically created by my glasses. It is, simply, the world focused. Now, whether we wear glasses or not, we all have natural lenses in our eyes. They focus the world for us; without them, we would be aware of fuzzy coloured patches of light and dark. But we don t think that these lenses create something new; they make experience of reality possible. Going still further in, we need lenses in our mind concepts to make the same thing happen. Here is another way of making the point. To talk to about reality I must use a language. I can tell you that there is a badger in the garden using just those worlds; equally, I could say Il y a un blaireau dans le jardin. Jest borsuk w ogrodzie. Meles est in horto. Page 78/109

79 Chapter 11: Kant and Kantianism - The Analytic and the Synthetic Now, do the words get between me and you and reality. Yes and no. Yes: they are a middle layer. But no: they don t cut me off from reality; they make talking about reality possible. A final way to think about Kant s idea is this. Suppose science reveals something new about the basic particles of the universe, such as electrons: they aren t basic. We know that they have an inside but we also know that we shall be unable ever to peer inside. We humans simply cannot create the technology to open them up. We know that what is inside makes these particles behave as they do. Reality is essentially what it is because of the hidden natures of these particles. Yet our knowledge of reality can only go so deep. We see the surfaces of things, not their innards. Yet it is still reality we are seeing. In the same way, thanks to our senses and our minds, we see something like the surfaces of things, not what lies behind. But there is just one reality, ultimately; there are simply two levels of knowledge we can have it: ours and God s. The Analytic and the Synthetic We have met the a priori/a posteriori distinction and the necessary/contingent distinction. We now need to meet the analytic/synthetic distinction. In fact, we ve met it already. It is Hume s difference between relations of ideas(=analytic) and matters of fact (=synthetic). Here are some examples of the two: Analytic A bachelor is an unmarried man A square has four sides All fish can swim Synthetic Jim is a bachelor My garden is square. My cat eats fish. Intuitively, the distinction is this: Analytic: if a proposition is analytic, it is true (false) just in virtue of the ideas in it or the meanings of the words. Synthetic: if a proposition is synthetic, it is true (false) because of how the world is. So, a square has four sides is true because the idea of a square just is the idea of a certain four-sided shape. It is true by definition we might say. Whether my garden is square is true or not clearly depends on how the world is. Kant said that in an analytic proposition, one idea or concept was contained in another one. In the case of a square has four sides, we can distinguish two concepts: the subject concept: square the predicate concept: four-sided The words subject and predicate come from grammar. The subject is what the sentence is about and the predicate is what is said about it. In simple English sentences of the form a is F (Jim is happy, Paris is a large city in Europe, etc.), a is the subject and is F is the predicate. So, Kant said that in an analytic proposition, the predicate concept is contained in the subject concept. Think of a concept as like a little dictionary entry. Then in the entry for square you will find four-sided. Similarly, in the entry for bachelor you will find unmarried and man. Because the predicate merely unpacks what is in the subject, analytic propositions tell us something trivial. We don t learn anything new by hearing that a square has four sides we knew that all along! By contrast, if you learn that my garden is square, you do learn something new. For in the subject-concept my garden, you will not find square. My garden is not by definition square it just happens to be that way. So, in a synthetic proposition, the predicate concept is not contained in the subject concept and so we get new knowledge out of it. Page 79/109

80 Chapter 11: Kant and Kantianism - The Analytic and the Synthetic Because an analytic proposition merely unpacks a definition, it states something necessarily true. Kant said that analytic truth cannot be denied without contradiction. This is easy to see. A square does not have four sides is contradictory. Unpack square and you get four-sided figure whose sides are of equal length. So, we are saying A four-sided figure whose sides are of equal length does not have four sides. That s a plain contradiction. And so, a synthetic statement expresses a contingent truth. Finally, analytic truths can be known a priori: you are merely examining ideas in your mind. Synthetic truths can only be known a posteriori: you need to see if the world is that way. So, we get a nice line up: Analytic necessary a priori Synthetic contingent a posteriori All of this is just as Hume saw it. We have merely done what Kant did: put it all in his own words. Hume, remember, was happy to say we could have a priori knowledge of necessary truth because they were merely analytic truths. They simply tells us about ideas, not about the reality beyond. Analytic and Tautologous Kant defined an analytic proposition as: one where the predicate concept is contained in the subject concept one that cannot be denied without contradiction. Many have thought Kant s first claim is too narrow. Consider the following claims: 2 = 2 If Jim is taller than Jane then Jane is shorter than Jim. These are like a bachelor is an unmarried man in the sense that you know they are true just by grasping the concepts involved: 2=2: my grasp of equals means I know that x = y is true if the same thing is on either side. If Jim is taller than Jane then Jane is shorter than Jim: my grasp of taller and shorter allows me to know this for any two people it s irrelevant who Jim and Jane are (or even if they exist.) These claims are often called tautologies. A tautology is informally defined as a kind of repetitive truth : one where you needlessly repeat information. We know everything is identical to itself, so it doesn t tell me anything to say 2=2. We know that if Jim is taller than Jane, this means Jane is shorter than Jim there s no point in adding it! A better definition is that a tautology is a truth true by definition. So, some say that Kant should have broadened his notion of analytic to cover all sorts of truth where the necessary connections between the ideas or concepts alone make it true. Tautology and Logical Form (*) more formal definition is that a tautology is the following: a tautology is a truth true in virtue of its logical form. This idea is best explained by example. Consider the sentence: London is London. The form of this sentence is: Page 80/109

81 Chapter 11: Kant and Kantianism - What Experience Cannot Do: Structure and the Synthetic A Priori X = X. We have merely replaced the X with London. Now, = is a logical concept. We know that X = X is true for any X. That simply comes from understanding the concept. So, we know that London = London is true because of the form. The fact that it mentions London is irrelevant. In the same way, consider: If Jim likes cheese and Jim likes coffee, then Jim likes cheese. The form here is: If P AND Q THEN P. No matter what we put for P and Q, we get truths: this is just what IF and THEN mean. The philosopher Frege argued for the idea that analytic truths are tautological in this sense. Faced with a sentence we need to ask if we can reduce to a truth true in virtue of its logical form replacing terms where necessary by synonyms. So: A square is a four-sided figure. o Synonyms: square, four-sided figure. o Replacement: A four-sided figure is a four-sided figure o Instance of logical truth: X = X. What Experience Cannot Do: Structure and the Synthetic A Priori Having distinguished the analytic and the synthetic like Hume, Kant exposed the problem he saw with Empiricism that we mentioned above. A blank mind that simply lets experience flood in and can merely store and add ideas in the way the Empiricists supposed could not give us the structured experiences we know we have. There must be in-built structures ready to organise or mould the raw data of experience. We have a priori intuitions of space and time. We don t learn what they are from experience. When the raw data of experience floods in, our minds arrange it so that the world appears as a world of three-dimensional objects that exist over time. We have a priori concepts of cause and effect and substance (amongst others). Again, these are like lenses that structure raw perceptions in certain ways. I don t simply see the match strike and the flame light: I see the strike cause the light. I don t merely see a green disc and smell an appley smell. I see a thing that smells and looks a certain way. Truths about these concepts, such as every event has a cause, are synthetic a priori truths. They are not learned from experience. They are not trivial. They are truths about how the mind structures reality. The same goes for mathematical and geometrical truths. Maths and geometry are not trivial but substantial areas of knowledge. They are not analytic truths. But they are necessary truths, so can t be learned from experience (remember Leibniz). Their truths are synthetic a priori. Kant thought that his discovery of the synthetic a priori was hugely important. We shall consider two examples of such truths that bring out his concerns with Empiricism. Cause and Effect: The House And The Boat (*) Kant was particularly annoyed by Hume s theory of cause and effect. The claim at issue here is: Every event has a cause. Page 81/109

82 Chapter 11: Kant and Kantianism - What Experience Cannot Do: Structure and the Synthetic A Priori Rationalists would claim we can know this a priori perhaps because we have innate ideas of God s laws of nature. Hume said that this is merely something we come to believe a posteriori on the basis of experience but cannot be shown to be certain. All we mean when we say that every event has a cause is that, so far, that s how it has seemed. And all that we mean by cause and effect is that we expect one thing to follow another. We don t see cause and effect in reality. Our minds merely interpret things that way. Kant argues that this is an example of a synthetic a priori truth. It is not analytically true. This would mean that every event has a cause is like every bachelor is unmarried: something we can see is true simply because one concept is contained in the other. It is not knowable a posteriori. The concepts are presupposed by experience, not learned from it. What s the proof? It is not analytically true. If something is analytically true, it is necessarily true. If it is necessarily true, denying it is contradictory. But it is not a contradiction to say not every event has a cause. Some people, after all, think there can be uncaused events. It is not knowable a posteriori. The ideas don t come from experience. Here s why: Kant asks us to consider having three perceptions of a boat on a river. I experience this as three perceptions in time: one, then another, then the third. Exactly the same is true when I have three perceptions of the different parts of a house: But even though it takes time me to view the different parts of the house, I think that I am seeing the house at one moment. I don t think the house is changing. There is merely a subjective difference in time. By contrast, when I have the three perceptions of the boat, I do think that I am seeing the boat at three different times. I think that there is an objective difference in time. I think that there is cause and effect: the earlier position of the boat causes the later position. There is change in the world. But I don t think that there s any cause and effect with the house. The roof doesn t cause the window! There is no change in the house. There is only in a change in me what part of the house I see. So what? Well, in order to be aware of cause and effect, there s clearly more going on that simply having a sequence of perceptions. Kant says I must think of the sequence as necessary and irreversible. I looked at the roof, then the window then the door but I could have looked at the door, then the window, then Page 82/109

83 Chapter 11: Kant and Kantianism - The Importance of the Synthetic A Priori the roof. I would still have thought I am looking at a house that isn t changing. The order is not necessary and is reversible. But if I am to think of the boat s position as changing, then I must think that those positions must have occurred in that order. If my perceptions of the boat were in reverse order, I would have to think that the boat was moving upstream rather than down stream. Kant s point is then that what makes me think of some perceptions as having to be in that order cannot be something I get from the perceptions themselves. My perceptions simply happen, one after another. Something must already be present in my mind that infuses or structures some sequences of perceptions such that I think: had these perceptions been in a different order, the world would have been different. When that happens, I am seeing change in the world or cause and effect. When I don t think that about my perceptions, I simply think that I am taking time to see something unchanging in the world beyond. If I were a really simple creature, I would have a mind in which perceptions simply happened. I would not know any difference between changes in me and changes in the world. I might guess at which sequences represent real change. But I could get it wrong. This is what a Humean creature would be like. But we re better. We don t get it wrong. We all agree on when there is real change. We all have minds built to structure experience in the right kind of way. So, every event has a cause is a synthetic a priori truth. Maths: 7+5=12 As we know, this is a necessary a priori truth. Hume argued it was a relation of ideas or analytic truth. But it is not. The concept of a bachelor is the concept of an unmarried man. We can decompose it into these parts. So, man is part of the concept bachelor. You can t understand the concept of bachelor without understanding the concept man. It is contradictory to deny that a bachelor is an unmarried man. It is thus clearly an analytic truth that a bachelor is a man. But I can't "decompose" 12 into 7 and 5. They are not its constituents. 12 can be mathematically decomposed into 7 and 5, of course. But it can be mathematically decomposed into infinitely many sums: 6+6, , , and so on. They can't all be "in" 12. Otherwise, I'd (a) grasp an infinite mount of information when I grasp 12 and (b), I could "see" instantly whether any pair of numbers added to 12 (or, indeed, subtracted to 12, multiplied to 12, and so on.) And there s no contradiction in denying that 7+5=12. Someone learning maths may genuinely be uncertain whether it is or not and mistakenly but coherently deny that it is. So, it must be a synthetic a priori truth. The Importance of the Synthetic A Priori Kant saw his discovery of the synthetic a priori as an extremely important one. It is just these sorts of truths that philosophy must interest itself in. The Rationalist wanted us to be able to have knowledge of reality by pure reason. They wanted to do this by reflecting on concepts such as GOD, SPACE, TIME and so on. Kant argues that when our minds are allowed to wander in the gardens of pure speculation, they get lost and confused. We cannot leave the sensible world behind and hope to transcend it, as they dreamed of. There are necessary analytic truths we can know a priori: a bachelor is unmarried, for example. But there are no substantial necessary analytic truths we can know: ones that capture how reality must be. The Empiricist wanted us to have knowledge of reality by experience. Reason is there merely to reflect on our experiences to form more abstract concepts. But experiences don t come pre-organised. Experiences are raw data. Minds are needed to structure the data to make knowledge possible. Once done, there is a posteriori knowledge to be had. It is the stuff scientists should be looking for. But it presupposes a framework. Page 83/109

84 Chapter 11: Kant and Kantianism - Summary So, the job of the philosopher is to examine this framework. In so doing, the philosopher will be uncovering the principles that explain our experience of the world. So, the philosopher will find (claims Kant) that every event has a cause. For he shall find that this must be true for our experience to be possible at all. We cannot go into the details, but Kant essentially claims that if we didn t have minds that thought in terms of cause and effect, we wouldn t have minds at all. For a mind cannot function in chaos and chaos is avoided only by events occurring in a structured way. To fall into patterns of cause and effect is to be structured. So, it has to be true it is necessarily true that every event has a cause. But it is not a truth we discover about reality in a Rationalist way by ignoring experience and jumping over it to look at reality. It is a truth we discover by reflecting on our experience of the world. Kant does not think that our mental glasses or software are optional. He says that experience must be organised the way it is to be possible at all. Any creature capable of experience will need to share the same mind-design. For example, every creature must experience things in space and time. We cannot conceive of genuine experience of a timeless and spaceless world. There would be no way of distinguishing sensations and hence no thought about them and hence about anything would be possible. Every creature must likewise experience a world full of substances and observe causes and effects. If we simply experienced a varying mosaic of sensations, we d have no way of distinguishing between sensations from out there and sensations from inside what is imagined or dreamed. But if there is no such distinction between inner and outer, then we could not think of ourselves as distinct from the outside world. If we can t do that, we dissolve or disappear: there is no longer a subject of experience for whom there is a world. So, when Kant says that we are not to ask questions about noumenal world, it is not because he thinks we re simply not in a good position to know what it is like (as Hume might have concluded). We are necessarily debarred from getting any closer to it than we already are. But, at the same time, we are as close to it as can be far closer than Hume could have because a world is only knowable through experience (a rock doesn t experience and hence know anything) and experience presents it in the only way possible. Kant s program is therefore as follows. The scientists are given their now-traditional job of examining reality (phenomenal reality) via sets of experiences observations of experiments to come up with laws and explanations. The philosophers are to take a step back and examine not this or that set of experiences but experience in general. Given that we have experiences, what can we deduce about the organisation of the mind? The fruit will be necessary truths about how the mind must be in order for experience to be possible. But they are synthetic a priori truths because they are made true ultimately by experience, not concepts alone. In conclusion, therefore, Kant thought he had rescued philosophy from Hume s destructive program. Philosophers aren t psychologists or scientists who gather more and more a posteriori knowledge. They do gain substantial a priori knowledge of necessary truths. But they do not do this by ignoring experience and reflecting on concepts. They do it by reflecting on experience to determine what the concepts are like that must structure it. They can then present their discoveries in form of necessary truths about the concepts we must use. Summary Our question is: How do we know what we know? How do we gain certainty? Kant says: We have analytic a priori knowledge of such things as all triangles have three sides. The concepts are connected and reason shows this to be true. We get these concepts from experience, though the Empiricists were right about that. Page 84/109

85 Chapter 11: Kant and Kantianism - Questions We have synthetic a priori knowledge of such things as every event has a cause and 7+5=12. These are not true by definition. They are true in virtue of the scheme our minds have to structure experience. Perhaps we have a posteriori knowledge in science. It depends on whether science can establish things with certainty. We cannot know the noumenal world but that does not mean we are cut off from reality: our minds make reality available to us in the only way possible. Questions 1. Space is infinite! says Jim. How could you prove this? 2. Space isn t infinite says Bob. Infinity doesn t make sense! Suppose I am to run a 100 metre race. I run 50 metres. I am have run half-way. 50 metres remain. I run 25 metres. I have run half the remaining distance and 25 metres remain. I run 12.5, this being half the remaining distance. And so on What conclusion will Bob draw about his ability to cross the finish line? What does this show about the idea that we can divide space ad infinitum? 3. Kant says we see a three-dimensional spatial world and this must be so. Can you imagine living in a 2D world? A 4D world? 1 (*) If we re being careful here, a better image would be this: it is as if our knowledge of reality comes from reading letters about it. For Empiricists did not think that their ideas were simple copies of things in reality. Reality doesn t contain anything really red but rather structures disposed to induce red sensations in us under the right sort of conditions. Our ideas represent but do not resemble reality, as we previously put it. Yet photographs do resemble. Letters represent without resembling, hence their greater appropriateness. The crucial point remains: that the letter is a distinct type of mental item whose existence is not logically dependent on anything in reality. Page 85/109

86 Chapter 12: Problems With Kant and Kantianism - Introduction Chapter 12: Problems With Kant and Kantianism Introduction Kant seems to promise the best of both worlds. Our knowledge of reality doesn t outrun sensory experience. At the same time, we don t have to rely on experience alone as the source of all our concepts, which is good as it was struggling to account for them. But Kantianism has its problems too. Kant s philosophy is complex, so we ll not go too deeply into the problems. We shall mention two: Does the mind create the world? Kant s analysis of maths and geometry won t work. Realism and Idealism Hume said that we could not advance beyond our ideas to their causes. Kant thought that this was unacceptable. It meant that we had to accept one of two unpalatable theses. Scepticism about the external world: that we have no knowledge of it. This means we can t do science. This is not good. (Hume s view.) Idealism: that the world is nothing more than ideas in my mind or God s. There is no reality beyond my ideas. This is just mad. (Berkeley s view.) Kant argued that we can know that there s a world out there we re part of. He was a realist. He admitted that by reality, he meant phenomenal reality, or reality-as-it-appears. We know that there is more to the world than how it appears but that s all we know about the noumenal world. We cannot know that it exists but not what it is like. So Kant seems to cut us off from reality. What we know is what our mind lets us see. But then we re back to Hume or Berkeley. Kant was indeed accused of being an idealist and went to great pains to say that he was not. The mind doesn t generate the world but shape what is out there about which we can say absolutely nothing other than that it is out there. Kant tried to prove this in a rather complicated way. Very roughly, Kant observed that we can and do distinguish between sensations that are illusory (like dreams and illusions) and sensations that are real (of the real world). This distinction would be impossible if the mind was the source of all our ideas. In order for us to distinguish appearance from reality, there must be a reality we are part of and aware of. It is fair to say that most philosophers don t think Kant s proof worked. As a consequence, the reality we know is merely appearances. This isn t what we re after. We don t have knowledge of reality after all. Science and Experience Kant also argued that Hume was wrong to say that we can t know whether the sun will rise tomorrow. I really do see one thing cause another. My mind shapes the world so that sometimes, when I see A then B, I know that there is a necessary and irreversible connection between them. Where there is cause and effect, there are laws of nature. The reason I see the releasing of a ball (cause) lead to the falling of the ball (effect) is because there s a law of nature at work here to do with gravitational forces. My mind has to make my experiences structured or experience structured, coherent experience would be impossible. I would be witness to simply a chaos of sensations. So, I can know that the laws of nature will hold Page 86/109

87 Chapter 12: Problems With Kant and Kantianism - Science and Metaphysics tomorrow because my mind will continue to shape the world that way, and that because my mind has to shape the world to make experience possible. In reply, one can accuse Kant of confusing psychology with philosophy. It may be true that to be the sort of being I am, I need a kind of mind that I have, just as I need the kind of heart and liver that I have. I may not be able to know chaos. But all that means is that my mind will make reality appear organised so long as it can. There s nothing to stop reality changing so radically tomorrow that my mind is overwhelmed and I can no longer think rationally or coherently. Science and Metaphysics Kant argued that we see space and time the way we do because our minds make us see them that way. We see substances and causes and effects for the same reason. This means that we can t see the world any other way. But why believe this? As it turns out, advances in geometry and science in the 19 th and 20 th have challenged our views. Let us begin with geometry. Our intuitive picture of space is as a three-dimensional void, infinite in all directions, as below. When you do geometry in school, you study two-dimensional space which is likewise infinite in all directions. You represent it with an x- axis and a y-axis. Let us do so and draw a triangle: Now, that s just how space has to be right? No. Space can be curved. Imagine the surface of a beach ball and draw a triangle on it. The triangle is fatter or bowed and the angles add up to more than 180 C. You can also have spaces in which the angles add up to less than 180 C. The shape here is a saddle rather than a beach ball. Now, our space is three-dimensional but the same possibilities are open. Astrophysicists are investigating whether our universe has a flat, open or closed space. Kant also said that time and substance were a priori matters. We know, for example, that time ticks away at the same rate for everyone and that nothing can be in two places at once. Yet science has overturned these ideas too. Einstein discovered that time doesn t tick at the same rate for everyone. Time and space are intertwined. Whose watch shows the same time as yours depends on how fast you are moving! Particles like electrons can behave in ways that make them seem as if they are in more than one place at once. The details are unimportant. What is important is that we should not presume reality to have one kind of space rather than another. We need to investigate the matter scientifically. Kant, however, had said that space was a topic for metaphysics. The shape of space is knowable a priori because it is a feature of our minds. Kant, it seems, was wrong. Page 87/109

88 Chapter 12: Problems With Kant and Kantianism - Mathematics and Psychologism Mathematics and Psychologism The accusation of confusing psychology with philosophy was also levelled at Kant s account of mathematics. Kant, remember, said that 7+5=12 is a synthetic a priori truth because it is not a trivial truth of definition. So how do we get to know mathematical truths? Very roughly, Kant said that we get our mathematical ideas from pure intuition of the passing of time. Time, remember, is an a priori intuition for Kant or something in-built. We are aware of time passing in moments, as we become aware of one thought or sensation succeeding another. We then have the idea of a sequence of moments. Once you have the idea of a moment and a sequence, you have the materials you need. Imagine a moment as an notch I that you could carve in a stone. You can add another: II. And another: III. And so on. You have 1, 2, 3 and 4. You realise that you can keep adding notches in a specific order without end. You have the natural number sequence: 1, 2, 3, Indeed, this method of counting by notches or tallying is the oldest system we have. The Ishango Bone below, dating from c. 20,000 B.C. is one of earliest bits of evidence for humans counting. (Quite what they were counting is disputed.) So, I get my ideas of numbers from my awareness of time passing. My ideas have certain necessary connections between them, which is I why grasp that 7+5 must be equal to 12. The problem with this is that it confuses a psychological story about where my ideas come from with a mathematical story about what my ideas are about. According to Kant, it is the structure of my mind that makes 7+5=12 true. But that can t be correct! You and I have different minds but we both believe that that is true. But that we both believe that 7+5=12 is not like us both believing that Marmite is tasty. You and I could legitimately have different beliefs about Marmite because we have different minds or tastebuds. But if you don t believe that 7+5=12, then you re simply wrong. Another way of seeing the point is this. Suppose, for comparison, I form the ideas of certain beings in a certain world doing certain things. I have an idea of a man called Jim who lives in a place called Norut, who works as a unicorn-trainer. All my ideas and beliefs may hang together in a coherent way but that doesn t prevent them from being a coherent fiction. In the same way, if my mathematical beliefs are true, then they must be made true by something other than my mind. 1 The view that numbers are just subjective ideas is known as psychologistic theory of mathematics. Such views are unpopular because they can t explain the objectivity of mathematical truth. It is easy to be drawn to such a view because the obvious alternative is that mathematics is about something outside of minds. But numbers are not like cats: they are not things we sense. Plato said that we all have ideas of a mathematical reality beyond us. But that is also mysterious. In Kant s favour, we can say that a widelyaccepted theory of what makes mathematical statements true let alone necessarily true! has not yet been developed. 1 A different way of looking at Kant is as giving us an explanation of where our mathematical ideas come from, not what they re about. My mind is built a certain way, thanks to which I can think about numbers. My cat lacks such a mind. My ability to think about numbers may have come from an ability to think about time. It might be that each of us goes through a stage in which we move from a sense of time to a sense of number or it might be that our ancestors did so over time and that our brains have subsequently evolved. But even if this is true, it is just an Page 88/109

89 Chapter 12: Problems With Kant and Kantianism - Mathematics and Psychologism interesting story about what makes us able to think about maths, not what maths is about and what makes mathematical statements true. In the same way, my mind must be built a certain way for me to identify badgers but you don t ask a psychologist to tell you about badgers. Page 89/109

90 Chapter 13: Linguistic Relativism and Conceptual Schemes - Introduction Chapter 13: Linguistic Relativism and Conceptual Schemes Introduction Before Kant, the assumption was that there was a world out there that we could learn about. The Rationalists thought that reason could go beyond the sensory surfaces of things and discover the deep nature of reality. The Empiricists believed that we could not bypass experience as all our knowledge must begin with the deliverances of the senses but that our powerful faculty of reason could manipulate the data and make philosophical discoveries. By limiting our knowledge to sensory ideas, though, scepticism was not far away, as Hume boldly pointed out. Kant s revolutionary idea was to suggest that the world does not simply shape an open mind but that the mind shapes the world. More precisely, Kant argued that the mind had to contain software in order for experience to be possible. Had we no software, we d have no way of organising experiences and knowledge would be impossible. That we clearly do have coherent experiences and knowledge shows that our minds must be organising the raw data of experience. I have used the analogy of a computer to express Kant s idea. The software (a priori concepts) needs to be applied to the input (raw data of experience) in order for any processing to happen (for knowledge to result). Let us re-label the software as a conceptual scheme. A person s conceptual scheme is then the network of a priori concepts that shape the raw data or raw content of experience. It is shaped or conceptualised by the application of concepts to yield conceptual content. So, for Kant, it is because I possess the a priori concept of an object that the data that enters my eyes data concerning coloured surfaces, remember is shaped into an experience of objects. Were I to lack that element of my conceptual scheme, I would not experience a world of objects. I would be unable to think in terms of objects. I would simply see a shifting mass of colours. Linguistic Conceptual Schemes Kant thought that all minds had a single basic conceptual scheme. We all start off with the same basic software. We all see the world the same way. The a priori knowledge we can discover is the same for all of us. Of course, we learn different concepts as we grow up. Kant didn t have the concept of an ipod and many people today don t have the concept of a landau. But these are what we might call a posteriori concepts ones we genuinely gain from our (differing) experiences. It didn t take long before philosophers such as Johann Gottfried Herder ( ) and Wilhelm von Humboldt ( ) rejected this claim. They wondered whether one s conceptual scheme might (in part) be learned and hence reflect one s culture and/or language. 1 In the 20 th century, the idea became the Sapir-Whorf hypothesis according to which one s conceptual scheme is fixed by one s language. It is important to see what might be meant by these claims if we take them to their extremes. Let us suppose, to take the famous example, that your language contains two words, śnieg and neige, for two types of snow whereas my language contains just the one, snow. It would mean that whereas I think about all snow in the same way, you think in terms of two different types of snow. You would be able to divide up snow into śnieg-snow and neige-snow and I would simply see just snow. An analogy with colour-blindness is apposite. If I am red-green colour blind then I will see distinct colours as the same colour. Nothing you can do can make me see the difference. Similarly, unless I learn your language, I will be blind to the two different types of snow. At the very extreme, one might hold that languages can only be learned in childhood and/or through being immersed in a culture for a long time, in which case I might not ever be able to see the world your way. Page 90/109

91 Chapter 13: Linguistic Relativism and Conceptual Schemes - The Sapir-Whorf Hypothesis The Sapir-Whorf Hypothesis Whorf argued for an extreme view. In a much-quoted passage, he writes: We dissect nature along lines laid down by our native language. The categories and types that we isolate from the world of phenomena we do not find there because they stare every observer in the face; on the contrary, the world is presented in a kaleidoscope flux of impressions which has to be organized by our minds and this means largely by the linguistic systems of our minds. We cut nature up, organize it into concepts, and ascribe significances as we do, largely because we are parties to an agreement to organize it in this way an agreement that holds throughout our speech community and is codified in the patterns of our language [...] all observers are not led by the same physical evidence to the same picture of the universe, unless their linguistic backgrounds are similar, or can in some way be calibrated. (Whorf (1956) Language, Thought and Reality.) Whorf studied Native American Indian languages, notably Hopi and Apache. He was fascinated by the grammar, which was radically different to those of familiar Indo-European languages. He argued that the Apache translation of the sentence It is a dripping spring was As water, or springs, whiteness moves downwards. Apaches seem to focus on the quality of whiteness in motion. English focus on the substance water. Does this reflect a big difference? No. At least, not without much more careful research. All Whorf had done was observe that translation is best not done literally. Here s a less exotic example. If I say, Steve broke his leg in French and Polish, I say: Steve s est cassé la jambe = Steve himself is broken the leg. Steve złamał sobie nogę = Steve broke to himself a leg. The literal translations at least, these are ways of translating them literally sound silly. In both cases, one could infer that French and Polish speakers don t really distinguish their limbs as theirs because they don t say Steve est cassé sa jambe or Steve złamał swoją nogę. Moral #1: You don t translate a foreign language by importing grammatical presuppositions from your own ones. The right thing to do is to find out what speakers mean by the words that they use. Don t think people must mean something different i.e. think differently just because they use words differently! Words and Concepts The Great Eskimo Vocabulary Hoax is the story that Eskimos have lots of words for snow. They don t. Or, rather, they do depending on how you count words. The Inuit languages are polysynthetic generate very long words by sticking word-bits together whereas we have them as separate. If English were polysynthetic, we could create words such as newsnow, oldsnow, dangeroussnow and so on. Having lots of words tells us nothing about the underlying concepts. So, what about the concepts? Well, so what if they do have lots of snow-concepts. We can distinguish freshly fallen snow from pack ice from hail from slush from and so on. We have a wonderful capacity to make ever finer distinctions when circumstances demand. Consider any profession or discipline and its expert vocabulary. As someone utterly incapable of doing any kind of DIY, If I walk into B&Q, I see paint brushes and screws and nails and so forth. An expert may distinguish twenty types of brushes, thirty different types of screw, and so on. Moreover, I could in principle learn the language and come to be just as familiar with the differences that I am currently blind to. But, let us be clear, not too blind to. Show me a range of brushes and I ll see that they are different. I will simply not know what to call them because I don t know what the importantly different uses are. Page 91/109

92 Chapter 13: Linguistic Relativism and Conceptual Schemes - Is the Sapir-Whorf Hypothesis Just Nonsense, Then? Moral #2: Words aren t important it s concepts that count. Moral #3: Concepts are cheap we invent them all the time. Moral #4: We can learn each other s ordinary and technical languages. Is the Sapir-Whorf Hypothesis Just Nonsense, Then? No. There s not really a single clear hypothesis, so it would be unfair to give a yes/no answer. What we can say are the following: 1. Having a word for it makes it easier to think about it. 2. The choice of words matters. Point 1: A Name For It People who make paints and fabrics have lots of names for very precise shades of colour. Suppose Alf and Bernard have to learn to identify ten shades of red. Alf is given a colour-chart without names and Bernard one with names. There is evidence to suggest that Bernard will do better on colour-recognition tests because he can label his concepts. Another example concerns mathematics. It would be impossible to do mathematics to any remotely sophisticated level without names for the numbers (number-concepts). For a modern example of making the point, consider the power notation. Until we could express numbers like thus, talking about them would require us to consider a billion billionbillionbillionbillion billion.etc. In his book 1984, George Orwell imagines a highly-regimented form of English called Newspeak. The idea is that if a language fails to contain words for concepts the ruling powers don t want people to think about, such as freedom and democracy, then people will not be able to think about them. Of course and this was Orwell s point language doesn t constrain the range of our thoughts so tightly. If it did, we d still be speaking the languages we spoke thousands of years ago and be just about as sophisticated. We invent things and concepts for them: e.g. computer, laser, mug, spaghetti, democracy, darts and ipods. Point 2: The Choice of Words We are all very familiar with how the choice of words can affect how people think. Were the IRA terrorists? Or freedom fighters? When soldiers from different armies fighting on the same side accidentally shoot each other, is this an unfortunate case of manslaughter? Or friendly fire? When country A attacks country B before country B has attacked A, is this an act of war or a pre-emptive strike? When innocent people die in war are they innocent people killed, the (unavoidable) casualties of war or just collateral damage? Newspapers and politicians choose their words carefully so as to form opinions in the minds of their audience. This brings us to the issue of political correctness. For some, finding the right word is a matter of showing respect. For others, it is a pointless exercise because by changing the words but not the underlying issue one has achieved only a cosmetic change. For example, consider the word spastic. In the 1970s, the Spastics Society was well-known a disability charity. It has now changed its name to Scope. Why? Scope explained themselves thus: Though correct in a medical sense, in everyday use the word spastic had become a misused, unpleasant, offensive word and was frequently used as a term of abuse not only in the playground, but more seriously by adults. 2 Scope were under no illusion that changing the name would stop negative attitudes towards disabled people but the name was not helping. More recently, there has been a debate on whether children should ever be classified as obese. Some have argued that they will be stigmatised by others and develop low self-esteem. Others have argued that there is no point in dodging the issue: they should be classified as Page 92/109

93 Chapter 13: Linguistic Relativism and Conceptual Schemes - Untranslatable Words? obese because they are and given appropriate treatment. Similar sensitive issues arise with racial terms (consider your reactions to hearing someone described as a negro, coloured, and black), gender terms (consider the difference between Ms. and Miss) and terms relating to sexual orientation (consider the difference between queer, gay and homosexual.) Untranslatable Words? If the Sapir-Whorf hypothesis is false, then we don t all see the world the same way through sharing different languages. Does this mean that every language is intertranslatable? Yes and no. You can sometimes get the general meaning across but you have to learn the language to get the nuances. For example, there is a verb désarçonner in French which literally means to throw out of the saddle, as might happen if you failed to hold onto your horse. It has the metaphorical meaning of being confounded or unsettled, as by someone s arguments. Now, one might say that the violent image of being thrown from a horse has been lost in translation even if the general meaning has been preserved. According to a poll of translators a few years ago, the most untranslatable word is ilunga. from the Tshiluba language of the Republic of Congo. It means: a person who is ready to forgive any transgression a first time and then to tolerate it for a second time, but never for a third time. Strange Words 1. Ilunga Tshiluba (SE DR of Congo) A: The practice of wrapping someone in an ox-hide and hiding behind a waterfall in order to divine the future. 2. Zgrzytnąć (Polish) B: To comb one's hair in anger 3. Geragas (Malay) C: A person who is ready to forgive any abuse for the first time, to tolerate it a second time, but never a third time. 4. Taghairm (Gaelic) D: To arrive at a well and find no water in it. 5. Jabh (Persian) E: A beard. 6. Jeruhuk (Malay) F: Deep-set eyeballs. 7. Makahakahaka (Hawaiian) G: To stumble into a hole that is concealed by long grass. 8. Giomlaireachd(Gaelic) H: The sound of metal scraping on metal. 9. Poser un lapin à quelqu un I: The habit of dropping in at lunchtimes. 10. Gras bilongfes (Tokpisin, Papua New Guinea) J: To stand somebody up Page 93/109

94 Chapter 13: Linguistic Relativism and Conceptual Schemes - Common Worlds And Conceptual Schemes Common Worlds And Conceptual Schemes If our world is determined by our language not a universal type of mind, then what becomes of a priori knowledge? Well, a priori knowledge becomes knowledge of the grammar and structure of our language which makes the world appear as it does. Philosophy in its traditional form would disappear. For, even though Kant revolutionised it, he still thought that there was a common world our minds put us in contact with. If there are many conceptual schemes, then there is no common world for us to philosophise about. The philosopher Davidson has argued that the very idea of a conceptual scheme is simply nonsensical. Its proponents talk of the scheme organising the raw data. But you can only organise something which has structure. I can organise the people in my class on the basis of height, age, gender, and so on. So, the data can t be all that raw and unstructured. The only real sense we can give to the idea is that we have we all have the same sort of physical stimuli from the world that give us the same sorts of experience, on the basis of which we classify those experiences in different ways. But this is just what the Empiricist says about every concept and what the Rationalist says about any concept that isn t innate. It is the simple story of forming concepts by noticing similarities amongst our impressions. As we have seen, the kinds of concepts that emerge vary widely from people to people. But we can all learn each other s concepts just because we can all relate to the same common world. Davidson In More Detail If we genuinely had different conceptual schemes reflected in our language, then those languages would be incommensurable: we simply couldn t understand one another. Davidson argues that there cannot be incommensurable languages. Suppose we land on a distant planet and find people communicating in a language we don t understand. If Davidson is right, we can in principle learn each other s languages. How? We said above that you can only organise what has structure and we all have senses that give us the same sorts of structured experiences. But what about aliens on a distant planet? Let us suppose we are spacetravellers who have landed on their planet and are watching them. They will utter sounds to one another. So, we can observe the names they give to things, for example. We can test our understanding by pointing at things and seeing whether we get it right. Now, that we can do this presupposes a number of things: 1. That they and we inhabit a common world. 2. That they have senses that enable them to form experiences of and beliefs about the world. 3. That the native are rational. 4. That our natives aim to speak truthfully about the world to themselves and to us. 1. Of course we share a common world! We can interact with each other and we can interact with the things in it. (Could it be that we are all in the Matrix? Perhaps. But then we are still in a common world. So this is irrelevant at this stage.) 2. A little bit of examination of the aliens will reveal what sort of sensory apparatus they have. We can examine how the world affects them. It is vital to recognise here that our senses and mind combine to give us perceptual beliefs over which we have little choice. We cannot choose what we see or hear or taste or smell and with good reason! Since they will have evolved like us to be successful and intelligent beings, their senses must give them largely true beliefs about the world around them. So, together, we have largely true beliefs about the world although we may use entirely different sets of concepts in our beliefs. Page 94/109

95 Chapter 13: Linguistic Relativism and Conceptual Schemes - Summary 3. Intelligent beings will be rational beings. This means that they will have largely coherent beliefs. Rational beings do not believe contradictions. For example, if you (i) wake up thinking it is Tuesday and (ii) see on the television that it is Wednesday, you do not (iii) believe that it is both Tuesday and Wednesday. You seek to resolve the contradiction. So, when we confront our natives, we know that they will hold coherent beliefs. 4. Communication works on the basis that people (a) try to speak the truth and (b) do in fact typically speak the truth. (a) It would be impossible to have a community of people who always lie to one another. Lying presupposes a convention of truth-telling. In the same way, counterfeit money only works if there is real money. (b) It would be impossible to be massively in error. If you keep saying things that are false, you will stand out. You will cause other people to make mistakes. They will seek to correct you. (Could we all be in error? No. Our experiences and beliefs are in large part formed in reaction to the world. The world causes experiences in us and we automatically form beliefs about the world in response. We could be intelligent beings otherwise indeed, we couldn t even be unintelligent beings! Any creature that massively misrepresents its environment is not going to last long! 3 ) If we put all this together, then we have the following. Rational beings form largely true beliefs in response to the world. They form further beliefs by reflecting on them and the overall set must be coherent. And largely true. We could not go massively wrong with a base of largely true beliefs about the world. We share the same world. We communicate with each other about that world. Therefore, by careful observation of how people behave and speak, we can decipher each other s language. There is, therefore, no way that two languages could be radically different from one another. We share too much for this to be possible. Of course, different languages can have different concepts they express by different words think of our concept of a sandwich but this does not mean that they cannot be translated. Of course, our aliens may have very different senses from us. They may sense magnetic fields, for example. But this doesn t matter. It just means that we need to use a bit of physics and a bit of technology to help us see the world their way. Of course, we can t literally have their sensations. But in the same way colour-blind people cannot literally see colours but this is a very minor hindrance we can still communicate with colour-blind people! In conclusion, Davidson claims that because intelligent people can always find a way of communicating, their differences are shallow. There is nothing substantial meant by the division between scheme and content. It is not that there are fundamentally different ways of dividing the world. There is a single world out there (about which physics tells us the details) that we share and talk about, albeit sometimes with different vocabularies. Summary The radical idea that speakers of different languages cannot see the world in the same way is false because we can learn other languages. The almost-as-radical idea that speakers of different languages see the world in very different ways is not borne out by the evidence one we take care to translate properly. The much-less-radical idea that having a word for it makes a difference is true. The much-much-less-radical idea that what words we chose makes a difference is also true. Page 95/109

96 Chapter 13: Linguistic Relativism and Conceptual Schemes - Questions Questions 1. If you speak a foreign language, find a word that is particularly hard to translate into English. 2. Can you think of any words which were once acceptable and now are not? Do you think it matters? Or should people be less offended by mere words? 3. Are you an expert at anything? (It could be anything from watching football to buying shoes) Do you have a richer vocabulary because of it? 1 It would have to be in part because otherwise, we d be born blank slates and we d be back to the Empiricism Kant rejected because of the problem of accounting for how we organise experience at all without any software Once again, what if we are all in the Matrix? Are we not then massively in error? This is a tricky issue we cannot deal with properly here. One reaction is the bold one: we can t be massively in error (because otherwise we would not be here as intelligent beings) and hence this proves we are not in the Matrix. A second reaction is to say that we are in error but in a different way. I think there is a cup before me. I am in the Matrix. Nevertheless, my belief is true. My word cup picks out the virtual entity that the Matrix creates. We are massively in error but about what our true beliefs are. But this error is fine. For it is really a matter of being ignorant of the deep nature of reality. Consider how for many years people successfully truly talked about iron and water and the Sun and so on whilst having completely wrong theories about what they were. We would be in the same position with respect to everything. We think reality is non-matrix-like but we are wrong. See my article in the RJP, Putnam and Scepticism for more on this topic: Page 96/109

97 Chapter 14: From Logical Positivism to Quine - Introduction Chapter 14: From Logical Positivism to Quine Introduction In the 1920s, a philosophical movement sprang up which was very much a return to Empiricism. All knowledge of reality begins with experience. Our experience is not shaped by Kantian a priori concepts. Such things were always a little strange; and besides, as we have seen, it is just not true that we are forced to see space, time and reality in certain ways. More generally, by saying our mind shapes the world for us, we are cut off from reality rather than in contact with it. There s no proof that reality is anything like it seems or even there at all! Like Hume, the Logical Positivists took an axe to philosophy. We are in contact with the world through our senses. Everything we can say and think about the world is only meaningful if we say that being true or false would make a difference to our experiences. The statement it is raining is meaningful as, if true, the world will look different, than if false. But the statement there is a reality beyond all possible experience is not. True or false, everything will seem the same. But then we are not really saying anything at all. The words are empty. Like all Empiricists, they had two challenges: If all knowledge begins with experience ideas or sensations then how do you avoid scepticism? How can you get beyond ideas to say that there s anything out there at all? What are you going to say about a priori knowledge and necessary truths? What s the story about maths and science? In this chapter, we shall look at the moment and how they answer these challenges. The Verification Principle Whereas Hume talked plainly in terms of knowledge, the Logical Positivists talked in terms of meaning. If all knowledge begins with experience, we cannot know anything beyond experience. The same goes for knowledge of language. What I learn as the meanings of my words must be rooted in experience too, so that I cannot understand any word whose meaning somehow goes beyond experience. The central element to the positivist conception of knowledge can now be introduced: verifiability. If the meanings of my words are rooted in experience, then I cannot understand any sentence that talks about things that lie beyond experience. A meaningful sentence, therefore, must be one which could in principle be verified (or falsified) by the senses: the sentence It is raining is meaningful because I can verify with the senses whether it is true or false. I can look out of the window. This is because the sun refers to something I can experience. the sentence There is a reality beyond all experience is not meaningful because I cannot verify with the senses whether it is true or false. My experience would remain the same regardless of whether it is true or false. This is so for synthetic claims or those that purport to make substantial claims about reality. An analytic claim is different. The sentence a square has four sides cannot be verified by experience because its truth has nothing to do with experience. It is true because of what square means. Putting all this together, we get a revised version of Hume s fork. Any meaningful claim is either analytic or synthetic: Page 97/109

98 Chapter 14: From Logical Positivism to Quine - Knowledge and Reality Analytic An analytic sentence is true or false in virtue of what the words mean. Synthetic A synthetic sentence is one that can be verified in principle by some sort of sensory experience. A square has four sides. A bachelor is an unmarried man. If Jim is taller than Jane, then Jane is shorter than Jim. It is sunny. Paris is the capital of London. Gold conducts electricity. Analytic truths are knowable a priori. Analytic truths are necessary truths. Synthetic truths sentences are knowable a posteriori. Synthetic truths are contingent truths. Knowledge and Reality All knowledge begins with basic sensations or sense data as they were now known. (They are essentially the same thing as Locke s basic ideas and Hume s impressions.) On the basis of these meagre ingredients, we come to form concepts of things in the external world. What about the problem of scepticism? How can we know that our ideas correspond to an external world? The Logical Positivists faced the same sceptical problem as Hume: how to bridge the gap between ideas of the world and the world itself. They closed it with a phenomenalistic analysis of ordinary things. On the surface, if I say that there is a cat before me, I report how a bit of external reality is. We can t in fact mean this because we can t go beyond our ideas. So, what we really mean at a deeper level is that I am experiencing certain sense-data. Now, I may leave the room and leave the cat here. So, what does it mean to say that the cat is in the room if no-one is there to see it? Answer: the cat is in the room = if anyone were to be in the room, they would experience certain sense-data. So, when we talk about things in the world, we are really talking at a deeper level about actual and possible experiences we can have. Remember the basic thinking behind logical positivism. If it is meaningful to talk about something, it must be possible to verify with the senses whether it exists. So, all talk of things is ultimately talk about the impressions we should have of them. So, there is no sceptical gap because we get rid of the need for a mysterious world beyond causing our ideas. The need came, as Hume put it, because it sounds crazy to think of things not existing when I don t perceive them. It s just natural. But if we can translate everything we say which seems to make reference to an external world of things into statements about what we do and would perceive, then we don t need the idea of that world and the gap goes. Now, it might sound odd to say that cat-talk is really about cat-sensations but that s just because we re so familiar with the world of middle-sized objects. Consider instead something like an electron. Scientists tells us that there are such things but they are too small to be seen. Well, why believe them? What evidence is there? Were a scientist simply to say that they cannot be sensed, we would rightly be suspicious. How can they have been discovered if they can t be observed? Talk of electrons must be cashed out in terms of talk of how things seem. Page 98/109

99 Mathematical Knowledge Chapter 14: From Logical Positivism to Quine - Mathematical Knowledge According to the Logical Positivists, those troublesome necessary truths of mathematics could be explained as analytic truths after all, despite what Kant had said. Kant had simply got too narrow an understanding of analytic. Kant denied that 7+5=12 is analytic because when you understand 12, you don t find 7+5 in it. If you did, it would be plainly contradictory to deny that 7+5=12. But someone can deny it. They are wrong, of course, but they are not saying something stupid. They are making the sort of innocent mistake people make when they do maths. An analytic truth, they said, was, as Hume said, to do with the connections between ideas alone. Now, when you grasp the idea 12, you don t see 7+5 in it. Kant was right about that. But that just shows something about our psychology. The connection is there, alright, but we may need to do a bit of thinking to see it. Kant s mistake was to think that if a statement is analytic, it is obviously true only a fool would fail to agree! But don t confuse psychology and philosophy! A truth can be necessarily true in virtue of the conceptual connections and not be obvious at all. It is a necessary mathematical truth that there is no largest prime number but it is not immediately obvious. Quine s Web Of Belief Logical Positivism came under attack in the 1940s and 1950s and sank pretty much without trace. One of the key attacks was launched by the philosopher Quine. Quine argued for something quite radical. There is no analytic/synthetic distinction and here is no a priori/a posteriori distinction either. We will focus on one part of what he said. Remember that an analytic sentence is meant to be a truth of definition or tautology. We can think of them as defining one concept in terms of another. So, we might have: A bachelor is an unmarried man. A mammal is a warm-blooded creature with hair that gives birth to live young. These truths are supposedly necessary and hence unrevisable. But who knows what we ll discover? The discovery of the duck-billed platypus was a surprise because it was warm-blooded, had hair but laid eggs. So, it isn t by definition a mammal. But perhaps the definition is no good. Perhaps we should revise it. Or perhaps we should keep it as it is and invent a new label for such creatures. Quine s point is that there s no right answer here. We should do what gives us the best overall theory of the world. So, if no sentence can be put in a box as never to be touched or revised! then no sentence is analytic. And thus no sentence is synthetic either. And thus no sentence can be known a priori as to know whether p is true, we need to consult our best overall theory of the world. Most immune to revision: necessary, a priori, analytic. Least immune to revision: contingent, a posteriori, synthetic. Quine said that we should reject the sharp division for a picture of a web. At the centre of the web are those truths that are most secure. For example, we find here our basic mathematical beliefs. As we move Page 99/109