Plato The most famous of Socrates's pupils was an aristocratic young man named Plato. After the death of Socrates, Plato carried on much of his former teacher's work and eventually founded his own school, the Academy, in 385. The Academy would become in its time the most famous school in the classical world, and its most famous pupil was Aristotle. We know much about Plato's teachings, because he wrote dialogues between Socrates and others that would explore philosophical issues. These dialogues would be used in his school as starting points for discussion; these discussions and Plato's final word on the dialogues have all been lost to us. The Platonic dialogues consist of Socrates asking questions of another and proving, through these questions, that the other person has the wrong idea on the subject. Initially, Plato seems to have carried on the philosophy of Socrates, concentrating on the dialectical examination of basic ethical issues: what is friendship? what is virtue? can virtue be taught? In these early Platonic dialogues, Socrates questions another person and proves, through these questions, that the other person has the wrong idea on the subject. These dialogues never answer the questions they begin with. However, Plato later began to develop his own philosophy and the Socrates of the later dialogues does more teaching than he does questioning. The fundamental aspect of Plato's thought is the theory of "ideas" or "forms." Plato, like so many other Greek philosophers, was stymied by the question of change in the physical world. Heraclitus had said that there is nothing certain or stable except the fact that things change, and Parmenides and the Eleatic philosophers claimed that all change, motion, and time was an illusion. Where was the truth? How can these two opposite positions be reconciled? Plato ingeniously combined the two; a discussion of Plato's theory of forms is below. The most famous of Plato's dialogues is an immense dialogue called The Republic, and, next to his account of Socrates trial, The Apology, The Republic is one of the single most influential works in Western philosophy. Essentially, it deals with the central problem of how to live a good life; this inquiry is shaped into the parallel questions (a) what is justice in the State, or what would an ideal State be like, and (b) what is a just individual? Naturally these questions also encompass many others, such as how the citizens of a state should be educated, what kinds of arts should be encouraged, what form its government should take, who should do the governing and for what rewards, what is the nature of the soul, and finally what (if any) divine sanctions and afterlife should be thought to exist. The dialogue, then, covers just about every aspect of Plato's thought. There are several central aspects to the dialogue that sum up Platonic thought extremely well: a.) what the nature of justice is; b.) the nature of an ideal republic; and c.) the allegory of the cave and the divided line, both of which explain Plato's theory of forms. The Nature of Justice. The question which opens this immense dialogue is: what is justice? Several inadequate definitions are put forward, but the most emphatically presented definition is given by a young Sophist, Thrasymachus. He defines justice as whatever the strongest decide it is, and that the strong decide that whatever is in their best interest is just (review again the Athenian position in Melian Debate). Socrates dismisses this argument by proving that the strong rarely figure out what is in their best interest, and this can't be just since justice is a good thing. The Analogy of the Ideal Republic. After Thrasymachus leaves in a royal huff, Socrates starts the question all over again. If one could decide what a just state is like, one could use that as an analogy for a just person. Plato then embarks on a long exposition about how a state might embody the four great virtues: courage, wisdom, temperance, and justice. The remainder of the dialogue is a long exposition of what justice in a state is; this section is considered one of the first major, systematic expositions of abstract political theory. This type of thinking, that is, speculating about an ideal state or republic, is called "utopian" thinking (utopia is a Greek word which means "no-place"). Plato (speaking through Socrates) divides human beings up based on their innate intelligence, strength, and courage. Those who are not overly bright, or strong, or brave, are suited to various productive professions: farming, smithing, building, etc. Those who are somewhat bright, strong, and especially courageous are suited to defensive and policing professions. Those who are extraordinarily intelligent, virtuous, and brave, are suited to run the state itself; that is, Plato's ideal state is an aristocracy, a Greek word which means "rule by the best." The lower end of human society, which, as far as Plato is concerned, consists of an overwhelming majority of people in a state, he calls the "producers," since they are most suited for productive work. The middle section of society, a smaller but still large number of people, make up the army and the police and are called "Auxiliaries." The best and the brightest, a very small and rarefied group, are those who are in complete control of the state permanently; Plato calls these people "Guardians." In the ideal state, "courage" characterizes the Auxiliaries; "wisdom" displays itself in the lives and government of the Guardians. A state may be said to have "temperance" if the Auxiliaries obey the Guardians in all things and the Producers obey the Auxiliaries and Guardians in all things. A state may be said to be intemperate if any of the lower groups do not obey one of the higher groups. A state may be 1
said to be just if the Auxiliaries do not simply obey the Guardians, but enjoy doing so, that is, they don't grumble about the authority being exercised over them; a just state would require that the Producers not only obey the Auxiliaries and Guardians, but that they do so willingly. When the analogy is extended to the individual human being, Plato identifies the intellect with the Guardians, the spirit or emotions with the Auxiliaries, and the bodily appetites with the Producers. Therefore, an individual is courageous if his or her spirit is courageous and an individual is wise if his or her intellect is wise. Temperance occurs when the emotions are ruled over by the intellect, and the bodily appetites are ruled over by the emotions and especially the intellect. An individual may be said to be just when the bodily appetites and emotions are not only ruled over by the intellect, but do so willingly and without coercion. Does this arrangement satisfy you? Is this a fair division of the human soul? Is this a fair division of society? Before you even read Plato's critique of democracy, what do you think he would say about it? Would a democratic state be courageous, wise, temperate, and just based on the system Plato sets up here? What would Plato think of American democracy, which is based on elected representatives? What is the "democratic individual" and how does this creature come about? What happens to individuals in a democracy? existing on a line that can be divided in the middle: the lower part of the line consists of the visible world and the upper part of the line makes up the intelligible world. Each half of the line relates to a certain type of knowledge: of the visible world, we can only have opinion (in Greek: doxa); of the intelligible world we achieve "knowledge" (in Greek, epistemž). Each of these divisions can also be divided in two. The visible or changing world can be divided into a lower region, "illusion," which is made up of shadows, reflections, paintings, poetry, etc., and an upper region, "belief," which refers to any kind of knowledge of things that change, such as individual horses. "Belief" may be true some or most of the time but occasionally is wrong (since things in the visible world change); belief is practical and may serve as a relatively reliable guide to life but doesn't really involve thinking things out to the point of certainty. The upper region can be divided into, on the lower end, "reason," which is knowledge of things like mathematics but which require that some postulates be accepted without question, and "intelligence," which is the knowledge of the highest and most abstract categories of things, an understanding of the ultimate good. The Allegory of the Cave and the Divided Line: Far and away the most influential passage in Western philosophy ever written is Plato's discussion of the prisoners of the cave and his abstract presentation of the divided line. For Plato, human beings live in a world of visible and intelligible things. The visible world is what surrounds us: what we see, what we hear, what we experience; this visible world is a world of change and uncertainty. The intelligible world is made up of the unchanging products of human reason: anything arising from reason alone, such as abstract definitions or mathematics, makes up this intelligible world, which is the world of reality. The intelligible world contains the eternal "Forms" (in Greek, idea ) of things; the visible world is the imperfect and changing manifestation in this world of these unchanging forms. For example, the "Form" or "Idea" of a horse is intelligible, abstract, and applies to all horses; this Form never changes, even though horses vary wildly among themselves the Form of a horse would never change even if every horse in the world were to vanish. An individual horse is a physical, changing object that can easily cease to be a horse (if, for instance, it's dropped out of a fifty story building); the Form of a horse, or "horseness," never changes. As a physical object, a horse only makes sense in that it can be referred to the "Form" or "Idea" of horseness. Plato imagines these two worlds, the sensible world and the intelligible world, as 2
Aristotle Aristotle represents for most of us an icon of difficult or abstruse philosophical thinking; to know Aristotle often provokes hushed whispers even from highly educated people. For all this reputation, though, Aristotle is actually quite an easy read, for the man thought with an incredible clarity and wrote with a superhuman precision. It really is not possible to talk about Western culture (or modern, global culture) without coming to terms with this often difficult and often inspiring philosopher who didn't get along with his famous teacher, Plato, and, in fact, didn't get along with just about everybody (no-one likes a know-it-all). We can say without exaggeration that we live in an Aristotelean world; wherever you see modern, Western science dominating a culture in any meaningful way (which is just about everywhere), Aristotle is there in some form. Aristotle was born at Stagira, in Thrace, in 384 B.C. His father was a physician to the king of Macedon, so science was in his background. At the age of seventeen, he went to Athens and joined Plato's school, where he stayed until Plato's death in 347. A few years later, he became the tutor to the young prince of Macedon, Alexander the Great. Although Alexander was a stellar pupil, Aristotle returned to Athens three years later, founded his own school, the Lyceum, and taught and studied there for twelve years. Because Alexander began conquering all of the known world, Macedonians became somewhat unwelcome in Athens and Aristotle was accordingly shown the door in 323. He died a year later. Although he studied under Plato, Aristotle fundamentally disagreed with his teacher on just about everything. He could not bring himself to think of the world in abstract terms the way Plato did; above all else, Aristotle believed that the world could be understood at a fundamental level through the detailed observation and cataloging of phenomenon. That is, knowledge (which is what the word science means) is fundamentally empirical. As a result of this belief, Aristotle literally wrote about everything: poetics, rhetoric, ethics, politics, meteorology, embryology, physics, mathematics, metaphysics, anatomy, physiology, logic, dreams, and so forth. We aren't certain if he wrote these works directly or if they represent his or somebody else's notes on his classes; what we can say for certain is that the words, "I don't know," never came out of his mouth. In addition to studying everything, Aristotle was the first person to really think out the problem of evidence. When he approached a problem, he would examine a.) what people had previously written or said on the subject, b.) the general consensus of opinion on the subject, c.) and a systematic study of everything else that is part of or related to the subject. In his treatise on animals, he studied over five hundred species; in studying government, he collected and read 158 individual constitutions of Greek states as his fundamental data. This is called inductive reasoning: observing as many examples as possible and then working out the underlying principles. Inductive reasoning is the foundation of the Western scientific method. Outside of the empirical method, three characteristics stand out in Aristotle's thought: the schematization of knowledge, the four causes, and the ethical doctrine of the mean. The Classification of Knowledge. Perhaps the most fundamental aspect of Aristoteleanism is the classification of knowledge according the objects of that knowledge. The Greeks for some time had been concerned about the nature of human knowledge; this concern is called epistemology, or the "study of knowledge." For a long time, Greek philosophy dealt with questions of certainty; how could one be certain of knowledge? Suppose everything was an illusion? Aristotle sorted knowledge into two categories: physics (that which can be explained precisely) and metaphysical (that which had no precise answers). For instance, certain objects (such as in mathematics or logic) permit you to have a knowledge that is true all the time (two plus two always equals four). These types of knowledge are characterized by certainty and precise explanations. Other objects (such as human behavior) don't permit certain knowledge (if you insult somebody you may not make them angry or you may make them angry). These types of knowledge are characterized by probability and imprecise explanations. Knowledge that would fall into this category would include ethics, psychology, or politics. Unlike Plato and Socrates, Aristotle did not demand certainty in everything. One cannot expect the same level of certainty in politics or ethics that one can demand in geometry or logic. In Ethics I.3, Aristotle defines the difference in the following way, "we must be satisfied to indicate the truth with a rough and general sketch: when the subject and the basis of a discussion consist of matters which hold good only as a general rule, but not always, the conclusions reached must be of the same order.... For a well-schooled man is one who searches for that degree of precision in each kind of study which the nature of the subject at hand admits: it is obviously just as foolish to accept arguments of probability from a mathematician as to demand strict demonstrations from an 3
orator." The Four Causes. If you walk out of this class knowing anything really well, it should be this, for Aristotle's "four causes" stand at the heart of Western rationality and Western science. In order to know a thing, anything at all, Aristotle says that one must be able to answer four questions (Physics ). Plato looked at the world and saw nothing but change; he wondered how we can know anything at all when everything is in motion and change. Plato solved the problem by postulating an unchanging world of intelligible Forms or Ideas of which our world is but an imperfect copy. But Aristotle embraced the visible world of change and motion and sought all his life to describe the principles which bring about change and motion. Therefore, the question that dominated his thought at all points was: 1) what is the cause (in Greek, aitia, which also means "responsible factor" of this particular change or motion that I'm observing? 2) What causes this thing to come into existence? 3) What causes it to pass out of existence? 4) What is the purpose of this thing based on its effect and its origin? Aristotle was the first major thinker to base his thought and science entirely on the idea that everything that moves or changes is caused to move or change by some other thing. What causes motion and change in the universe? The four causes: a.) the material cause: the matter out of which a thing is made (clay is the material cause of a bowl); b.) the formal cause: the pattern, model, or structure upon which a thing is made (the formal cause of a bowl is "bowl-shaped"; the formal cause of a human is "human-shaped"); c.) the efficient cause: the means or agency by which a thing comes into existence (a potter is the efficient cause of a bowl); d.) the final (in Greek, telos ) cause: the goal or purpose of a thing, its function or potential (holding cereal and milk is the final cause of a bowl). The final cause is the most unscientific, but is far and away the most important "cause" of a thing as far as Aristotle was concerned. Aristotle's analysis of phenomenon and change, then, is fundamentally teleological. Aristotle's thought is consistently teleological: everything is always changing and moving, and has some aim, goal, or purpose (telos ). To borrow from a Newtonian physics, we might say that everything has potential which may be actualized (an acorn is potentially an oak tree; the process of change and motion which the acorn undertakes is directed at realizing this potential). The Doctrine of the Mean. The Four Causes are universally applicable. However, ethics is a science that admits of a high degree of uncertainty because of the infinite variety of human actions and motivations. Now, normally ethics seems to require absolute and unchanging principles ("Thou shalt not kill") which individuals depart from at their peril. The idea that ethics are "man-made" is a problematic idea (see the discussion of the Sophists in the Pre-Socratics chapter); the idea that it is the individual situation which dictates whether an action is right or wrong is, at least to early human society, downright revolutionary. But this is what Aristotle concluded and it fits in perfectly with his general empirical temperament. He works out an entire system of ethics based on the "mean" to serve as a guideline to human behavior. There is no proper definition of any moral virtue, but rather every moral virtue stands in relationship to two opposing vices. Take courage. Courage is the opposite of cowardice. But, it is also the opposite of foolhardiness. Somewhere between foolhardiness and cowardice, that's where courage lies. What constitutes this "mean" between the two terms varies from situation to situation: what is courageous in one situation may be cowardly in another; what is foolhardy in one situation may be courageous in another. Therefore, every action needs to be judged according to all the relevant circumstances and situation. Aristotle called judging actions in this manner, "equity," and equity is the foundation of modern law and justice, and is absolutely critical in understanding foundational Christianity and its later permutations, such as the Protestant Reformation. But that's a story for another day. 4
William of Ockham William of Ockham The principle of simplicity is the central theme of Ockham s approach, so much so that this principle has come to be known as Ockham s Razor. Ockham uses the razor to eliminate unnecessary theories. In metaphysics, Ockham is a Nominalist, the view that universal essences, such as humanity or whiteness, are nothing more than concepts in the mind. Okham s Razor Ockham s Razor says the simplest theory must be the right one ; for some, the principle of simplicity implies that the world is simple. For Ockham, It is useless to do with more what can be done with less, Ockham implies that theories are meant to explain and predict, and these things can be accomplished more effectively with fewer assumptions. At one level, this is just common sense. Suppose your car suddenly stops running and your fuel gauge indicates an empty gas tank. It would be silly to hypothesize both that you are out of gas and that you are out of oil. You need only one hypothesis to explain what has happened. Some would object that the principle of simplicity cannot guarantee truth. The gas gauge on your car may be broken or the empty gas tank may be just one of several things wrong with the car. In response to this objection, one might point out that the principle of simplicity does not tell us which theory is true but only which theory is more likely to be true. Moreover, if there is some other sign of damage, such as a blinking oil gage, then there is a further fact to explain, warranting an additional hypothesis. At bottom, Ockham advocates simplicity in order to reduce the risk of error. Every hypothesis carries the possibility that it may be wrong. The more hypotheses you accept, the more you increase your risk. Ockham strove to avoid error at all times, even if it meant abandoning well-loved, traditional beliefs. This approach helped to earn him his reputation as destroyer of the medieval systems of belief. Nominalism One of the most basic challenges in metaphysics is to explain how it is that things are the same despite differences. The Greek philosopher Heraclitus (540 480 B.C.E.) points out that you can never step into the same river twice, referring not just to rivers, but to places, people, and life itself. Every day everything changes a little bit and everywhere you go you find new things. Heraclitus concludes from such observations that nothing ever remains the same. All reality is constantly changing. The problem with seeing the world this way is that it leads to radical skepticism: if nothing stays the same from moment to moment and from place to place, then we can never really be certain about anything. We can t know our friends, we can t know the world we live in, we can t even know ourselves! Moreover, if Heraclitus is right, it seems science is impossible. We could learn the properties of a chemical here today and still have no basis for knowing its properties someplace else tomorrow. Needless to say, most people would prefer to avoid skepticism. It s hard to carry on in a state of complete ignorance. Besides, it seems obvious that science is not impossible. Studying the world really does enable us to know how things are over time and across distances. The fact that things change through time and vary from place to place does not seem to prevent us from having knowledge. From this, some philosophers, such as Plato and Augustine (354-430), draw the conclusion that Heraclitus was wrong to suppose that everything is in flux. Something stays the same, something that lays underneath the changing and varying surfaces we perceive, namely, the universal essence of things. For example, although individual human beings change from day to day and vary from place to place, they all share the universal essence of humanity, which is eternally the same. Likewise for dogs, trees, rocks, and even qualities there must be a universal essence of blueness, heat, love, and anything else one can think of. Universal essences are not physical realities; if you dissect a human being, you will not find humanity inside like a kidney or a lung! Nevertheless, universal essences are metaphysical realities: they provide the invisible structure of things. Belief in universal essences is called metaphysical realism, because it asserts that universal essences are real even though we cannot physically see them. Although there are various different versions of metaphysical realism, they are all designed to secure a foundation for knowledge. It seems you have a choice: either you accept metaphysical realism or you are stuck with skepticism. Ockham, however, argues that this is a false dilemma. He rejects metaphysical realism and skepticism in favor of nominalism: the view that universal essences are concepts in the mind they are a way to understand what we encounter, but just because we understand them doesn t make them real. Ockham developed a more sophisticated version of nominalism often called conceptualism because it holds that universal essences are concepts caused in 5
our minds when we perceive real similarities among things in the world. For example, when a child comes in contact with different human beings over time, he begins to form the concept of humanity. The realist would say that he has detected the invisible common structure of these individuals. Ockham, in contrast, insists that the child has merely perceived similarities that fit naturally under one concept. Ockham has a much deeper worry about realism: Ockham asserts that metaphysical realism cannot be true because it holds that a universal essence is one thing and many things at the same time. The form of humanity is one thing, because it is what all humans have in common, but it is also many things because it provides an invisible structure of each individual one of us. This is to say that it is both one thing and not one thing at the same time, which is a contradiction. In other words, if everyone shares the same color skin, we call that Caucasian, but not every Caucasian looks alike, acts alike, or thinks alike. The element that ties them together (their Whiteness) has not bearing on their individual behavior. There is nothing essential about being white other than being white. If you destroy one white person, it has not bearing on another, so it cannot be an essential reality. Epistemology Epistemology is the study of knowledge: There are two basic approaches to epistemology: Rationalists claim that knowledge comes through reason; Empiricists claim knowledge comes through experience, observation, and study. Ockham says we are born blank states: we learn by observing qualities in objects. Ockham s version of empiricism is called direct realism because he denies that there is any intermediary between the perceiver and the world. Direct realism states that if you see an apple, its redness causes you to know that it is red. Ockham uses the apple example to demonstrate his four-step process of knowledge acquisition: Step One - Sensory Awareness: receiving data through the five senses. This is an ability human beings share with animals; we see things, and we make sense out of them. Step Two Intuition: making sense out of how we should react with information. This is unique to human beings; animals see things and react, humans see things and manipulate the outcome. teach us how to interact and approach different situations. This is different from Intuition because it involves thinking, reasoning, and responding. Step Four - Connecting Abstractions: making sense of all our information by classifying the information and making connections between all their parts. Empiricism does this; they find all the connections between two related objects and label them for the sake of understanding: for instance, what is the difference between a fruit and a vegetable? Both grow in the ground, but they have different properties. Notice that, if an apple is set in front of a horse, the horse will receive data about the apple the color, the smell, etc. and react appropriately. The horse will not, however, register the reality of the object. Suppose you project a realistic, laser image of an apple in front of the horse and he tries to take a bite. He will become frustrated, and eventually give up, but he will never really get it. Human beings, in contrast, have reality-sensitive minds. It s not a matter of thinking This is real every time we see something. On the contrary, Ockham asserts that intuitive cognition is non-propositional. Rather, it is a matter of registering that the apple really has the qualities we perceive. Ockham writes: In normal adult human perception, all four of the above steps happen together so quickly that it is hard to separate them. But try to imagine what perception is like for a toddler: she sees the round, red object and points to it saying That! This is an expression of intuition; she recognizes it as an individual thing, though she does not have the words to describe it. Intuition secures a causal link between the external world and the human mind. The human mind is entirely passive, according to Ockham. Objects in the world cause us to be aware of their existence, and this explains and justifies our belief in them. As we have seen, Ockham argues each object in the world is an absolute individual and that is how we perceive it at first. Just like toddlers, we are bombarded with a buzzing, booming confusion of colors and sounds. But our minds are powerful sorting machines. We remember perceptions over time (memory) and organize them into groups (abstract). This organizational process gives us a coherent understanding of the world and is what Ockham aims to explain in his account of logic. Step Three Memory: creating mental maps of information that 6