Contents EMPIRICISM. Logical Atomism and the beginnings of pluralist empiricism. Recap: Russell s reductionism: from maths to physics

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1 Contents EMPIRICISM PHIL3072, ANU, 2015 Jason Grossman lecture 9: 22 September Recap Bertrand Russell: reductionism in physics Common sense is self-refuting Acquaintance versus description Logical atomism Differences between Idealism and Phenomenalism Logical Atomism and the beginnings of pluralist empiricism Recap: Russell s reductionism: from maths to physics There are many possible ways of turning some things hitherto regarded as real into mere laws concerning the other things. Obviously there must be a limit to this process, or else all the things in the world will merely be each other s washing Bertrand Russell, The Analysis of Matter, 1927, p. 325 Note the PLURALISM: this is new. Recap: The impact of Einstein on Russell Recall dates: Einstein s Special Relativity was 1905 and his General Relativity was According to Einstein, each event had to each other a relation called interval, which could be analysed in various ways into a time element and a space element. The choice between these various ways was arbitrary, and no one of them was theoretically preferable to any other.... What has been thought of as a particle will have to be thought of as a series of events.... Thus "matter" is not part of the ultimate material of the world, but merely a convenient way of collecting events into bundles.... Quantum theory reinforces this conclusion Bertrand Russell, History of Western Philosophy, p. 832 This is a rejection of the ontologies of both substances and objects. See how what was speculative in Hume and Berkeley has now been endorsed as science by Einstein (who read Hume and Berkeley). Recap: Sometimes I just hate terminology Russell sometimes referred to his version of empiricism as phenomenalism, and sometimes as logical atomism, especially The details kept changing. I m going to focus on Russell s description of phenomenalism in Our Knowledge of the External World from 1914, and his description of logical atomism in Logical Atomism from 1924; but see The Relation of Sense-data to Physics (1917) for his views on materialism. Carnap s detailed version of phenomenalism, in Der Logische Aufbau Der Welt, 1928, was not atomistic. Russell distinguished between: 1. sense-data, which are our sensations = Locke s phenomena = Hume s impressions 2. sensibilia, which are potential sense-data Recap: Sense and sensibilia Russell often (not always) treated sensibilia as material (in Berkeley s sense): What the mind adds to sensibilia, in fact, is merely awareness: everything else is physical or physiological. Bertrand Russell, The Relation of Sense-data to Physics, in Mysticism and Logic, London: George Allen & Unwin, 1917; reprinted in Totowa, New Jersey: Barnes & Noble Books, 1951, pp p.110 Some historians see this as the beginning of Russell s neutral monism. The one thing that is absolutely consistent in Russell s treatment of materialism is his ambivalence! Later empiricists generally rejected material sensibilia, although not (usually) material objects.

2 Recap: Logicist reductionism logicism: the reduction of mathematics to logic... + definitions... + maybe other general principles. Does not necessarily deny the objective reality of mathematical objects (and, in Frege, strongly affirms it). Logicism is pluralist: it can also be worked out in various different ways. Recap: Phenomenalist reductionism phenomenalism: the reduction of all knowledge to sensibilia + logic... + definitions... + maybe other general principles such as the principle of logical analysis itself! Does not necessarily deny the objective reality of physical objects but does say that objects are parasitic on sensibilia. Phenomenalism is pluralist: it can be worked out in various different ways. Russell s phenomenalism Step 1. The distinction between hard and soft data. Hard data: those which resist the solvent influence of critical reflection. Bertrand Russell, Our Knowledge of the External World as a Field for Scientific Method in Philosophy, London: George Allen & Unwin, 1914, pp This is a matter of degree. What does not go beyond our own personal sensible acquaintance must be for us the most certain. Our Knowledge of the External World, p. 74 Russell s phenomenalism Step 2. Testimony comes from relatively soft data about other minds. This means that almost all our knowledge is soft. The belief that [tables and chairs] persist is, in all men [sic] except a few philosophers, logically primitive, but it is not psychologically primitive... we feel that some kind of argument must be produced... We do not feel this as regards the immediate objects of sense Our Knowledge of the External World, p. 77 A belief being not psychologically primitive means that it needs justification... & it can t be justified by common sense because common sense is self-refuting! Common sense is self-refuting common sense leaves us completely in the dark as to the true intrinsic nature of physical objects The Problems of Philosophy, p. 53 We all start from naive realism, i.e., the doctrine that things are what they seem. We think that grass is green, that stones are hard, and that snow is cold. But physics assures us that the greenness of grass, the hardness of stones, and the coldness of snow, are not the greenness, hardness, and coldness that we know in our own experience, but something very different.... Naive realism leads to physics, and physics, if true, shows that naive realism is false. Betrand Russell, An Inquiry Into Meaning and Truth, New York: Norton, 1940, p. 15 Acquaintance and description So... Step 3. The hardest data about physical objects are aspects, which are sets of sensations. Step 4. Replacement of objects by sets of aspects..

3 Knowledge by acquaintance Definition: We shall say that we have acquaintance with anything of which we are directly aware, without the intermediary of any process of inference or any knowledge of truths. 1912, p. 73 What I know by acquaintance: Russell patterns in my visual field some simple relations e.g., before universals, i.e. abstract ideas ( whiteness, diversity, brotherhood, and so on [and] all verbs ) memories introspection the self... maybe 1912, p. 81 What I know by acquaintance: Carnap (and Ayer) Gestalt psychology Gestalts comprising a sort of snap shot of a given time of everything perceived viewed i.e. not atomism... note that perceptions can overlap. Carnap s view is much more accurate psychologically but we ll concentrate on Russell s view (even though he was wrong) because doing this properly is so complicated. "Grey square optical illusion" by Original by Edward H. Adelson, this file by Gustavb - File created by Adrian Pingstone, based on the original created by Edward H. Adelson Knowledge by description Definition: We shall say that an object is known by description when we know that it is the so-and-so, This is one reason why Russell cares so much about analysing the word the. Paradigm cases of knowledge by description physical objects other people s minds (other) inferences from theories e.g., mathematical objects most things, in fact

4 patterns in my visual field What I know by acquaintance some simple relations e.g., before universals, i.e. abstract ideas ( whiteness, diversity, brotherhood, and so on [and] all verbs ) memories introspection the self... maybe 1912, pp A basic example the sense-data which make up the appearance of my table are things with which I have acquaintance, things immediately known to me just as they are. My knowledge of the table as a physical object, on the contrary, is not direct knowledge.... My knowledge of the table is of the kind which we shall call knowledge by description. The table is the physical object which causes such-and-such sense-data. But: In order to know anything at all about the table, we must know truths connecting it with things with which we have acquaintance 1912, p. 74 This is serious mum Every proposition which we can understand must be composed wholly of constituents with which we are acquainted. E.g., Julius Caesar was assassinated becomes the man whose name was Julius Caesar was assassinated. In this sentence: Julius Caesar is a noise or shape this means it s marks on a piece of paper or sounds in air. The rest of the sentence consists of concepts which we re acquainted with. We then have to say more about the noise or shape Julius Caesar. 1912, pp We have to get to acquaintance Since we re not acquainted with Julius Caesar, we have to translate the noise or shape into things we re acquanted with. Russell illustrates this for Bismarck. He gets the first Chancellor of the German Empire. Here all the words are abstract except German. And we can be acquainted with abstractions ( universals ), remember. To some [this word] will recall... the look of Germany on the map, which they re acquainted with. Hooray! 1912, p. 86 And finally... why should we believe all this? it is scarcely conceivable that we can make a judgment... without knowing what it is that we are judging... about. We must attach some meaning to the words we use, if we are to speak significantly and not utter mere noise; and the meaning we attach to our words must be something with which we are acquainted. The chief importance of knowledge by description is that it enables us to pass beyond the limits of our private experience. 1912, pp ; also available at This is a refinement of a similar doctrine in Hume.. Russell s logical atomism Logical atomism is the theory that everything can be seen as a system of relations between entities from some privileged class ( particulars ), and that all or many factual statements can be analysed by means of definitions and logic into statements of atomic facts. Russell s logical atomism was based on his own Phenomenalism, Frege s logic, Leibniz s atomism, and possibly also Meinong s earlier logical atomism. Russell s theory brought out the possibility of moving from the logical structure of mathematics to the logical structure of all language to the logical structure of the world. This became Wittgenstein s program in his Tractatus Logico-Philosophicus (1921).

5 The relationship with Idealism The philosophy which I advocate is generally regarded as a species of realism, and accused of inconsistency because of the elements in it which seem contrary to that doctrine. For my part, I do not regard the issue between realists and their opponents as a fundamental one Bertrand Russell, Logical Atomism, La Salle: Open Court, 1924/1985, p. 157 I doubt that this was really true of Russell. But it was true of Carnap, as we ll see later. And it s a popular view now (Simon Blackburn). Russell s logical atomism Atomic entities can be subjective (first-person), but facts are objective. Facts are expressed by propositions, which are sentences. But propositions are not proper names for facts, because there are false propositions but no false facts. Why not? Because facts are objective. What are the atoms? White is a simple symbol, and whiteness is a simple property, because it can be the object of acquaintance. This applies to phenomenal whiteness, not a set of wavelengths. I do not want you to think about the piece of chalk I am holding, but of what you see when you look at the chalk. If one says, This is white it will do for about as simple a fact as you can get hold of. Bertrand Russell, The Philosophy of Logical Atomism, La Salle: Open Court, 1918/1985, p.59 Talking about atoms 1 How are you to express in words an atomic proposition? An atomic proposition is one which does mention actual particulars, not merely describe them but actually name them... Yet it does seem a little odd if, having made a dot on the blackboard, I call it John. Bertrand Russell, The Philosophy of Logical Atomism, La Salle: Open Court, 1918/1985, p.61 The only kind of word that is theoretically capable of standing for a particular is a proper name, and the whole matter of proper names is rather curious.... you cannot ever talk about a particular particular [sic] except by means of a proper name.... Talking about atoms 2 The names that we commonly use, like Socrates, are really abbreviations for descriptions; not only that, but what they describe are not particulars but complicated systems of classes or series.... The only words one does use as names in the logical sense are words like this or that.... If you agree that This is white, meaning the this that you see, you are using this as a proper name. : ) But if you try to apprehend the proposition that I am expressing when I say This is white, you cannot do it. : ( Bertrand Russell, The Philosophy of Logical Atomism, La Salle: Open Court, 1918/1985, p.62 Logic in logical atomism Atomic propositions can be combined into molecular propositions using logical words such as and & if... then, which are truth functional i.e., they can be completely understood using truth tables. Important: Molecular propositions correspond to molecular facts, but they do not indicate any additional complexity in the world. I.e., the world can be completely described by atomic facts. Note the similarities to Idealism.

6 More logic in logical atomism Atomic propositions can also be combined in molecular propositions about beliefs and desires: I believe I am a hat, I wish I was an alpaca, etc. These are NOT relations between a person and a fact. Why not? Because facts are objective, but beliefs can be wrong. Worst case scenario: beliefs can be about nonexistent objects. There cannot be any facts about nonexistent objects. (?) This was a major motivating argument for Russell. They can be analysed into atomic propositions, but these analyses are not truth functional they are more like maps. Bertrand Russell, The Philosophy of Logical Atomism, La Salle: Open Court, 1918/1985, p.90 There s an infinite number of other possible forms of propositions and facts.