44 ideas
18730 | The history of philosophy only matters if the subject is a choice between rival theories [Wittgenstein] |
Full Idea: If philosophy were a matter of choice between rival theories, then it would be sound to teach it historically. But if it is not, then it is a fault to teach it historically, because it is quite unnecessary; we can tackle the subject direct. | |
From: Ludwig Wittgenstein (Lectures 1930-32 (student notes) [1931], C V A) | |
A reaction: Wittgenstein was a bit notorious for not knowing the history of the subject terribly well, and this explains why. Presumably our tackling the subject direct will not have the dreadful consequence of producing yet another theory. |
18704 | Philosophy tries to be rid of certain intellectual puzzles, irrelevant to daily life [Wittgenstein] |
Full Idea: Philosophy is the attempt to be rid of a particular kind of puzzlement. This 'philosophical' puzzlement is one of the intellect and not of instinct. Philosophical puzzles are irrelevant to our every-day life. | |
From: Ludwig Wittgenstein (Lectures 1930-32 (student notes) [1931], A I.1) | |
A reaction: All enquiry begins with puzzles, and they are cured by explanations, which result in understanding. In that sense he is right. I entirely disagree that the puzzles are irrelevant to daily life. |
18710 | Philosophers express puzzlement, but don't clearly state the puzzle [Wittgenstein] |
Full Idea: Philosophers as 'Why?' and 'What?' without knowing clearly what their questions are. They are expressing a feeling of mental uneasiness. | |
From: Ludwig Wittgenstein (Lectures 1930-32 (student notes) [1931], B I.1) | |
A reaction: He suggests it is childish to express puzzlement, instead of asking for precise information. How odd. All enquiries start with vague puzzlement, which gradually comes into focus, or else is abandoned. |
18732 | We don't need a theory of truth, because we use the word perfectly well [Wittgenstein] |
Full Idea: It is nonsense to try to find a theory of truth, because we can see that in everyday life we use the word quite clearly and definitely in various different senses. | |
From: Ludwig Wittgenstein (Lectures 1930-32 (student notes) [1931], C V B) | |
A reaction: This was a year before Tarski published his famous theory of truth for formal languages. Prior to that, most philosophers were giving up on truth. Would he say the same about 'gravity' or 'inflation'? |
18714 | We already know what we want to know, and analysis gives us no new facts [Wittgenstein] |
Full Idea: In philosophy we know already all that we want to know; philosophical analysis does not give us any new facts. | |
From: Ludwig Wittgenstein (Lectures 1930-32 (student notes) [1931], B V.1) |
18706 | Words of the same kind can be substituted in a proposition without producing nonsense [Wittgenstein] |
Full Idea: 'Blue' and 'brown' are of the same kind, for the substitution of one for the other, though it may falsify the proposition, does not make nonsense of it. | |
From: Ludwig Wittgenstein (Lectures 1930-32 (student notes) [1931], A I.4) | |
A reaction: He chooses an easy example, because they are determinates of the determinable 'coloured'. What if I say 'the sky is blue', and then substitute 'frightening' for 'blue'? |
18735 | Talking nonsense is not following the rules [Wittgenstein] |
Full Idea: Talking nonsense is not following the rules. | |
From: Ludwig Wittgenstein (Lectures 1930-32 (student notes) [1931], C X) | |
A reaction: He doesn't seem to distinguish between syntax and semantics, and makes it sound as if all nonsense is syntactic, which it isn't. |
18719 | Grammar says that saying 'sound is red' is not false, but nonsense [Wittgenstein] |
Full Idea: If grammar says that you cannot say that a sound is red, it means not that it is false to say so but that it is nonsense - i.e. not a language at all. | |
From: Ludwig Wittgenstein (Lectures 1930-32 (student notes) [1931], B IX.6) | |
A reaction: I am baffled as to why he thinks 'grammar' is what prohibits such a statement. Surely the world, the nature of sound and colour, is what makes the application of the predicate wrong. Sounds aren't coloured, so they can't be red. False, not nonsense. |
18731 | There is no theory of truth, because it isn't a concept [Wittgenstein] |
Full Idea: It is wrong to say that there is any one theory of truth, for truth is not a concept. | |
From: Ludwig Wittgenstein (Lectures 1930-32 (student notes) [1931], C V B) | |
A reaction: This makes you wonder how he understood the word 'concept'. In most modern discussions truth seems to be a concept, and in Frege it can be an unsaturated predicate which is satisfied by sentences or thoughts. |
18707 | All thought has the logical form of reality [Wittgenstein] |
Full Idea: Thought must have the logical form of reality if it is to be thought at all. | |
From: Ludwig Wittgenstein (Lectures 1930-32 (student notes) [1931], A V.1) | |
A reaction: This links nicely the idea that true thoughts somehow share the structure of what they refer to, with the idea of logical form in logic. But maybe logical form is a fiction we offer in order to obtain a spurious map of reality. |
18724 | In logic nothing is hidden [Wittgenstein] |
Full Idea: In logic nothing is hidden. | |
From: Ludwig Wittgenstein (Lectures 1930-32 (student notes) [1931], B XII.3) | |
A reaction: If so, then the essence of logic must be there for all to see. The rules of natural deduction are a good shot at showing this. |
18709 | Laws of logic are like laws of chess - if you change them, it's just a different game [Wittgenstein] |
Full Idea: I might as well question the laws of logic as the laws of chess. If I change the rules it is a different game and there is an end of it. | |
From: Ludwig Wittgenstein (Lectures 1930-32 (student notes) [1931], A XI.3) | |
A reaction: No, that isn't the end of it, because there are meta-criteria for preferring one game to another. Why don't we just give up classical logic? It would be such fun to have a wild wacky logic. We can start with 'tonk'. |
18736 | Contradiction is between two rules, not between rule and reality [Wittgenstein] |
Full Idea: Contradiction is between one rule and another, not between rule and reality. | |
From: Ludwig Wittgenstein (Lectures 1930-32 (student notes) [1931], C XIII) | |
A reaction: If I say 'he is sitting' and 'he is standing', it seems to be reality which produces the contradiction. What 'rule' could possibly do it? The rule which says sitting and standing are incompatible? But what makes that so? |
18723 | We may correctly use 'not' without making the rule explicit [Wittgenstein] |
Full Idea: Correct use does not imply the ability to make the rules explicit. Understanding 'not' is like understanding a move in chess. | |
From: Ludwig Wittgenstein (Lectures 1930-32 (student notes) [1931], B XII.1) |
18718 | Saying 'and' has meaning is just saying it works in a sentence [Wittgenstein] |
Full Idea: When we say that the word 'and' has meaning what we mean is that it works in a sentence and is not just a flourish. | |
From: Ludwig Wittgenstein (Lectures 1930-32 (student notes) [1931], B VIII.2) |
18727 | A person's name doesn't mean their body; bodies don't sit down, and their existence can be denied [Wittgenstein] |
Full Idea: The meaning of the words 'Professor Moore' is not a certain human body, because we do not say that the meaning sits on the sofa, and the words occur in the proposition 'Professor Moore does not exist'. | |
From: Ludwig Wittgenstein (Lectures 1930-32 (student notes) [1931], B Easter) | |
A reaction: Brilliant. Love it. Kripke ending up denying the existence of 'meanings'. |
18738 | We don't get 'nearer' to something by adding decimals to 1.1412... (root-2) [Wittgenstein] |
Full Idea: We say we get nearer to root-2 by adding further figures after the decimal point: 1.1412.... This suggests there is something we can get nearer to, but the analogy is a false one. | |
From: Ludwig Wittgenstein (Lectures 1930-32 (student notes) [1931], Notes) |
18708 | Infinity is not a number, so doesn't say how many; it is the property of a law [Wittgenstein] |
Full Idea: 'Infinite' is not an answer to the question 'How many?', since the infinite is not a number. ...Infinity is the property of a law, not of an extension. | |
From: Ludwig Wittgenstein (Lectures 1930-32 (student notes) [1931], A VII.2) |
18737 | There are no positive or negative facts; these are just the forms of propositions [Wittgenstein] |
Full Idea: There are no positive or negative facts. 'Positive' and 'negative' refer to the form of propositions, and not to the facts which verify or falsify them. | |
From: Ludwig Wittgenstein (Lectures 1930-32 (student notes) [1931], C XIII) | |
A reaction: Personally I think if we are going to allow the world to be full of 'facts', then there are negative, conjunctive, disjunctive and hypothetical facts. |
18715 | Using 'green' is a commitment to future usage of 'green' [Wittgenstein] |
Full Idea: If I say this is green, I must say that other things are green too. I am committed to a future usage. | |
From: Ludwig Wittgenstein (Lectures 1930-32 (student notes) [1931], B VI.2) | |
A reaction: This seems to suggest that the eternal verity of a universal concept is just a convention of stability in a language. |
15086 | Absolute necessity might be achievable either logically or metaphysically [Hale] |
Full Idea: Maybe peaceful co-existence between absolute logical necessity and absolute metaphysical necessity can be secured, ..and absolute necessity is their union. ...However, a truth would then qualify as absolutely necessary in two quite different ways. | |
From: Bob Hale (Absolute Necessities [1996], 4) | |
A reaction: Hale is addressing a really big question for metaphysic (absolute necessity) which others avoid. In the end he votes for rejecting 'metaphysical' necessity. I am tempted to vote for rejecting logical necessity (as being relative). 'Absolute' is an ideal. |
8261 | Maybe not-p is logically possible, but p is metaphysically necessary, so the latter is not absolute [Hale] |
Full Idea: It might be metaphysically necessary that p but logically possible that not-p, so that metaphysical necessity is not, after all, absolute. | |
From: Bob Hale (Absolute Necessities [1996]), quoted by E.J. Lowe - The Possibility of Metaphysics 1.5 | |
A reaction: Lowe presents this as dilemma, but it sounds fine to me. Flying pigs etc. have no apparent logical problems, but I can't conceive of a possible world where pigs like ours fly in a world like ours. Earthbound pigs may be metaphysically necessary. |
15081 | A strong necessity entails a weaker one, but not conversely; possibilities go the other way [Hale] |
Full Idea: One type of necessity may be said to be 'stronger' than another when the first always entails the second, but not conversely. This will obtain only if the possibility of the first is weaker than the possibility of the second. | |
From: Bob Hale (Absolute Necessities [1996], 1) | |
A reaction: Thus we would normally say that if something is logically necessary (a very strong claim) then it will have to be naturally necessary. If something is naturally possible, then clearly it will have to be logically possible. Sounds OK. |
15080 | 'Relative' necessity is just a logical consequence of some statements ('strong' if they are all true) [Hale] |
Full Idea: Necessity is 'relative' if a claim of φ-necessary that p just claims that it is a logical consequence of some statements Φ that p. We have a 'strong' version if we add that the statements in Φ are all true, and a 'weak' version if not. | |
From: Bob Hale (Absolute Necessities [1996], 1) | |
A reaction: I'm not sure about 'logical' consequence here. It may be necessary that a thing be a certain way in order to qualify for some category (which would be 'relative'), but that seems like 'sortal' necessity rather than logical. |
15082 | Metaphysical necessity says there is no possibility of falsehood [Hale] |
Full Idea: Friends of metaphysical necessity would want to hold that when it is metaphysically necessary that p, there is no good sense of 'possible' (except, perhaps, an epistemic one) in which it is possible that not-p. | |
From: Bob Hale (Absolute Necessities [1996], 2) | |
A reaction: We might want to say which possible worlds this refers to (and presumably it won't just be in the actual world). The normal claim would refer to all possible worlds. Adding a '...provided that' clause moves it from absolute to relative necessity. |
15085 | 'Broadly' logical necessities are derived (in a structure) entirely from the concepts [Hale] |
Full Idea: 'Broadly' logical necessities are propositions whose truth derives entirely from the concepts involved in them (together, of course, with relevant structure). | |
From: Bob Hale (Absolute Necessities [1996], 3) | |
A reaction: Is the 'logical' part of this necessity bestowed by the concepts, or by the 'structure' (which I take to be a logical structure)? |
15088 | Logical necessities are true in virtue of the nature of all logical concepts [Hale] |
Full Idea: The logical necessities can be taken to be the propositions which are true in virtue of the nature of all logical concepts. | |
From: Bob Hale (Absolute Necessities [1996], p.10) | |
A reaction: This is part of his story of essences giving rise to necessities. His proposal sounds narrow, but logical concepts may have the highest degree of generality which it is possible to have. It must be how the concepts connect that causes the necessities. |
18726 | For each necessity in the world there is an arbitrary rule of language [Wittgenstein] |
Full Idea: To a necessity in the world there corresponds an arbitrary rule in language. | |
From: Ludwig Wittgenstein (Lectures 1930-32 (student notes) [1931], B XIV.2) | |
A reaction: This seems to be hardcore logical positivism, making all necessities arbitrary. Compare Quine on the number of planets. |
15087 | Conceptual necessities are made true by all concepts [Hale] |
Full Idea: Conceptual necessities can be taken to be propositions which are true in virtue of the nature of all concepts. | |
From: Bob Hale (Absolute Necessities [1996], p.9) | |
A reaction: Fine endorse essences for these concepts. Could we then come up with a new concept which contradicted all the others, and destroyed the necessity? Yes, presumably. Presumably witchcraft and astrology are full of 'conceptual necessities'. |
18712 | Understanding is translation, into action or into other symbols [Wittgenstein] |
Full Idea: Understanding is really translation, whether into other symbols or into action. | |
From: Ludwig Wittgenstein (Lectures 1930-32 (student notes) [1931], B I.5) | |
A reaction: The second part of this sounds like pure pragmatism. To do is to understand? I doubt it. Do animals understand anything? |
18280 | We live in sense-data, but talk about physical objects [Wittgenstein] |
Full Idea: The world we live in is the world of sense-data, but the world we talk about is the world of physical objects. | |
From: Ludwig Wittgenstein (Lectures 1930-32 (student notes) [1931], p.82), quoted by J. Alberto Coffa - The Semantic Tradition from Kant to Carnap 13 'Verif' | |
A reaction: I really like that one. Even animals, I surmise, think of objects quite differently from the way they immediately experience them. |
18729 | Part of what we mean by stating the facts is the way we tend to experience them [Wittgenstein] |
Full Idea: There is no need of a theory to reconcile what we know about sense data and what we believe about physical objects, because part of what we mean by saying that a penny is round is that we see it as elliptical in such and such conditions. | |
From: Ludwig Wittgenstein (Lectures 1930-32 (student notes) [1931], C III) | |
A reaction: This is an interesting and cunning move to bridge the gap between our representations and reallity. We may surmise how a thing really is, but then be surprised by the sense-data we get from it. |
18734 | If you remember wrongly, then there must be some other criterion than your remembering [Wittgenstein] |
Full Idea: If you remember wrongly, then there must be some other criterion than your remembering. If you admit another test, then your memory itself is not the test. | |
From: Ludwig Wittgenstein (Lectures 1930-32 (student notes) [1931], C VII) | |
A reaction: If I fear that I am remembering some private solitary event wrongly, there is no other criterion to turn to, so I'm stuck. Sometimes dubious memories are all we have. |
18721 | Explanation and understanding are the same [Wittgenstein] |
Full Idea: For us explanation and understanding are the same, understanding being the correlate of explanation. | |
From: Ludwig Wittgenstein (Lectures 1930-32 (student notes) [1931], B XI.2) | |
A reaction: I'm not convinced that they are 'the same', but they are almost interdependent ideas. Strevens has a nice paper on this. |
18720 | Explanation gives understanding by revealing the full multiplicity of the thing [Wittgenstein] |
Full Idea: An explanation gives understanding, ...but it cannot teach you understanding, it cannot create understanding. It makes further distinctions i.e. it increases multiplicity. When multiplicity is complete, then there is no further misunderstanding. | |
From: Ludwig Wittgenstein (Lectures 1930-32 (student notes) [1931], B X.3) | |
A reaction: The thought seems to resemble Aristotle's idea of definition as gradual division of the subject. To understand is the dismantle the parts and lay them out before us. Wittgenstein was very interested in explanation at this time. |
18716 | A machine strikes us as being a rule of movement [Wittgenstein] |
Full Idea: We are accustomed to look on a machine as the expression of a rule of movement. | |
From: Ludwig Wittgenstein (Lectures 1930-32 (student notes) [1931], B VII.2) | |
A reaction: What a beautiful definition of a machine! I like this because it connects the two halves of my view of the 'essence' of a thing, as derived from Aristotle, as both a causal mechanism and an underlying principle. Cf Turing machines. |
18713 | If an explanation is good, the symbol is used properly in the future [Wittgenstein] |
Full Idea: The criterion of an explanation is whether the symbol explained is used properly in the future. | |
From: Ludwig Wittgenstein (Lectures 1930-32 (student notes) [1931], B II.4) | |
A reaction: This appears to be a pragmatic criterion for the best explanation. It presumably rests on his doctrine that meaning is use, so good explanation is understanding meanings. |
18717 | Thought is an activity which we perform by the expression of it [Wittgenstein] |
Full Idea: Thought is an activity which we perform by the expression of it, and lasts as long as the expression. | |
From: Ludwig Wittgenstein (Lectures 1930-32 (student notes) [1931], B VIII) | |
A reaction: I take this to be an outmoded view of thought, which modern cognitive science has undermined, by showing how little of our thinking is actually conscious. |
18725 | A proposition draws a line around the facts which agree with it [Wittgenstein] |
Full Idea: A proposition gives reality a degree of freedom; it draws a line round the facts which agree with it, and distinguishes them from those which do not. | |
From: Ludwig Wittgenstein (Lectures 1930-32 (student notes) [1931], B XIII.2) | |
A reaction: This seems to be the idea of meaning as the range of truth conditions. Propositions as sets of possible worlds extends this into possible facts which agree with the proposition. Most facts neither agree nor disagree with some proposition. |
18728 | The meaning of a proposition is the mode of its verification [Wittgenstein] |
Full Idea: The meaning of a proposition is the mode of its verification (and two propositions cannot have the same verification). | |
From: Ludwig Wittgenstein (Lectures 1930-32 (student notes) [1931], C I) | |
A reaction: Does this mean that if two sentences have the same mode of verification, then they must be expressing the same proposition? I guess so. |
18705 | Words function only in propositions, like levers in a machine [Wittgenstein] |
Full Idea: Words function only in propositions, like the levers in a machine. | |
From: Ludwig Wittgenstein (Lectures 1930-32 (student notes) [1931], A I.4) | |
A reaction: Hm. Consider the word 'tree'. Did you manage to do it? Was it just a noise? |
18711 | A proposition is any expression which can be significantly negated [Wittgenstein] |
Full Idea: Any affirmation can be negated: if it has sense to say p it also has sense to say ¬p. ...A proposition therefore is any expression which can be significantly negated. | |
From: Ludwig Wittgenstein (Lectures 1930-32 (student notes) [1931], B I.2) | |
A reaction: I'm not sure about 'therefore'. I'm thinking you would have to already grasp the proposition in order to apply his negation test. |
19399 | Prime matter is nothing when it is at rest [Leibniz] |
Full Idea: Primary matter is nothing if considered at rest. | |
From: Gottfried Leibniz (Aristotle and Descartes on Matter [1671], p.90) | |
A reaction: This goes with Leibniz's Idea 13393, that activity is the hallmark of existence. No one seems to have been able to make good sense of prime matter, and it plays little role in Aristotle's writings. |
18733 | Laws of nature are an aspect of the phenomena, and are just our mode of description [Wittgenstein] |
Full Idea: The laws of nature are not outside phenomena. They are part of language and of our way of describing things; you cannot discuss them apart from their physical manifestation. | |
From: Ludwig Wittgenstein (Lectures 1930-32 (student notes) [1931], C V C) | |
A reaction: I suppose this amounts to a Humean regularity theory - that the descriptions pick out patterns in the manifestations. I like the initial claim that they are not external to phenomena. |