20 ideas
| 23367 | Even pointing a finger should only be done for a reason [Epictetus] |
| Full Idea: Philosophy says it is not right even to stretch out a finger without some reason. | |
| From: Epictetus (fragments/reports [c.57], 15) | |
| A reaction: The key point here is that philosophy concerns action, an idea on which Epictetus is very keen. He rather despise theory. This idea perfectly sums up the concept of the wholly rational life (which no rational person would actually want to live!). |
| 3993 | Arguments are nearly always open to challenge, but they help to explain a position rather than force people to believe [Lewis] |
| Full Idea: Philosophical arguments are never incontrovertible - well, hardly ever. Their purpose is to help expound a position, not to coerce agreement. | |
| From: David Lewis (Lewis: reduction of mind (on himself) [1994], p.419) | |
| A reaction: A bit over-cautious, perhaps. Most philosophers are converted to a position when they hear a single key argument, though it is probably 'tipping the balance' of previous discussions. |
| 3990 | The whole truth supervenes on the physical truth [Lewis] |
| Full Idea: The whole truth supervenes on the physical truth. | |
| From: David Lewis (Lewis: reduction of mind (on himself) [1994], p.412) | |
| A reaction: This seems to me the central truth about brains, and we should not be lured into abandoning it. We should not, however, exclude the possibility that there is a non-physical reality. |
| 3991 | Where pixels make up a picture, supervenience is reduction [Lewis] |
| Full Idea: In the case of millions of pixels making up a picture on a computer screen, the supervenience is reduction. | |
| From: David Lewis (Lewis: reduction of mind (on himself) [1994], p.414) | |
| A reaction: Since 'supervenience' seems a suspect relationship about which no one is clear, this is a point very much worth making. |
| 5163 | Basic propositions refer to a single experience, are incorrigible, and conclusively verifiable [Ayer] |
| Full Idea: There is a class of empirical propositions, which I call 'basic propositions', which can be verified conclusively, since they refer solely to the contents of a single experience, which are incorrigible. | |
| From: A.J. Ayer (Introduction to 'Language Truth and Logic' [1946], p.13) | |
| A reaction: A classic statement of empirical foundationalism. I sort of agree that 'single experiences' are a 'given' for philosophy, but is questionable whether there is anything which could both be a single experience AND give rise to a proposition. |
| 3995 | A mind is an organ of representation [Lewis] |
| Full Idea: A mind is an organ of representation. | |
| From: David Lewis (Lewis: reduction of mind (on himself) [1994], p.421) | |
| A reaction: This does not seem to necessarily involve awareness, so it seems to put intentionality at the centre of things. It is a good slogan. |
| 5167 | The argument from analogy fails, so the best account of other minds is behaviouristic [Ayer] |
| Full Idea: There are too many objections to the argument from analogy, so I am inclined to revert to a 'behaviouristic' interpretation of propositions about other people's experiences. | |
| From: A.J. Ayer (Introduction to 'Language Truth and Logic' [1946], p.26) | |
| A reaction: It seems odd to vote for behaviourism on one issue, if you aren't a general subscriber. It is one thing to say that behaviour is the best evidence for your explanation, quite another to equate the other mind with its behaviour. |
| 3994 | Human pain might be one thing; Martian pain might be something else [Lewis] |
| Full Idea: Human pain might be one thing. Martian pain might be something else. | |
| From: David Lewis (Lewis: reduction of mind (on himself) [1994], p.420) | |
| A reaction: A key suggestion in support of type-type physicalism, and against the multiple realisability objection to the identity theory |
| 3989 | I am a reductionist about mind because I am an a priori reductionist about everything [Lewis] |
| Full Idea: My reductionism about mind began as part of an a priori reductionism about everything. | |
| From: David Lewis (Lewis: reduction of mind (on himself) [1994], p.412) | |
| A reaction: He says this is 'a priori' to avoid giving hostages to fortune, but I think is the best explanation of the total evidence facing us |
| 3992 | Folk psychology makes good predictions, by associating mental states with causal roles [Lewis] |
| Full Idea: Folk psychology is a powerful instrument of prediction, …which associates with each mental state a typical causal role. | |
| From: David Lewis (Lewis: reduction of mind (on himself) [1994], p.416) | |
| A reaction: This seems a good account of why we should take folk psychology very seriously, even if it is sometimes wrong (e.g. about people who are mentally ill). |
| 3996 | Folk psychology doesn't say that there is a language of thought [Lewis] |
| Full Idea: I don't believe that folk psychology says there is a language of thought. | |
| From: David Lewis (Lewis: reduction of mind (on himself) [1994], p.422) | |
| A reaction: This is aimed at Jerry Fodor. Certainly folk psychology is a strong theory, but a so-called 'language of thought' (the brain's machine code) seems a much weaker one. |
| 3998 | If you don't share an external world with a brain-in-a-vat, then externalism says you don't share any beliefs [Lewis] |
| Full Idea: If the famous brain in a bottle is your exact duplicate in brain states, but only experiences the computer's virtual reality, so that you share no objects of acquaintance, then according to externalists you share no beliefs whatsoever. | |
| From: David Lewis (Lewis: reduction of mind (on himself) [1994], p.424) | |
| A reaction: A very nice reductio ad absurdum of the idea that all concepts and beliefs have external meaning. |
| 3997 | Nothing shows that all content is 'wide', or that wide content has logical priority [Lewis] |
| Full Idea: There is nothing to support the thesis that wide content is the only kind of content, or that it is any way pre-eminent or basic. | |
| From: David Lewis (Lewis: reduction of mind (on himself) [1994], p.424) | |
| A reaction: The idea that all content is 'wide' seems quite wrong. We can't all be wrong about the meaning of a word, because the underlying facts have not yet been discovered. |
| 3999 | A spontaneous duplicate of you would have your brain states but no experience, so externalism would deny him any beliefs [Lewis] |
| Full Idea: According to externalists, Davidson's 'swampman' is your exact duplicate in brains states, but hasn't had time to become acquainted with much, so he has virtually no beliefs. | |
| From: David Lewis (Lewis: reduction of mind (on himself) [1994], p.425) | |
| A reaction: An implausible fantasy, but it does highlight the fact that beliefs and concepts are primarily internal states. |
| 4000 | Wide content derives from narrow content and relationships with external things [Lewis] |
| Full Idea: Wide content is derivative, a product of narrow content and relationships of acquaintance with external things. | |
| From: David Lewis (Lewis: reduction of mind (on himself) [1994], p.430) | |
| A reaction: I would say: content is a mental state, but it is created and fixed by a community, and wide content is the part fixed by experts in the community. We can all be wrong about meanings, and occasionally most of us are wrong about a specialised meaning. |
| 5164 | A statement is meaningful if observation statements can be deduced from it [Ayer] |
| Full Idea: In the improved version, a statement was verifiable, and consequently meaningful, if 'some observation-statement can be deduced from it in conjunction with certain other premises, without being deducible from those other premises alone'. | |
| From: A.J. Ayer (Introduction to 'Language Truth and Logic' [1946], p.15) | |
| A reaction: I.Berlin showed that any statement S could pass this test, because if you assert 'S' and 'If S then O', these two statements entail O, which could be some random observation. Hence a 1946 revised version had to be produced. |
| 5165 | Directly verifiable statements must entail at least one new observation statement [Ayer] |
| Full Idea: A statement is directly verifiable if it is either itself an observation-statement,or is such that in conjunction with one or more observation-statements it entails at least one observation-statement which is not deducible from these other premises alone. | |
| From: A.J. Ayer (Introduction to 'Language Truth and Logic' [1946], p.17) | |
| A reaction: This is the 1946 revised version of the Verification Principle, which was then torpedoed by an elaborate counterexample from Alonzo Church. Ayer thereafter abandoned attempts to find a precise statement of it. |
| 5166 | The principle of verification is not an empirical hypothesis, but a definition [Ayer] |
| Full Idea: I wish the principle of verification to be regarded, not as an empirical hypothesis, but as a definition. | |
| From: A.J. Ayer (Introduction to 'Language Truth and Logic' [1946], p.21) | |
| A reaction: This is Ayer's attempt to meet the well known objection of 'turning the tables' on his theory (by asking whether it is tautological or empirically verifiable). However, if it is just a definition, then presumably it is completely arbitrary… |
| 5162 | Sentences only express propositions if they are meaningful; otherwise they are 'statements' [Ayer] |
| Full Idea: I suggest that every grammatically significant indicative sentence expresses a 'statement', but the word 'proposition' will be reserved for what is expressed by sentences that are literally meaningful. | |
| From: A.J. Ayer (Introduction to 'Language Truth and Logic' [1946], p.10) | |
| A reaction: We don't have to accept Ayer's over-fussy requirements for what is meaningful to accept that this is a good distinction. Every day we hear statements from people (e.g. politicians) in which we can fish in vain for the underlying proposition. |
| 5168 | Moral approval and disapproval concerns classes of actions, rather than particular actions [Ayer] |
| Full Idea: The common objects of moral approval and disapproval are not particular actions so much as classes of actions. | |
| From: A.J. Ayer (Introduction to 'Language Truth and Logic' [1946], p.27) | |
| A reaction: This 1946 revision of his pure emotivism looks like a move towards Hare's prescriptivism, where classes, rules and principles are seen as the window-dressing of emotivism. It's still a bad theory. |