19 ideas
| 5331 | You can't infer that because you have a hidden birth-mark, everybody else does [Ayer] |
| Full Idea: My knowing that I had a hidden birth-mark would not entitle me to infer with any great degree of confidence that the same was true of everybody else. | |
| From: A.J. Ayer (The Central Questions of Philosophy [1973], §VI.E) | |
| A reaction: This is the notorious 'induction from a single case' which was used by Mill to prove that other minds exist. It is a very nice illustration of the weakness of arguments from analogy. Probably analogy on its own is useless, but is a key part of induction. |
| 11211 | If a sound conclusion comes from two errors that cancel out, the path of the argument must matter [Rumfitt] |
| Full Idea: If a designated conclusion follows from the premisses, but the argument involves two howlers which cancel each other out, then the moral is that the path an argument takes from premisses to conclusion does matter to its logical evaluation. | |
| From: Ian Rumfitt ("Yes" and "No" [2000], II) | |
| A reaction: The drift of this is that our view of logic should be a little closer to the reasoning of ordinary language, and we should rely a little less on purely formal accounts. |
| 14181 | Validity is where either the situation or the interpretation blocks true premises and false conclusion [Etchemendy, by Read] |
| Full Idea: The Representational account of validity says an argument is valid if there is no situation where the premises are true and the conclusion false. The Interpretation account says the premises are true and conclusion false under no interpretations. | |
| From: report of John Etchemendy (The Concept of Logical Consequence [1999]) by Stephen Read - Formal and Material Consequence 'Inval' | |
| A reaction: My immediate instinct is to want logic to be about situations, rather than interpretations. Situations are more about thought, where interpretations are more about language. I think our account of logic should have some applicability to animals. |
| 14180 | Etchemendy says fix the situation and vary the interpretation, or fix interpretations with varying situations [Etchemendy, by Read] |
| Full Idea: In Etchemendy's Interpretational Semantics (perhaps better called 'Substitutional') we keep the situation fixed and vary the interpretation; in Representational Semantics ('Modal'?) we keep interpretations fixed but consider varying situations. | |
| From: report of John Etchemendy (The Concept of Logical Consequence [1999]) by Stephen Read - Formal and Material Consequence 'Inval' | |
| A reaction: [compressed] These are semantic strategies for interpreting logic, so they are two ways you might go about assessing an argument. |
| 11210 | Standardly 'and' and 'but' are held to have the same sense by having the same truth table [Rumfitt] |
| Full Idea: If 'and' and 'but' really are alike in sense, in what might that likeness consist? Some philosophers of classical logic will reply that they share a sense by virtue of sharing a truth table. | |
| From: Ian Rumfitt ("Yes" and "No" [2000]) | |
| A reaction: This is the standard view which Rumfitt sets out to challenge. |
| 11212 | The sense of a connective comes from primitively obvious rules of inference [Rumfitt] |
| Full Idea: A connective will possess the sense that it has by virtue of its competent users' finding certain rules of inference involving it to be primitively obvious. | |
| From: Ian Rumfitt ("Yes" and "No" [2000], III) | |
| A reaction: Rumfitt cites Peacocke as endorsing this view, which characterises the logical connectives by their rules of usage rather than by their pure semantic value. |
| 2611 | It is currently held that quantifying over something implies belief in its existence [Ayer] |
| Full Idea: It is currently held that we are committed to a belief in the existence of anything over which we quantify. | |
| From: A.J. Ayer (The Central Questions of Philosophy [1973], IX.C) |
| 16520 | We see properties necessary for a kind (in the definition), but not for an individual [Ayer] |
| Full Idea: We can significantly ask what properties it is necessary for something to possess in order to be a thing of such and such a kind, since that asks what properties enter into the definition of the kind. But there is no such definition of the individual. | |
| From: A.J. Ayer (The Central Questions of Philosophy [1973], 9.A.5) | |
| A reaction: [Quoted, not surprisingly, by Wiggins] Illuminating. If essence is just about necessary properties, I begin to see why the sortal might be favoured. I take it to concern explanatory mechanisms, and hence the individual. |
| 2613 | The theory of other minds has no rival [Ayer] |
| Full Idea: The theory that other people besides oneself have mental states is one that has no serious rival. | |
| From: A.J. Ayer (The Central Questions of Philosophy [1973], §VI.E) | |
| A reaction: See 3463, where Searle says there is no such thing as our "theory" about other minds. In a science fiction situation (see 'Blade Runner'), this unrivalled theory could quickly unravel. It could even be a fact that you are the only humanoid with a mind. |
| 5328 | Originally I combined a mentalistic view of introspection with a behaviouristic view of other minds [Ayer] |
| Full Idea: In 1936 I combined a mentalistic analysis of the propositions in which one attributes experiences to oneself with a behaviouristic analysis of the propositions in which one attributes experiences to others. | |
| From: A.J. Ayer (The Central Questions of Philosophy [1973], §VI.D) | |
| A reaction: He then criticises his view for inconsistency. Ryle preferred a behaviouristic account of introspection, but Ayer calls this 'ridiculous'. Ayer hunts for a compromise, but then settles for the right answer, which makes mentalism the 'best explanation'. |
| 5330 | Physicalism undercuts the other mind problem, by equating experience with 'public' brain events [Ayer] |
| Full Idea: The acceptance of physicalism undercuts the other minds problem by equating experiences with events in the brain, which are publicly observable. | |
| From: A.J. Ayer (The Central Questions of Philosophy [1973], §VI.E) | |
| A reaction: It strikes me that if we could actually observe the operations of one another's brains, a great many of the problems of philosophy would never have appeared in the first place. Imagine a transparent skull and brain, with coloured waves moving through it. |
| 5326 | Qualia must be united by a subject, because they lead to concepts and judgements [Ayer] |
| Full Idea: The ground for thinking that qualia are only experiences because they relate to a unifying subject is that they have to be identified, by being brought under concepts, and giving rise to judgements which usually go beyond them. | |
| From: A.J. Ayer (The Central Questions of Philosophy [1973], §VI.B) | |
| A reaction: Thus one of Hume's greatest fans gives the clearest objection to Hume. It strikes me as a very powerful objection, better than anything Carruthers offers (1394,1395,1396). The conceptual element is very hard to disentangle from the qualia. |
| 5325 | Is something an 'experience' because it relates to other experiences, or because it relates to a subject? [Ayer] |
| Full Idea: Is the character of being an item of experience one that can accrue to a quale through its relation to other qualia, or must it consist in a relation to a subject, which is conscious of these elements and distinct from them? | |
| From: A.J. Ayer (The Central Questions of Philosophy [1973], §VI.B) | |
| A reaction: When nicely put like this, it is hard to see how qualia could be experiences just because they relate to one another. It begs the question of what is causing the relationship. There seems to be a Cogito-like assumption of a thinker. |
| 5324 | Bodily identity and memory work together to establish personal identity [Ayer] |
| Full Idea: In general the two criteria of memory and bodily identity work together. | |
| From: A.J. Ayer (The Central Questions of Philosophy [1973], §VI.B) | |
| A reaction: This seems better than any simplistic one-criterion approach. In life we use different criteria for our own identity, as when dreaming, or waking with a hangover, or wondering if we are dead after an accident. |
| 5322 | Self-consciousness is not basic, because experiences are not instrinsically marked with ownership [Ayer] |
| Full Idea: Self-consciousness is not a primitive datum, or in other words the observer's experiences are not intrinsically marked as his own. | |
| From: A.J. Ayer (The Central Questions of Philosophy [1973], §VI.A) | |
| A reaction: This is a very Humean, ruthlessly empiricist view of the matter. Plenty of philosophers (existentialists, or Charles Taylor) would say that our experiences have our interests or values built into them. Why are they experiences, and not just events? |
| 5327 | Temporal gaps in the consciousness of a spirit could not be bridged by memories [Ayer] |
| Full Idea: If there were temporal gaps in the consciousness of disembodied spirits, the occurrences of memory-experiences would not be sufficient to bridge them. | |
| From: A.J. Ayer (The Central Questions of Philosophy [1973], §VI.C) | |
| A reaction: Ayer is very sympathetic to the idea that the body is a key ingredient in personal identity. Without a body, there would be no criteria at all for the continuity of a spirit which lost consciousness for a while, since consciousness is all it is. |
| 5329 | Why shouldn't we say brain depends on mind? Better explanation! [Ayer] |
| Full Idea: If mind and brain exactly correspond we have as good ground for saying the brain depends on the mind as the other way round; if predominance is given to the brain, the reason is that it fits into a wider explanatory system. | |
| From: A.J. Ayer (The Central Questions of Philosophy [1973], §VI.D) | |
| A reaction: A small but significant point. If an 'identity' theory is to be developed, then this step in the argument has to be justified. It is tempting here to move to the eliminativist view, because we no longer have to worry about a 'direction of priority'. |
| 2610 | Talk of propositions is just shorthand for talking about equivalent sentences [Ayer] |
| Full Idea: Our talk of propositions should not be regarded as anything more than a concise way of talking about equivalent sentences. | |
| From: A.J. Ayer (The Central Questions of Philosophy [1973], IX.C) | |
| A reaction: Wrong, though I can see why he says it. We struggle to express difficult propositions by offering several similar (but not equivalent) sentences. What is the criterion for deciding his 'equivalence'? |
| 11214 | We learn 'not' along with affirmation, by learning to either affirm or deny a sentence [Rumfitt] |
| Full Idea: The standard view is that affirming not-A is more complex than affirming the atomic sentence A itself, with the latter determining its sense. But we could learn 'not' directly, by learning at once how to either affirm A or reject A. | |
| From: Ian Rumfitt ("Yes" and "No" [2000], IV) | |
| A reaction: [compressed] This seems fairly anti-Fregean in spirit, because it looks at the psychology of how we learn 'not' as a way of clarifying what we mean by it, rather than just looking at its logical behaviour (and thus giving it a secondary role). |