Combining Texts

All the ideas for 'The Sign of Four', 'The Central Questions of Philosophy' and 'Apriority and Existence'

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21 ideas

2. Reason / E. Argument / 3. Analogy
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.
4. Formal Logic / D. Modal Logic ML / 4. Alethic Modal Logic
The main modal logics disagree over three key formulae [Yablo]
     Full Idea: Lewis's different systems of modal logic differed about such formulae as □P implies □□P; ◊□P implies □P; and ◊S implies □◊S
     From: Stephen Yablo (Apriority and Existence [2000], §06)
     A reaction: Yablo's point is that the various version don't seem to make much difference to our practices in logic, mathematics and science. The problem, says Yablo, is deciding exactly what you mean by 'necessarily' and 'possibly'.
6. Mathematics / A. Nature of Mathematics / 3. Nature of Numbers / a. Numbers
If 'the number of Democrats is on the rise', does that mean that 50 million is on the rise? [Yablo]
     Full Idea: If someone says 'the number of Democrats is on the rise', he or she wants to focus on Democrats, not numbers. If the number is 50 million, is 50 million really on the rise?
     From: Stephen Yablo (Apriority and Existence [2000], §14)
     A reaction: This is a very nice warning from Yablo, against easy platonism, or any sort of platonism at all. We routinely say that numbers are 'increasing', but the real meaning needs entangling. Here it refers to people joining a party.
6. Mathematics / C. Sources of Mathematics / 4. Mathematical Empiricism / b. Indispensability of mathematics
We must treat numbers as existing in order to express ourselves about the arrangement of planets [Yablo]
     Full Idea: It is only by making as if to countenance numbers that one can give expression in English to a fact having nothing to do with numbers, a fact about stars and planets and how they are numerically proportioned.
     From: Stephen Yablo (Apriority and Existence [2000], §13)
     A reaction: To avoid the phrase 'numerically proportioned', he might have alluded to the 'pattern' of the stars and planets. I'm not sure which -ism this is, but it seems to me a good approach. The application is likely to precede the theory.
6. Mathematics / C. Sources of Mathematics / 9. Fictional Mathematics
Platonic objects are really created as existential metaphors [Yablo]
     Full Idea: The means by which platonic objects are simulated is existential metaphor. Numbers are conjured up as metaphorical measures of cardinality.
     From: Stephen Yablo (Apriority and Existence [2000], §12)
     A reaction: 'Fictional' might be a better word than 'metaphorical', since the latter usually implies some sort of comparison.
7. Existence / D. Theories of Reality / 7. Fictionalism
We quantify over events, worlds, etc. in order to make logical possibilities clearer [Yablo]
     Full Idea: It is not that the contents of sentences are inexpressible without quantifying over events, worlds, etc. (they aren't). But the logical relations become much more tractable if we represent them quantificationally.
     From: Stephen Yablo (Apriority and Existence [2000], §13)
     A reaction: Yablo is explaining why we find ourselves committed to abstract objects. It is essentially, as I am beginning to suspect, a conspiracy of logicians. What on earth is 'the empty set' when it is at home? What's it made of?
7. Existence / D. Theories of Reality / 11. Ontological Commitment / b. Commitment of quantifiers
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)
8. Modes of Existence / E. Nominalism / 1. Nominalism / c. Nominalism about abstracta
Philosophers keep finding unexpected objects, like models, worlds, functions, numbers, events, sets, properties [Yablo]
     Full Idea: There's a tradition in philosophy of finding 'unexpected objects' in truth-conditions, such as countermodels, possible worlds, functions, numbers, events, sets and properties.
     From: Stephen Yablo (Apriority and Existence [2000], §02)
     A reaction: This is a very nice perspective on the whole matter of abstract objects. If we find ourselves reluctantly committed to the existence of something which is ontologically peculiar, we should go back to the philosophical drawing-board.
9. Objects / D. Essence of Objects / 3. Individual Essences
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.
14. Science / C. Induction / 1. Induction
If you eliminate the impossible, the truth will remain, even if it is weird [Conan Doyle]
     Full Idea: When you have eliminated the impossible, whatever remains, however improbable, must be the truth.
     From: Arthur Conan Doyle (The Sign of Four [1890], Ch. 6)
     A reaction: A beautiful statement, by Sherlock Holmes, of Eliminative Induction. It is obviously not true, of course. Many options may still face you after you have eliminated what is actually impossible.
15. Nature of Minds / A. Nature of Mind / 4. Other Minds / c. Knowing other minds
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.
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'.
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.
16. Persons / B. Nature of the Self / 5. Self as Associations
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.
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.
16. Persons / B. Nature of the Self / 7. Self and Body / a. Self needs body
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.
16. Persons / C. Self-Awareness / 2. Knowing the Self
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?
16. Persons / D. Continuity of the Self / 2. Mental Continuity / c. Inadequacy of mental continuity
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.
17. Mind and Body / E. Mind as Physical / 1. Physical Mind
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'.
19. Language / D. Propositions / 6. Propositions Critique
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'?
19. Language / F. Communication / 6. Interpreting Language / d. Metaphor
Hardly a word in the language is devoid of metaphorical potential [Yablo]
     Full Idea: There is hardly a word in the language - be it an adverb, preposition, conjunction, or what have you - that is devoid of metaphorical potential.
     From: Stephen Yablo (Apriority and Existence [2000], §12)
     A reaction: Yablo goes on to claim that metaphor is at the heart of all of our abstract thinking. 'Dead metaphors' (like the "mouth" of a river) sink totally into literal language. I think Yablo is on the right lines.