21 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. |
13152 | We can talk of 'innumerable number', about the infinite points on a line [Newton] |
Full Idea: If any man shall take the words number and sum in a larger sense, to understand things which are numberless and sumless (such as the infinite points on a line), I could allow him the contradictious phrase 'innumerable number' without absurdity. | |
From: Isaac Newton (Letters to Bentley [1692], 1693.02.25) | |
A reaction: [compressed] I take the key point here to be the phrase of taking number 'in a larger sense'. Like the word 'atom' in physics, the word 'number' retains its traditional reference, but has considerably shifted its scope. Amateurs must live with this. |
13151 | Not all infinites are equal [Newton] |
Full Idea: It is an error that all infinites are equal. | |
From: Isaac Newton (Letters to Bentley [1692], 1693.01.17) | |
A reaction: There follows a discussion of the mathematicians' view of infinity. Cantor was not the first to notice that there is more than one sort of of infinity. |
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) | |
A reaction: In a fairy tale we quantify over fairies, so some further criterion will obviously be needed. |
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. |
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. |
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. |
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'? |
13304 | Learned men gain more in one day than others do in a lifetime [Posidonius] |
Full Idea: In a single day there lies open to men of learning more than there ever does to the unenlightened in the longest of lifetimes. | |
From: Posidonius (fragments/reports [c.95 BCE]), quoted by Seneca the Younger - Letters from a Stoic 078 | |
A reaction: These remarks endorsing the infinite superiority of the educated to the uneducated seem to have been popular in late antiquity. It tends to be the religions which discourage great learning, especially in their emphasis on a single book. |
15863 | The principles of my treatise are designed to fit with a belief in God [Newton] |
Full Idea: When I wrote my treatise about our system, I had an eye upon such principles as might work with considering men, for the belief of a deity. | |
From: Isaac Newton (Letters to Bentley [1692], 1692.12.10) | |
A reaction: Harré quotes this, and it shows that the rather passive view of nature Newton developed was to be supplemented by the active power of God. Without God, we need a more active view of nature. |
8340 | I do not pretend to know the cause of gravity [Newton] |
Full Idea: You sometimes speak of gravity as essential and inherent in matter. Pray do no ascribe that notion to me; for the cause of gravity is what I do not pretend to know. | |
From: Isaac Newton (Letters to Bentley [1692], 1693.01.17) | |
A reaction: I take science to be a two-stage operation - first we discern the regularities, and then we explain them. Evolution was spotted, then explained by Darwin. Cancer from cigarettes was spotted, but hasn't been explained. Regularity is the beginning. |
13150 | The motions of the planets could only derive from an intelligent agent [Newton] |
Full Idea: The motions which the planets now have could not spring from any natural cause alone, but were impressed by an intelligent agent. | |
From: Isaac Newton (Letters to Bentley [1692], 1692.12.10) | |
A reaction: He is writing to a cleric, but seems to be quite sincere about this. Elsewhere he just says he doesn't know what causes gravity. |
12178 | That gravity should be innate and essential to matter is absurd [Newton] |
Full Idea: That gravity should be innate, inherent and essential to matter ...is to me so great an absurdity that I believe no man who has in philosophical matters a competent faculty of thinking can ever fall into it. | |
From: Isaac Newton (Letters to Bentley [1692], 1693.02.25) | |
A reaction: He is replying to some sermons, and he pays vague lip service to a possible divine force. Nevertheless, this is thoroughgoing anti-essentialism, and he talks of external 'laws' in the next sentence. Newton still sought the cause of gravity. |
20820 | Time is an interval of motion, or the measure of speed [Posidonius, by Stobaeus] |
Full Idea: Posidonius defined time thus: it is an interval of motion, or the measure of speed and slowness. | |
From: report of Posidonius (fragments/reports [c.95 BCE]) by John Stobaeus - Anthology 1.08.42 | |
A reaction: Hm. Can we define motion or speed without alluding to time? Looks like we have to define them as a conjoined pair, which means we cannot fully understand either of them. |