28 ideas
20109 | Hegel inserted society and history between the God-world, man-nature, man-being binary pairs [Hegel, by Safranski] |
Full Idea: Before Hegel, people thought in binary oppositions of God and the world, man and nature, man and being. After Hegel an intervening world of society and history was inserted between these pairs. | |
From: report of Georg W.F.Hegel (Introduction to the Philosophy of History [1840]) by Rüdiger Safranski - Nietzsche: a philosophical biography 05 | |
A reaction: This is what Popper later called 'World Three'. This might be seen as the start of what we islanders call 'continental' philosophy, which we have largely ignored. Analytic philosophy only discovered this through philosophy of language. |
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. |
17610 | The Axiom of Choice paradoxically allows decomposing a sphere into two identical spheres [Maddy] |
Full Idea: One feature of the Axiom of Choice that troubled many mathematicians was the so-called Banach-Tarski paradox: using the Axiom, a sphere can be decomposed into finitely many parts and those parts reassembled into two spheres the same size as the original. | |
From: Penelope Maddy (Defending the Axioms [2011], 1.3) | |
A reaction: (The key is that the parts are non-measurable). To an outsider it is puzzling that the Axiom has been universally accepted, even though it produces such a result. Someone can explain that, I'm sure. |
17620 | Critics of if-thenism say that not all starting points, even consistent ones, are worth studying [Maddy] |
Full Idea: If-thenism denies that mathematics is in the business of discovering truths about abstracta. ...[their opponents] obviously don't regard any starting point, even a consistent one, as equally worthy of investigation. | |
From: Penelope Maddy (Defending the Axioms [2011], 3.3) | |
A reaction: I have some sympathy with if-thenism, in that you can obviously study the implications of any 'if' you like, but deep down I agree with the critics. |
17605 | Hilbert's geometry and Dedekind's real numbers were role models for axiomatization [Maddy] |
Full Idea: At the end of the nineteenth century there was a renewed emphasis on rigor, the central tool of which was axiomatization, along the lines of Hilbert's axioms for geometry and Dedekind's axioms for real numbers. | |
From: Penelope Maddy (Defending the Axioms [2011], 1.3) |
17625 | If two mathematical themes coincide, that suggest a single deep truth [Maddy] |
Full Idea: The fact that two apparently fruitful mathematical themes turn out to coincide makes it all the more likely that they're tracking a genuine strain of mathematical depth. | |
From: Penelope Maddy (Defending the Axioms [2011], 5.3ii) |
17615 | Every infinite set of reals is either countable or of the same size as the full set of reals [Maddy] |
Full Idea: One form of the Continuum Hypothesis is the claim that every infinite set of reals is either countable or of the same size as the full set of reals. | |
From: Penelope Maddy (Defending the Axioms [2011], 2.4 n40) |
17618 | Set-theory tracks the contours of mathematical depth and fruitfulness [Maddy] |
Full Idea: Our set-theoretic methods track the underlying contours of mathematical depth. ...What sets are, most fundamentally, is markers for these contours ...they are maximally effective trackers of certain trains of mathematical fruitfulness. | |
From: Penelope Maddy (Defending the Axioms [2011], 3.4) | |
A reaction: This seems to make it more like a map of mathematics than the actual essence of mathematics. |
17614 | The connection of arithmetic to perception has been idealised away in modern infinitary mathematics [Maddy] |
Full Idea: Ordinary perceptual cognition is most likely involved in our grasp of elementary arithmetic, but ...this connection to the physical world has long since been idealized away in the infinitary structures of contemporary pure mathematics. | |
From: Penelope Maddy (Defending the Axioms [2011], 2.3) | |
A reaction: Despite this, Maddy's quest is for a 'naturalistic' account of mathematics. She ends up defending 'objectivity' (and invoking Tyler Burge), rather than even modest realism. You can't 'idealise away' the counting of objects. I blame Cantor. |
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'? |
23274 | World history has no room for happiness [Hegel] |
Full Idea: World history is not the place for happiness. Periods of happiness are empty pages in history. | |
From: Georg W.F.Hegel (Introduction to the Philosophy of History [1840], 3) | |
A reaction: Clearly, Hegel thinks the progress of world history is much more important than happiness. This idea gives backing to those who don't care much about the casualties on either side in a major war. |
23275 | The state of nature is one of untamed brutality [Hegel] |
Full Idea: The 'state of nature' is not an ideal condition, but a condition of injustice, of violence, of untamed natural drives, inhuman acts and emotions. | |
From: Georg W.F.Hegel (Introduction to the Philosophy of History [1840], 3) | |
A reaction: He agrees with Hobbes, and disagrees with Rousseau. Hobbes's solution is authoritarian monarchy, but Hegel's solution is the unified and focused state, in which freedom can be realised. |
23276 | The soul of the people is an organisation of its members which produces an essential unity [Hegel] |
Full Idea: The soul [of the people] exists only insofar as it is an organisation of its members, which - by taking itself together in its simple unity - produce the soul. Thus the people is one individuality in its essence. | |
From: Georg W.F.Hegel (Introduction to the Philosophy of History [1840], 3) | |
A reaction: Hegel is seen (e.g. by Charles Taylor) as the ancestor of a rather attractive communitarianism, but I think Popper is more accurate in seeing him as the first stage of modern totalitarianism. The people seen as one individual terrifies me. |
23272 | The human race matters, and individuals have little importance [Hegel] |
Full Idea: Individuals are of slight importance compared to the mass of the human race. | |
From: Georg W.F.Hegel (Introduction to the Philosophy of History [1840], 3) | |
A reaction: A perfect statement of the anti-liberal viewpoint. Hegel is complex, but this is the strand that leads to ridiculous totalitarianism, where the highest ideal is to die for the glory of your nation. Importance can only start from individuals. |
23273 | In a good state the goal of the citizens and of the whole state are united [Hegel] |
Full Idea: A state is well constituted and internally strong if the private interest of the citizens is united in the universal goal of the state. | |
From: Georg W.F.Hegel (Introduction to the Philosophy of History [1840], 3) | |
A reaction: The obvious question is who decides on the goals, and what to do with the citizens who don't accept them. |
23271 | The goal of the world is Spirit's consciousness and enactment of freedom [Hegel] |
Full Idea: The final goal of the world is Spirit's consciousness of its freedom, and hence also the actualisation of that very freedom. | |
From: Georg W.F.Hegel (Introduction to the Philosophy of History [1840], 3) | |
A reaction: I have the impression that this ridiculous idea has been very influential in modern French philosophy, since they all seem to be dreaming of some perfect freedom at the end of the rainbow. Freedom is good, but this gives it a bad name. |
23270 | We should all agree that there is reason in history [Hegel] |
Full Idea: We ought to have the firm and unconquerable belief that there is reason in history. | |
From: Georg W.F.Hegel (Introduction to the Philosophy of History [1840], 2) | |
A reaction: This is a ridiculous but hugely influential idea, and I have no idea what makes Hegel believe it. It is the Stoic idea that nature is intrinsically rational, but extending it to human history is absurd. Human exceptionalism. Needs a dose of Darwin. |