18 ideas
| 12456 | I aim to establish certainty for mathematical methods [Hilbert] |
| Full Idea: The goal of my theory is to establish once and for all the certitude of mathematical methods. | |
| From: David Hilbert (On the Infinite [1925], p.184) | |
| A reaction: This is the clearest statement of the famous Hilbert Programme, which is said to have been brought to an abrupt end by Gödel's Incompleteness Theorems. |
| 12461 | We believe all mathematical problems are solvable [Hilbert] |
| Full Idea: The thesis that every mathematical problem is solvable - we are all convinced that it really is so. | |
| From: David Hilbert (On the Infinite [1925], p.200) | |
| A reaction: This will include, for example, Goldbach's Conjecture (every even is the sum of two primes), which is utterly simple but with no proof anywhere in sight. |
| 9633 | No one shall drive us out of the paradise the Cantor has created for us [Hilbert] |
| Full Idea: No one shall drive us out of the paradise the Cantor has created for us. | |
| From: David Hilbert (On the Infinite [1925], p.191), quoted by James Robert Brown - Philosophy of Mathematics | |
| A reaction: This is Hilbert's famous refusal to accept any account of mathematics, such as Kant's, which excludes actual infinities. Cantor had laid out a whole glorious hierarchy of different infinities. |
| 12460 | We extend finite statements with ideal ones, in order to preserve our logic [Hilbert] |
| Full Idea: To preserve the simple formal rules of ordinary Aristotelian logic, we must supplement the finitary statements with ideal statements. | |
| From: David Hilbert (On the Infinite [1925], p.195) | |
| A reaction: I find very appealing the picture of mathematics as rooted in the physical world, and then gradually extended by a series of 'idealisations', which should perhaps be thought of as fictions. |
| 12462 | Only the finite can bring certainty to the infinite [Hilbert] |
| Full Idea: Operating with the infinite can be made certain only by the finitary. | |
| From: David Hilbert (On the Infinite [1925], p.201) | |
| A reaction: See 'Compactness' for one aspect of this claim. I think Hilbert was fighting a rearguard action, and his idea now has few followers. |
| 12455 | The idea of an infinite totality is an illusion [Hilbert] |
| Full Idea: Just as in the limit processes of the infinitesimal calculus, the infinitely large and small proved to be a mere figure of speech, so too we must realise that the infinite in the sense of an infinite totality, used in deductive methods, is an illusion. | |
| From: David Hilbert (On the Infinite [1925], p.184) | |
| A reaction: This is a very authoritative rearguard action. I no longer think the dispute matters much, it being just a dispute over a proposed new meaning for the word 'number'. |
| 12457 | There is no continuum in reality to realise the infinitely small [Hilbert] |
| Full Idea: A homogeneous continuum which admits of the sort of divisibility needed to realise the infinitely small is nowhere to be found in reality. | |
| From: David Hilbert (On the Infinite [1925], p.186) | |
| A reaction: He makes this remark as a response to Planck's new quantum theory (the year before the big works of Heisenberg and Schrödinger). Personally I don't see why infinities should depend on the physical world, since they are imaginary. |
| 12459 | The subject matter of mathematics is immediate and clear concrete symbols [Hilbert] |
| Full Idea: The subject matter of mathematics is the concrete symbols themselves whose structure is immediately clear and recognisable. | |
| From: David Hilbert (On the Infinite [1925], p.192) | |
| A reaction: I don't think many people will agree with Hilbert here. Does he mean token-symbols or type-symbols? You can do maths in your head, or with different symbols. If type-symbols, you have to explain what a type is. |
| 18112 | Mathematics divides in two: meaningful finitary statements, and empty idealised statements [Hilbert] |
| Full Idea: We can conceive mathematics to be a stock of two kinds of formulas: first, those to which the meaningful communications of finitary statements correspond; and secondly, other formulas which signify nothing and which are ideal structures of our theory. | |
| From: David Hilbert (On the Infinite [1925], p.196), quoted by David Bostock - Philosophy of Mathematics 6.1 |
| 9636 | My theory aims at the certitude of mathematical methods [Hilbert] |
| Full Idea: The goal of my theory is to establish once and for all the certitude of mathematical methods. | |
| From: David Hilbert (On the Infinite [1925], p.184), quoted by James Robert Brown - Philosophy of Mathematics Ch.5 | |
| A reaction: This dream is famous for being shattered by Gödel's Incompleteness Theorem a mere six years later. Neverless there seem to be more limited certainties which are accepted in mathematics. The certainty of the whole of arithmetic is beyond us. |
| 21103 | Moral questions can only be decided by common opinion [Hume] |
| Full Idea: Though an appeal to general opinion may justly, in the speculative sciences of metaphysics, natural philosophy or astronomy, be deemed unfair, yet in all questions with regard to morals there is really no other standard for deciding controversies. | |
| From: David Hume (Of the original contract [1741], p.291) | |
| A reaction: Surely this is too pessimistic. Common opinion decided to burn people to death for being witches. Common opinion may usually win, but there must sometimes be good grounds for resisting it. |
| 468 | Musical performance can reveal a range of virtues [Damon of Ath.] |
| Full Idea: In singing and playing the lyre, a boy will be likely to reveal not only courage and moderation, but also justice. | |
| From: Damon (fragments/reports [c.460 BCE], B4), quoted by (who?) - where? |
| 21099 | People must have agreed to authority, because they are naturally equal, prior to education [Hume] |
| Full Idea: When we consider how nearly equal all men are in their bodily force, and even in their mental powers and faculties, till cultivated by education, ...then nothing but their own consent could at first associate them together, and subject them to authority. | |
| From: David Hume (Of the original contract [1741], p.276) | |
| A reaction: This doesn't sound very convincing. Some people are much better suited than others to training and education. Men vary enormously in size. |
| 21100 | The idea that society rests on consent or promises undermines obedience [Hume] |
| Full Idea: Were you to preach in most parts of the world that political connections are founded altogether on voluntary consent or a mutual promise, the magistrate would soon imprison you as seditious for loosening the ties of obedience. | |
| From: David Hume (Of the original contract [1741], p.278) | |
| A reaction: He cites obedience as the prime civic virtue, because the law can't operate without it. He doesn't seem to consider the limiting cases of obedience, which makes him essentially a conservative. |
| 20495 | We no more give 'tacit assent' to the state than a passenger carried on board a ship while asleep [Hume] |
| Full Idea: [If we give 'tacit' assent to the state] ...we may as well assert that a man, by remaining in a vessel, freely consents to the dominion of the master, though he was carried aboard while asleep. | |
| From: David Hume (Of the original contract [1741], p.283) | |
| A reaction: We should probably drop the whole idea that we give assent to the state. We are stuck with a state, and a few of us can escape, if it seems important enough, but most of us have no choice. He hope to assent to the controllers of the state. |
| 21101 | The people would be amazed to learn that government arises from their consent [Hume] |
| Full Idea: When we assert that all lawful government arises from the consent of the people, we certainly do them a great deal more honour than they deserve, or even expect or desire from us. | |
| From: David Hume (Of the original contract [1741], p.285) | |
| A reaction: Hume has no interest in the purely abstract idea of a contract, and scorns Locke's idea of tacit consent to government. I assume he would dismiss Rawls as unrealistic theorising. Hume loves peace, and is alarmed by change. |
| 6703 | Poor people lack the knowledge or wealth to move to a different state [Hume] |
| Full Idea: Can we seriously say, that a poor peasant or artisan has a free choice to leave his country, when he knows no foreign language or manners, and lives, from day to day, by the small wages that he acquires? | |
| From: David Hume (Of the original contract [1741], p.283) | |
| A reaction: Of course, in the nineteenth century the Scottish poor did, going to America, which welcomed the poor, and spoke English. Hume's point is the right reply to anyone who says 'If you don't like it, go elsewhere'. Also 'No! Change it!' |
| 21102 | We all know that the history of property is founded on injustices [Hume] |
| Full Idea: Reason tells us that there is no property in durable objects, such as land or houses, when carefully examined in passing from hand to hand, but must, in some period, have been founded on fraud and injustice. | |
| From: David Hume (Of the original contract [1741], p.288) | |
| A reaction: A prime objection to Nozick, who fantasises about an initial position of just ownership, which can then be the subject of just contracts. In 1866 thousands of white people were granted land in the USA, but not a single black freed slave got anything. |