10 ideas
| 8000 | He who is ignorant of the history of philosophy is doomed to repeat it [Santayana, by MacIntyre] |
| Full Idea: Santayana remarked that he who is ignorant of the history of philosophy is doomed to repeat it. | |
| From: report of George Santayana (The Life of Reason [1906]) by Alasdair MacIntyre - A Short History of Ethics Ch.1 | |
| A reaction: Santayana's remark seems to have been about history in general, so this is a Macintyre thought. It obviously has a lot of truth, and most great philosophers seem hugely knowledgeable. However, ignorance brings a kind of freedom. |
| 10245 | One geometry cannot be more true than another [Poincaré] |
| Full Idea: One geometry cannot be more true than another; it can only be more convenient. | |
| From: Henri Poincaré (Science and Method [1908], p.65), quoted by Stewart Shapiro - Philosophy of Mathematics | |
| A reaction: This is the culminating view after new geometries were developed by tinkering with Euclid's parallels postulate. |
| 15923 | Poincaré rejected the actual infinite, claiming definitions gave apparent infinity to finite objects [Poincaré, by Lavine] |
| Full Idea: Poincaré rejected the actual infinite. He viewed mathematics that is apparently concerned with the actual infinite as actually concerning the finite linguistic definitions the putatively describe actually infinite objects. | |
| From: report of Henri Poincaré (On the Nature of Mathematical Reasoning [1894]) by Shaughan Lavine - Understanding the Infinite |
| 10180 | Mathematicians do not study objects, but relations between objects [Poincaré] |
| Full Idea: Mathematicians do not study objects, but relations between objects; it is a matter of indifference if the objects are replaced by others, provided the relations do not change. They are interested in form alone, not matter. | |
| From: Henri Poincaré (Science and Hypothesis [1902], p.20), quoted by E Reck / M Price - Structures and Structuralism in Phil of Maths §6 | |
| A reaction: This connects modern structuralism with Aritotle's interest in the 'form' of things. Contrary to the views of the likes of Frege, it is hard to see that the number '7' has any properties at all, apart from its relations. A daffodil would do just as well. |
| 9916 | Convention, yes! Arbitrary, no! [Poincaré, by Putnam] |
| Full Idea: Poincaré once exclaimed, 'Convention, yes! Arbitrary, no!'. | |
| From: report of Henri Poincaré (talk [1901]) by Hilary Putnam - Models and Reality | |
| A reaction: An interesting view. It mustn't be assumed that conventions are not rooted in something. Maybe a sort of pragmatism is implied. |
| 18203 | Avoid non-predicative classifications and definitions [Poincaré] |
| Full Idea: Never consider any objects but those capable of being defined in a finite number of word ...Avoid non-predicative classifications and definitions. | |
| From: Henri Poincaré (The Logic of Infinity [1909], p.63), quoted by Penelope Maddy - Naturalism in Mathematics II.4 |
| 18521 | The criterion of existence is the possibility of action [Santayana] |
| Full Idea: The possibility of action ...is the criterion of existence, and the test of substantiality. | |
| From: George Santayana (The Realm of Matter [1930], p.107), quoted by John Heil - The Universe as We Find It | |
| A reaction: I rather like this. I think I would say the power is the criterion of existence. |
| 23060 | The good is not relative, but is rooted in facts about human needs [Santayana] |
| Full Idea: The good is by no means relative to opinion, but is rooted in the unconscious and fatal nature of living beings, a nature which predetermines for them the difference between foods and poisons, happiness and misery. | |
| From: George Santayana (Platonism and the Spiritual Life [1927], p.3), quoted by John Gray - Seven Types of Atheism 6 | |
| A reaction: That is, he concedes that the good is relative to human beings, but that the relevant facts about human beings are not relative. I think he has the correct picture. The key point is that the good is 'rooted' in something, and doesn't just float free. |
| 15877 | The aim of science is just to create a comprehensive, elegant language to describe brute facts [Poincaré, by Harré] |
| Full Idea: In Poincaré's view, we try to construct a language within which the brute facts of experience are expressed as comprehensively and as elegantly as possible. The job of science is the forging of a language precisely suited to that purpose. | |
| From: report of Henri Poincaré (The Value of Science [1906], Pt III) by Rom Harré - Laws of Nature 2 | |
| A reaction: I'm often struck by how obscure and difficult our accounts of self-evident facts can be. Chairs are easy, and the metaphysics of chairs is hideous. Why is that? I'm a robust realist, but I like Poincaré's idea. He permits facts. |
| 1513 | The Egyptians were the first to say the soul is immortal and reincarnated [Herodotus] |
| Full Idea: The Egyptians were the first to claim that the soul of a human being is immortal, and that each time the body dies the soul enters another creature just as it is being born. | |
| From: Herodotus (The Histories [c.435 BCE], 2.123.2) |