6 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. |
| 18189 | ZFC could contain a contradiction, and it can never prove its own consistency [MacLane] |
| Full Idea: We have at hand no proof that the axioms of ZFC for set theory will never yield a contradiction, while Gödel's second theorem tells us that such a consistency proof cannot be conducted within ZFC. | |
| From: Saunders MacLane (Mathematics: Form and Function [1986], p.406), quoted by Penelope Maddy - Naturalism in Mathematics | |
| A reaction: Maddy quotes this, while defending set theory as the foundation of mathematics, but it clearly isn't the most secure foundation that could be devised. She says the benefits of set theory do not need guaranteed consistency (p.30). |
| 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. |
| 7458 | The reliability of witnesses depends on whether they benefit from their observations [Laplace, by Hacking] |
| Full Idea: The credibility of a witness is in part a function of the story being reported. When the story claims to have infinite value, the temptation to lie for personal benefit is asymptotically infinite. | |
| From: report of Pierre Simon de Laplace (Philosophical Essay on Probability [1820], Ch.XI) by Ian Hacking - The Emergence of Probability Ch.8 | |
| A reaction: Laplace seems to especially have reports of miracles in mind. This observation certainly dashes any dreams one might have of producing a statistical measure of the reliability of testimony. |
| 3441 | If a supreme intellect knew all atoms and movements, it could know all of the past and the future [Laplace] |
| Full Idea: An intelligence knowing at an instant the whole universe could know the movement of the largest bodies and atoms in one formula, provided his intellect were powerful enough to subject all data to analysis. Past and future would be present to his eyes. | |
| From: Pierre Simon de Laplace (Philosophical Essay on Probability [1820]), quoted by Mark Thornton - Do we have free will? p.70 |
| 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. |