3 ideas
| 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. |
| 9992 | The 'extension of a concept' in general may be quantitatively completely indeterminate [Cantor] |
| Full Idea: The author entirely overlooks the fact that the 'extension of a concept' in general may be quantitatively completely indeterminate. Only in certain cases is the 'extension of a concept' quantitatively determinate. | |
| From: George Cantor (Review of Frege's 'Grundlagen' [1885], 1932:440), quoted by William W. Tait - Frege versus Cantor and Dedekind | |
| A reaction: Cantor presumably has in mind various infinite sets. Tait is drawing our attention to the fact that this objection long precedes Russell's paradox, which made the objection more formal (a language Frege could understand!). |
| 23215 | Even the poorest have a life to lead, and so should consent to who governs them [-] |
| Full Idea: For really I think that the poorest hee that is in England hath a life to live, as the greatest hee; …and every Man that is to live under a Government ought first by his own Consent to put himself under that Government. | |
| From: - (The Putney Debates [1647]) | |
| A reaction: [remark made by Thomas Rainsborough] This is the social contract idea which is explicit in Hobbes. I'm sure we can at least trace it back to John Lilburne in the 1630s. |