3 ideas
| 9355 | One sort of circularity presupposes a premise, the other presupposes a rule being used [Braithwaite, by Devitt] |
| Full Idea: An argument is 'premise-circular' if it aims to establish a conclusion that is assumed as a premise of that very argument. An argument is 'rule-circular' if it aims to establish a conclusion that asserts the goodness of the rule used in that argument. | |
| From: report of R.B. Braithwaite (Scientific Explanation [1953], p.274-8) by Michael Devitt - There is no a Priori §2 | |
| A reaction: Rule circularity is the sort of thing Quine is always objecting to, but such circularities may be unavoidable, and even totally benign. All the good things in life form a mutually supporting team. |
| 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. |
| 16157 | Insurance on the original ship would hardly be paid out if the plank version was wrecked! [Frede,M] |
| Full Idea: No insurance company, presented with a policy written for 'Theoris' [the original ship] would pay for damages suffered if the ship contructed from the old planks had been shipwrecked. | |
| From: Michael Frede (Individuals in Aristotle [1978]) | |
| A reaction: A very nicely dramatic way of presenting what is taken to be the usual reading of the basic case - that the original identity tracks the continuity of the original structure, not the matter. |