display all the ideas for this combination of texts
3 ideas
| 8994 | If analytic geometry identifies figures with arithmetical relations, logicism can include geometry [Quine] |
| Full Idea: Geometry can be brought into line with logicism simply by identifying figures with arithmetical relations with which they are correlated thought analytic geometry. | |
| From: Willard Quine (Truth by Convention [1935], p.87) | |
| A reaction: Geometry was effectively reduced to arithmetic by Descartes and Fermat, so this seems right. You wonder, though, whether something isn't missing if you treat geometry as a set of equations. There is more on the screen than what's in the software. |
| 8997 | There are four different possible conventional accounts of geometry [Quine] |
| Full Idea: We can construe geometry by 1) identifying it with algebra, which is then defined on the basis of logic; 2) treating it as hypothetical statements; 3) defining it contextually; or 4) making it true by fiat, without making it part of logic. | |
| From: Willard Quine (Truth by Convention [1935], p.99) | |
| A reaction: [Very compressed] I'm not sure how different 3 is from 2. These are all ways to treat geometry conventionally. You could be more traditional, and say that it is a description of actual space, but the multitude of modern geometries seems against this. |
| 8993 | If mathematics follows from definitions, then it is conventional, and part of logic [Quine] |
| Full Idea: To claim that mathematical truths are conventional in the sense of following logically from definitions is the claim that mathematics is a part of logic. | |
| From: Willard Quine (Truth by Convention [1935], p.79) | |
| A reaction: Quine is about to attack logic as convention, so he is endorsing the logicist programme (despite his awareness of Gödel), but resisting the full Wittgenstein conventionalist picture. |