3 ideas
| 15380 | Barcan:nothing comes into existence; Converse:nothing goes out; Both:domain is unchanging [Vervloesem] |
| Full Idea: Intuitively, the Barcan formula says that nothing comes into existence when moving from a possible world to an alternative world. The converse says that nothing goes out of existence. Together they say the domain of quantification is fixed for all worlds. | |
| From: Koen Vervloesem (Barcan Formulae [2010]) | |
| A reaction: Stated so clearly, they sound absurd. The sensible idea, I suppose, is that you can refer to all the things from any world, but that doesn't mean they are possible. Shades of Meinong. 'Square circles' are not possible. |
| 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. |
| 14933 | Scientific properties are defined by the laws that embody them [Psillos, by Ladyman/Ross] |
| Full Idea: For Psillos, properties in mature science are defined by the laws in which they feature. | |
| From: report of Stathis Psillos (Scientific Realism [1999]) by J Ladyman / D Ross - Every Thing Must Go 3.5 | |
| A reaction: This is a perfect example of the Humean approach getting everything the wrong way round. Laws are not primitives from which we derive our account of nature - they are generalisations built up from the behaviour of prior properties. |