3 ideas
| 23367 | Even pointing a finger should only be done for a reason [Epictetus] |
| Full Idea: Philosophy says it is not right even to stretch out a finger without some reason. | |
| From: Epictetus (fragments/reports [c.57], 15) | |
| A reaction: The key point here is that philosophy concerns action, an idea on which Epictetus is very keen. He rather despise theory. This idea perfectly sums up the concept of the wholly rational life (which no rational person would actually want to live!). |
| 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. |
| 18151 | Could we replace sets by the open sentences that define them? [Chihara, by Bostock] |
| Full Idea: Chihara proposes to replace all sets by reference to the open sentences that define them. | |
| From: report of Charles Chihara (Ontology and the Vicious Circle Principle [1973]) by David Bostock - Philosophy of Mathematics 9.B.4 | |
| A reaction: This depends on predicativism, because that stipulates the definitions will be available (cos if it ain't definable it ain't there). Chihara went on to define the open sentences in terms of the possibility of uttering them. Cf. propositional functions. |