11 ideas
10163 | Propositional modal logic has been proved to be complete [Kripke, by Feferman/Feferman] |
10760 | With possible worlds, S4 and S5 are sound and complete, but S1-S3 are not even sound [Kripke, by Rossberg] |
16189 | The variable domain approach to quantified modal logic invalidates the Barcan Formula [Kripke, by Simchen] |
15132 | The Barcan formulas fail in models with varying domains [Kripke, by Williamson] |
14221 | Serious essentialism says everything has essences, they're not things, and they ground necessities [Shalkowski] |
14222 | Essences are what it is to be that (kind of) thing - in fact, they are the thing's identity [Shalkowski] |
14226 | We distinguish objects by their attributes, not by their essences [Shalkowski] |
14225 | Critics say that essences are too mysterious to be known [Shalkowski] |
14223 | De dicto necessity has linguistic entities as their source, so it is a type of de re necessity [Shalkowski] |
1556 | By nature people are close to one another, but culture drives them apart [Hippias] |
14224 | Equilateral and equiangular aren't the same, as we have to prove their connection [Shalkowski] |