20 ideas
9456 | Modal logic is multiple systems, shown in the variety of accessibility relations between worlds [Jacquette] |
18823 | To say there could have been people who don't exist, but deny those possible things, rejects Barcan [Stalnaker, by Rumfitt] |
9457 | The two main views in philosophy of logic are extensionalism and intensionalism [Jacquette] |
9458 | Extensionalists say that quantifiers presuppose the existence of their objects [Jacquette] |
9461 | Intensionalists say meaning is determined by the possession of properties [Jacquette] |
11184 | Aristotelian essentialism is about shared properties, individuating essentialism about distinctive properties [Marcus (Barcan)] |
11181 | Aristotelian essentialism involves a 'natural' or 'causal' interpretation of modal operators [Marcus (Barcan)] |
11180 | Essentialist sentences are not theorems of modal logic, and can even be false [Marcus (Barcan)] |
11186 | 'Essentially' won't replace 'necessarily' for vacuous properties like snub-nosed or self-identical [Marcus (Barcan)] |
11185 | 'Is essentially' has a different meaning from 'is necessarily', as they often cannot be substituted [Marcus (Barcan)] |
11182 | If essences are objects with only essential properties, they are elusive in possible worlds [Marcus (Barcan)] |
11183 | The use of possible worlds is to sort properties (not to individuate objects) [Marcus (Barcan)] |
11187 | In possible worlds, names are just neutral unvarying pegs for truths and predicates [Marcus (Barcan)] |
16409 | Unlike Lewis, I defend an actualist version of counterpart theory [Stalnaker] |
16411 | If possible worlds really differ, I can't be in more than one at a time [Stalnaker] |
16412 | If counterparts exist strictly in one world only, this seems to be extreme invariant essentialism [Stalnaker] |
9460 | Extensionalist semantics forbids reference to nonexistent objects [Jacquette] |
9459 | Extensionalist semantics is circular, as we must know the extension before assessing 'Fa' [Jacquette] |
16410 | Extensional semantics has individuals and sets; modal semantics has intensions, functions of world to extension [Stalnaker] |
11189 | Dispositional essences are special, as if an object loses them they cease to exist [Marcus (Barcan)] |