15 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] |
| 18617 | Substances, unlike aggregates, can survive a change of parts [Mumford] |
| 18618 | Maybe possibilities are recombinations of the existing elements of reality [Mumford] |
| 18619 | Combinatorial possibility has to allow all elements to be combinable, which seems unlikely [Mumford] |
| 18620 | Combinatorial possibility relies on what actually exists (even over time), but there could be more [Mumford] |
| 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] |