11 ideas
9456 | Modal logic is multiple systems, shown in the variety of accessibility relations between worlds [Jacquette] |
16186 | The Barcan Formulas express how to combine modal operators with classical quantifiers [Simchen] |
16187 | The Barcan Formulas are orthodox, but clash with the attractive Actualist view [Simchen] |
16190 | BF implies that if W possibly had a child, then something is possibly W's child [Simchen] |
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] |
16188 | Serious Actualism says there are no facts at all about something which doesn't exist [Simchen] |
9460 | Extensionalist semantics forbids reference to nonexistent objects [Jacquette] |
9459 | Extensionalist semantics is circular, as we must know the extension before assessing 'Fa' [Jacquette] |
4398 | An event causes another just if the second event would not have happened without the first [Lewis, by Psillos] |