11 ideas
9456 | Modal logic is multiple systems, shown in the variety of accessibility relations between worlds [Jacquette] |
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] |
12205 | There are two families of modal notions, metaphysical and epistemic, of equal strength [Edgington] |
12207 | Metaphysical possibility is discovered empirically, and is contrained by nature [Edgington] |
12206 | Broadly logical necessity (i.e. not necessarily formal logical necessity) is an epistemic notion [Edgington] |
12208 | An argument is only valid if it is epistemically (a priori) necessary [Edgington] |
9460 | Extensionalist semantics forbids reference to nonexistent objects [Jacquette] |
9459 | Extensionalist semantics is circular, as we must know the extension before assessing 'Fa' [Jacquette] |
9425 | Lewis later proposed the axioms at the intersection of the best theories (which may be few) [Mumford on Lewis] |