11 ideas
14626 | In S5 matters of possibility and necessity are non-contingent [Williamson] |
21222 | Logicians presuppose a world, and ignore logic/world connections, so their logic is impure [Husserl, by Velarde-Mayol] |
21223 | Phenomenology grounds logic in subjective experience [Husserl, by Velarde-Mayol] |
21224 | Pure mathematics is the relations between all possible objects, and is thus formal ontology [Husserl, by Velarde-Mayol] |
14625 | Necessity is counterfactually implied by its negation; possibility does not counterfactually imply its negation [Williamson] |
14623 | Strict conditionals imply counterfactual conditionals: □(A⊃B)⊃(A□→B) [Williamson] |
14624 | Counterfactual conditionals transmit possibility: (A□→B)⊃(◊A⊃◊B) [Williamson] |
14531 | Rather than define counterfactuals using necessity, maybe necessity is a special case of counterfactuals [Williamson, by Hale/Hoffmann,A] |
14628 | Imagination is important, in evaluating possibility and necessity, via counterfactuals [Williamson] |
1748 | Archelaus was the first person to say that the universe is boundless [Archelaus, by Diog. Laertius] |
5989 | Archelaus said life began in a primeval slime [Archelaus, by Schofield] |