22 ideas
1597 | Thales was the first western thinker to believe the arché was intelligible [Roochnik on Thales] |
16951 | It was realised that possible worlds covered all modal logics, if they had a structure [Dummett] |
16953 | Relative possibility one way may be impossible coming back, so it isn't symmetrical [Dummett] |
16952 | If something is only possible relative to another possibility, the possibility relation is not transitive [Dummett] |
16960 | If possibilitiy is relative, that might make accessibility non-transitive, and T the correct system [Dummett] |
16958 | In S4 the actual world has a special place [Dummett] |
18755 | Validity is explained as truth in all models, because that relies on the logical terms [McGee] |
18751 | Natural language includes connectives like 'because' which are not truth-functional [McGee] |
18761 | Second-order variables need to range over more than collections of first-order objects [McGee] |
18753 | An ontologically secure semantics for predicate calculus relies on sets [McGee] |
18754 | Logically valid sentences are analytic truths which are just true because of their logical words [McGee] |
18757 | Soundness theorems are uninformative, because they rely on soundness in their proofs [McGee] |
18760 | The culmination of Euclidean geometry was axioms that made all models isomorphic [McGee] |
3013 | Nothing is stronger than necessity, which rules everything [Thales, by Diog. Laertius] |
16957 | Possible worlds aren't how the world might be, but how a world might be, given some possibility [Dummett] |
16959 | If possible worlds have no structure (S5) they are equal, and it is hard to deny them reality [Dummett] |
18762 | A maxim claims that if we are allowed to assert a sentence, that means it must be true [McGee] |
16956 | To explain generosity in a person, you must understand a generous action [Dummett] |
1494 | Thales said water is the first principle, perhaps from observing that food is moist [Thales, by Aristotle] |
16954 | Generalised talk of 'natural kinds' is unfortunate, as they vary too much [Dummett] |
1713 | Thales must have thought soul causes movement, since he thought magnets have soul [Thales, by Aristotle] |
1742 | Thales said the gods know our wrong thoughts as well as our evil actions [Thales, by Diog. Laertius] |