18 ideas
23623 | Predicativism says only predicated sets exist [Hossack] |
23624 | The iterative conception has to appropriate Replacement, to justify the ordinals [Hossack] |
23625 | Limitation of Size justifies Replacement, but then has to appropriate Power Set [Hossack] |
18755 | Validity is explained as truth in all models, because that relies on the logical terms [McGee] |
19043 | Bivalence applies not just to sentences, but that general terms are true or false of each object [Quine] |
18751 | Natural language includes connectives like 'because' which are not truth-functional [McGee] |
23628 | The connective 'and' can have an order-sensitive meaning, as 'and then' [Hossack] |
23627 | 'Before' and 'after' are not two relations, but one relation with two orders [Hossack] |
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] |
23626 | Transfinite ordinals are needed in proof theory, and for recursive functions and computability [Hossack] |
18760 | The culmination of Euclidean geometry was axioms that made all models isomorphic [McGee] |
23621 | Numbers are properties, not sets (because numbers are magnitudes) [Hossack] |
23622 | We can only mentally construct potential infinities, but maths needs actual infinities [Hossack] |
19042 | Terms learned by ostension tend to be vague, because that must be quick and unrefined [Quine] |
18762 | A maxim claims that if we are allowed to assert a sentence, that means it must be true [McGee] |