16 ideas
14626 | In S5 matters of possibility and necessity are non-contingent [Williamson] |
16014 | It is controversial whether only 'numerical identity' allows two things to be counted as one [Noonan] |
16024 | I could have died at five, but the summation of my adult stages could not [Noonan] |
16023 | Stage theorists accept four-dimensionalism, but call each stage a whole object [Noonan] |
16015 | Problems about identity can't even be formulated without the concept of identity [Noonan] |
16017 | Identity is usually defined as the equivalence relation satisfying Leibniz's Law [Noonan] |
16016 | Identity definitions (such as self-identity, or the smallest equivalence relation) are usually circular [Noonan] |
16020 | Identity can only be characterised in a second-order language [Noonan] |
16018 | Indiscernibility is basic to our understanding of identity and distinctness [Noonan] |
16019 | Leibniz's Law must be kept separate from the substitutivity principle [Noonan] |
14625 | Necessity is counterfactually implied by its negation; possibility does not counterfactually imply its negation [Williamson] |
14528 | Maybe modal thought is unavoidable, as a priori recognition of necessary truth-preservation in reasoning [Hale/Hoffmann,A] |
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] |