22 ideas
14970 | Normal system K has five axioms and rules [Cresswell] |
14971 | D is valid on every serial frame, but not where there are dead ends [Cresswell] |
14972 | S4 has 14 modalities, and always reduces to a maximum of three modal operators [Cresswell] |
14973 | In S5 all the long complex modalities reduce to just three, and their negations [Cresswell] |
14976 | Reject the Barcan if quantifiers are confined to worlds, and different things exist in other worlds [Cresswell] |
14974 | A relation is 'Euclidean' if aRb and aRc imply bRc [Cresswell] |
14064 | If a statue is identical with the clay of which it is made, that identity is contingent [Gibbard] |
14066 | A 'piece' of clay begins when its parts stick together, separately from other clay [Gibbard] |
14067 | Clay and statue are two objects, which can be named and reasoned about [Gibbard] |
14069 | We can only investigate the identity once we have designated it as 'statue' or as 'clay' [Gibbard] |
14076 | Essentialism is the existence of a definite answer as to whether an entity fulfils a condition [Gibbard] |
14077 | Essentialism for concreta is false, since they can come apart under two concepts [Gibbard] |
16209 | How can point-duration slices of people have beliefs or desires? [Thomson] |
14070 | A particular statue has sortal persistence conditions, so its origin defines it [Gibbard] |
14073 | Claims on contingent identity seem to violate Leibniz's Law [Gibbard] |
14065 | Two identical things must share properties - including creation and destruction times [Gibbard] |
14074 | Leibniz's Law isn't just about substitutivity, because it must involve properties and relations [Gibbard] |
14975 | A de dicto necessity is true in all worlds, but not necessarily of the same thing in each world [Cresswell] |
14072 | Possible worlds identity needs a sortal [Gibbard] |
14078 | Only concepts, not individuals, can be the same across possible worlds [Gibbard] |
14079 | Kripke's semantics needs lots of intuitions about which properties are essential [Gibbard] |
14071 | Naming a thing in the actual world also invokes some persistence criteria [Gibbard] |