40 ideas
9550 | We only know relational facts about the empty set, but nothing intrinsic [Chihara] |
9562 | In simple type theory there is a hierarchy of null sets [Chihara] |
9573 | The null set is a structural position which has no other position in membership relation [Chihara] |
9572 | Realists about sets say there exists a null set in the real world, with no members [Chihara] |
9551 | What is special about Bill Clinton's unit set, in comparison with all the others? [Chihara] |
9549 | The set theorist cannot tell us what 'membership' is [Chihara] |
9571 | ZFU refers to the physical world, when it talks of 'urelements' [Chihara] |
9563 | A pack of wolves doesn't cease when one member dies [Chihara] |
18739 | Three stages of philosophical logic: syntactic (1905-55), possible worlds (1963-85), widening (1990-) [Horsten/Pettigrew] |
18741 | Logical formalization makes concepts precise, and also shows their interrelation [Horsten/Pettigrew] |
9561 | The mathematics of relations is entirely covered by ordered pairs [Chihara] |
18744 | Models are sets with functions and relations, and truth built up from the components [Horsten/Pettigrew] |
9552 | Sentences are consistent if they can all be true; for Frege it is that no contradiction can be deduced [Chihara] |
9553 | Analytic geometry gave space a mathematical structure, which could then have axioms [Chihara] |
10192 | We can replace existence of sets with possibility of constructing token sentences [Chihara, by MacBride] |
18740 | If 'exist' doesn't express a property, we can hardly ask for its essence [Horsten/Pettigrew] |
9559 | If a successful theory confirms mathematics, presumably a failed theory disconfirms it? [Chihara] |
9566 | No scientific explanation would collapse if mathematical objects were shown not to exist [Chihara] |
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] |
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] |
18745 | A Tarskian model can be seen as a possible state of affairs [Horsten/Pettigrew] |
18747 | The 'spheres model' was added to possible worlds, to cope with counterfactuals [Horsten/Pettigrew] |
18748 | Epistemic logic introduced impossible worlds [Horsten/Pettigrew] |
18746 | Possible worlds models contain sets of possible worlds; this is a large metaphysical commitment [Horsten/Pettigrew] |
18750 | Using possible worlds for knowledge and morality may be a step too far [Horsten/Pettigrew] |
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] |
9568 | I prefer the open sentences of a Constructibility Theory, to Platonist ideas of 'equivalence classes' [Chihara] |
14071 | Naming a thing in the actual world also invokes some persistence criteria [Gibbard] |
9547 | Mathematical entities are causally inert, so the causal theory of reference won't work for them [Chihara] |
9574 | 'Gunk' is an individual possessing no parts that are atoms [Chihara] |