13 ideas
9193 | ZF set theory has variables which range over sets, 'equals' and 'member', and extensionality [Dummett] |
9194 | The main alternative to ZF is one which includes looser classes as well as sets [Dummett] |
9195 | Intuitionists reject excluded middle, not for a third value, but for possibility of proof [Dummett] |
9186 | First-order logic concerns objects; second-order adds properties, kinds, relations and functions [Dummett] |
9187 | Logical truths and inference are characterized either syntactically or semantically [Dummett] |
9191 | Ordinals seem more basic than cardinals, since we count objects in sequence [Dummett] |
9192 | The number 4 has different positions in the naturals and the wholes, with the same structure [Dummett] |
8983 | If 'red' is vague, then membership of the set of red things is vague, so there is no set of red things [Sainsbury] |
8986 | We should abandon classifying by pigeon-holes, and classify around paradigms [Sainsbury] |
13128 | 'Ultimate sortals' cannot explain ontological categories [Westerhoff on Wiggins] |
8982 | Vague concepts are concepts without boundaries [Sainsbury] |
8984 | If concepts are vague, people avoid boundaries, can't spot them, and don't want them [Sainsbury] |
8985 | Boundaryless concepts tend to come in pairs, such as child/adult, hot/cold [Sainsbury] |