13 ideas
| 21560 | Any linguistic expression may lack meaning when taken out of context [Russell] |
| 21561 | 'The number one is bald' or 'the number one is fond of cream cheese' are meaningless [Russell] |
| 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] |
| 18130 | Axiom of Reducibility: there is always a function of the lowest possible order in a given level [Russell, by Bostock] |
| 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] |
| 21562 | There is no complexity without relations, so no propositions, and no truth [Russell] |
| 8431 | Problems with Goodman's view of counterfactuals led to a radical approach from Stalnaker and Lewis [Horwich] |
| 8432 | Analyse counterfactuals using causation, not the other way around [Horwich] |