17 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] |
| 13430 | Infinity: there is an infinity of distinguishable individuals [Ramsey] |
| 13428 | Reducibility: to every non-elementary function there is an equivalent elementary function [Ramsey] |
| 9195 | Intuitionists reject excluded middle, not for a third value, but for possibility of proof [Dummett] |
| 13427 | Either 'a = b' vacuously names the same thing, or absurdly names different things [Ramsey] |
| 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] |
| 13334 | Contradictions are either purely logical or mathematical, or they involved thought and language [Ramsey] |
| 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] |
| 13426 | Formalists neglect content, but the logicists have focused on generalizations, and neglected form [Ramsey] |
| 13425 | Formalism is hopeless, because it focuses on propositions and ignores concepts [Ramsey] |
| 21846 | Bergson was a rallying point, because he emphasised becomings and multiplicities [Bergson, by Deleuze] |
| 22328 | I just confront the evidence, and let it act on me [Ramsey] |
| 21854 | Bergson showed that memory is not after the event, but coexists with it [Bergson, by Deleuze] |
| 22325 | A belief is knowledge if it is true, certain and obtained by a reliable process [Ramsey] |