12 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] |
| 23647 | Objects have an essential constitution, producing its qualities, which we are too ignorant to define [Reid] |
| 11958 | Impossibilites are easily conceived in mathematics and geometry [Reid, by Molnar] |
| 1490 | You would have to be very morally lazy to ignore criticisms of your own culture [Nagel] |
| 23646 | Reference is by name, or a term-plus-circumstance, or ostensively, or by description [Reid] |
| 23645 | A word's meaning is the thing conceived, as fixed by linguistic experts [Reid] |