16 ideas
| 9271 | Human knowledge may not produce well-being; the examined life may not be worth living [Gray] |
| 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] |
| 9275 | Knowledge does not need minds or nervous systems; it is found in all living things [Gray] |
| 9276 | The will hardly ever does anything; most of our life just happens to us [Gray] |
| 9278 | Nowadays we identify the free life with the good life [Gray] |
| 13304 | Learned men gain more in one day than others do in a lifetime [Posidonius] |
| 20820 | Time is an interval of motion, or the measure of speed [Posidonius, by Stobaeus] |
| 9280 | Over forty percent of the Earth's living tissue is human [Gray] |
| 9272 | Without Christianity we lose the idea that human history has a meaning [Gray] |
| 9279 | What was our original sin, and how could Christ's suffering redeem it? [Gray] |