15 ideas
| 11022 | Gentzen introduced a natural deduction calculus (NK) in 1934 [Gentzen, by Read] |
| 11065 | The inferential role of a logical constant constitutes its meaning [Gentzen, by Hanna] |
| 11023 | The logical connectives are 'defined' by their introduction rules [Gentzen] |
| 11213 | Each logical symbol has an 'introduction' rule to define it, and hence an 'elimination' rule [Gentzen] |
| 13832 | Natural deduction shows the heart of reasoning (and sequent calculus is just a tool) [Gentzen, by Hacking] |
| 10067 | Gentzen proved the consistency of arithmetic from assumptions beyond arithmetic [Gentzen, by Musgrave] |
| 5953 | For the Cyrenaics experience was not enough to give certainty about reality [Aristippus young, by Plutarch] |
| 3023 | Even the foolish may have some virtues [Aristippus young, by Diog. Laertius] |
| 3026 | Actions are influenced by circumstances, so Cyrenaics say felons should be reformed, not hated [Aristippus young, by Diog. Laertius] |
| 3024 | Cyrenaics teach that honour, justice and shame are all based on custom and fashion [Aristippus young, by Diog. Laertius] |
| 3025 | For a Cyrenaic no one is of equal importance to himself [Aristippus young, by Diog. Laertius] |
| 3019 | No one pleasure is different from or more pleasant than another [Aristippus young, by Diog. Laertius] |
| 3021 | The Cyrenaics asserted that corporeal pleasures were superior to mental ones [Aristippus young, by Diog. Laertius] |
| 3027 | Cyrenaics say wise men are self-sufficient, needing no friends [Aristippus young, by Diog. Laertius] |
| 20751 | As a young girl assumes her status as feminine, she acts in a more fragile immobile way [Young,IM] |