15 ideas
7823 | Lucretius was rediscovered in 1417 [Grayling] |
10282 | Logic is the study of sound argument, or of certain artificial languages (or applying the latter to the former) [Hodges,W] |
10283 | A formula needs an 'interpretation' of its constants, and a 'valuation' of its variables [Hodges,W] |
10284 | There are three different standard presentations of semantics [Hodges,W] |
10285 | I |= φ means that the formula φ is true in the interpretation I [Hodges,W] |
10288 | Down Löwenheim-Skolem: if a countable language has a consistent theory, that has a countable model [Hodges,W] |
10289 | Up Löwenheim-Skolem: if infinite models, then arbitrarily large models [Hodges,W] |
10287 | If a first-order theory entails a sentence, there is a finite subset of the theory which entails it [Hodges,W] |
10286 | A 'set' is a mathematically well-behaved class [Hodges,W] |
468 | Musical performance can reveal a range of virtues [Damon of Ath.] |
7809 | In an honour code shame is the supreme punishment, and revenge is a duty [Grayling] |
7824 | If suicide is lawful, but assisting suicide is unlawful, powerless people are denied their rights [Grayling] |
7819 | Religion gives answers, comforts, creates social order, and panders to superstition [Grayling] |
7817 | To make an afterlife appealing, this life has to be denigrated [Grayling] |
7818 | In Greek mythology only heroes can go to heaven [Grayling] |