18 ideas
| 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] |
| 19393 | What is not active is nothing [Leibniz] |
| 7647 | The imagination alone perceives all objects; it is the soul, playing all its roles [La Mettrie] |
| 7645 | When falling asleep, the soul becomes paralysed and weak, just like the body [La Mettrie] |
| 23225 | The soul's faculties depend on the brain, and are simply the brain's organisation [La Mettrie] |
| 7652 | Man is a machine, and there exists only one substance, diversely modified [La Mettrie] |
| 7650 | All thought is feeling, and rationality is the sensitive soul contemplating reasoning [La Mettrie] |
| 7651 | With wonderful new machines being made, a speaking machine no longer seems impossible [La Mettrie] |
| 7648 | The sun and rain weren't made for us; they sometimes burn us, or spoil our seeds [La Mettrie] |
| 7646 | There is no abrupt transition from man to animal; only language has opened a gap [La Mettrie] |
| 7649 | There is no clear idea of the soul, which should only refer to our thinking part [La Mettrie] |