14 ideas
| 21054 | Reason enables the unbounded extension of our rules and intentions [Kant] |
| 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] |
| 10289 | Up Löwenheim-Skolem: if infinite models, then arbitrarily large models [Hodges,W] |
| 10288 | Down Löwenheim-Skolem: if a countable language has a consistent theory, that has a countable model [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] |
| 12583 | Belief truth-conditions are normal circumstances where the belief is supposed to occur [Papineau] |
| 21053 | The manifest will in the world of phenomena has to conform to the laws of nature [Kant] |
| 21055 | Our aim is a constitution which combines maximum freedom with strong restraint [Kant] |
| 21056 | The vitality of business needs maximum freedom (while avoiding harm to others) [Kant] |
| 21057 | The highest ideal of social progress is a universal cosmopolitan existence [Kant] |