36 ideas
| 10476 | The idea that groups of concepts could be 'implicitly defined' was abandoned [Hodges,W] |
| 10282 | Logic is the study of sound argument, or of certain artificial languages (or applying the latter to the former) [Hodges,W] |
| 10478 | Since first-order languages are complete, |= and |- have the same meaning [Hodges,W] |
| 10477 | |= in model-theory means 'logical consequence' - it holds in all models [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] |
| 10474 | |= should be read as 'is a model for' or 'satisfies' [Hodges,W] |
| 10473 | Model theory studies formal or natural language-interpretation using set-theory [Hodges,W] |
| 10475 | A 'structure' is an interpretation specifying objects and classes of quantification [Hodges,W] |
| 10481 | Models in model theory are structures, not sets of descriptions [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] |
| 10480 | First-order logic can't discriminate between one infinite cardinal and another [Hodges,W] |
| 10286 | A 'set' is a mathematically well-behaved class [Hodges,W] |
| 19542 | It is nonsense that understanding does not involve knowledge; to understand, you must know [Dougherty/Rysiew] |
| 19543 | To grasp understanding, we should be more explicit about what needs to be known [Dougherty/Rysiew] |
| 19541 | Rather than knowledge, our epistemic aim may be mere true belief, or else understanding and wisdom [Dougherty/Rysiew] |
| 19540 | Don't confuse justified belief with justified believers [Dougherty/Rysiew] |
| 19539 | If knowledge is unanalysable, that makes justification more important [Dougherty/Rysiew] |
| 6685 | 'Subjectivism' is an extension of relativism from the social group to the individual [Graham] |
| 19538 | Entailment is modelled in formal semantics as set inclusion (where 'mammals' contains 'cats') [Dougherty/Rysiew] |
| 6699 | The chain of consequences may not be the same as the chain of responsibility [Graham] |
| 6698 | Negative consequences are very hard (and possibly impossible) to assess [Graham] |
| 6700 | We can't criticise people because of unforeseeable consequences [Graham] |
| 6704 | Egoism submits to desires, but cannot help form them [Graham] |
| 6701 | Rescue operations need spontaneous benevolence, not careful thought [Graham] |
| 6693 | 'What if everybody did that?' rather misses the point as an objection to cheating [Graham] |
| 6691 | It is more plausible to say people can choose between values, than that they can create them [Graham] |
| 6688 | Life is only absurd if you expected an explanation and none turns up [Graham] |
| 6705 | Existentialism may transcend our nature, unlike eudaimonism [Graham] |
| 6690 | A standard problem for existentialism is the 'sincere Nazi' [Graham] |
| 6689 | The key to existentialism: the way you make choices is more important than what you choose [Graham] |
| 6706 | The great religions are much more concerned with the religious life than with ethics [Graham] |
| 6709 | Western religion saves us from death; Eastern religion saves us from immortality [Graham] |