52 ideas
| 6887 | Linguistic philosophy approaches problems by attending to actual linguistic usage [Mautner] |
| 6881 | Analytic philosophy studies the unimportant, and sharpens tools instead of using them [Mautner] |
| 5439 | The 'hermeneutic circle' says parts and wholes are interdependent, and so cannot be interpreted [Mautner] |
| 9959 | 'Real' definitions give the essential properties of things under a concept [Mautner] |
| 10476 | The idea that groups of concepts could be 'implicitly defined' was abandoned [Hodges,W] |
| 9961 | 'Contextual definitions' replace whole statements, not just expressions [Mautner] |
| 9958 | Recursive definition defines each instance from a previous instance [Mautner] |
| 9960 | A stipulative definition lays down that an expression is to have a certain meaning [Mautner] |
| 9957 | Ostensive definitions point to an object which an expression denotes [Mautner] |
| 6219 | The fallacy of composition is the assumption that what is true of the parts is true of the whole [Mautner] |
| 6888 | Fuzzy logic is based on the notion that there can be membership of a set to some degree [Mautner] |
| 13451 | The two best understood conceptions of set are the Iterative and the Limitation of Size [Rayo/Uzquiano] |
| 13452 | Some set theories give up Separation in exchange for a universal set [Rayo/Uzquiano] |
| 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] |
| 6877 | Entailment is logical requirement; it may be not(p and not-q), but that has problems [Mautner] |
| 6880 | Strict implication says false propositions imply everything, and everything implies true propositions [Mautner] |
| 6879 | 'Material implication' is defined as 'not(p and not-q)', but seems to imply a connection between p and q [Mautner] |
| 6878 | A person who 'infers' draws the conclusion, but a person who 'implies' leaves it to the audience [Mautner] |
| 6889 | Vagueness seems to be inconsistent with the view that every proposition is true or false [Mautner] |
| 6890 | Quantifiers turn an open sentence into one to which a truth-value can be assigned [Mautner] |
| 13449 | We could have unrestricted quantification without having an all-inclusive domain [Rayo/Uzquiano] |
| 13450 | Absolute generality is impossible, if there are indefinitely extensible concepts like sets and ordinals [Rayo/Uzquiano] |
| 13453 | Perhaps second-order quantifications cover concepts of objects, rather than plain objects [Rayo/Uzquiano] |
| 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] |
| 10283 | A formula needs an 'interpretation' of its constants, and a 'valuation' of its variables [Hodges,W] |
| 10474 | |= should be read as 'is a model for' or 'satisfies' [Hodges,W] |
| 10475 | A 'structure' is an interpretation specifying objects and classes of quantification [Hodges,W] |
| 10473 | Model theory studies formal or natural language-interpretation using set-theory [Hodges,W] |
| 10481 | Models in model theory are structures, not sets of descriptions [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] |
| 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] |
| 6884 | Counterfactuals say 'If it had been, or were, p, then it would be q' [Mautner] |
| 6882 | Counterfactuals presuppose a belief (or a fact) that the condition is false [Mautner] |
| 6886 | Counterfactuals are not true, they are merely valid [Mautner] |
| 6885 | Counterfactuals are true if in every world close to actual where p is the case, q is also the case [Mautner] |
| 6883 | Maybe counterfactuals are only true if they contain valid inference from premisses [Mautner] |
| 5449 | Essentialism is often identified with belief in 'de re' necessary truths [Mautner] |
| 6898 | Fallibilism is the view that all knowledge-claims are provisional [Mautner] |
| 6452 | 'Sense-data' arrived in 1910, but it denotes ideas in Locke, Berkeley and Hume [Mautner] |
| 4783 | Observing lots of green x can confirm 'all x are green' or 'all x are grue', where 'grue' is arbitrary [Mautner, by PG] |
| 4782 | 'All x are y' is equivalent to 'all non-y are non-x', so observing paper is white confirms 'ravens are black' [Mautner, by PG] |
| 6899 | The references of indexicals ('there', 'now', 'I') depend on the circumstances of utterance [Mautner] |
| 13448 | The domain of an assertion is restricted by context, either semantically or pragmatically [Rayo/Uzquiano] |
| 6896 | Double effect is the distinction between what is foreseen and what is intended [Mautner] |
| 6897 | Double effect acts need goodness, unintended evil, good not caused by evil, and outweighing [Mautner] |
| 5452 | 'Essentialism' is opposed to existentialism, and claims there is a human nature [Mautner] |