29 ideas
10476 | The idea that groups of concepts could be 'implicitly defined' was abandoned [Hodges,W] |
14231 | We should always apply someone's theory of meaning to their own utterances [Liggins] |
17325 | Truth-maker theory can't cope with non-causal dependence [Liggins] |
17318 | Truthmakers for existence is fine; otherwise maybe restrict it to synthetic truths? [Liggins] |
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] |
14232 | We normally formalise 'There are Fs' with singular quantification and predication, but this may be wrong [Liggins] |
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] |
17320 | Either p is true or not-p is true, so something is true, so something exists [Liggins] |
17326 | The dependence of {Socrates} on Socrates involves a set and a philosopher, not facts [Liggins] |
17327 | Non-causal dependence is at present only dimly understood [Liggins] |
17322 | Necessities supervene on everything, but don't depend on everything [Liggins] |
14233 | Nihilists needn't deny parts - they can just say that some of the xs are among the ys [Liggins] |
17324 | 'Because' can signal an inference rather than an explanation [Liggins] |
17321 | Value, constitution and realisation are non-causal dependences that explain [Liggins] |
17323 | If explanations track dependence, then 'determinative' explanations seem to exist [Liggins] |
3031 | The greatest good is not the achievement of desire, but to desire what is proper [Menedemus, by Diog. Laertius] |