30 ideas
14001 | People who use science to make philosophical points don't realise how philosophical science is [Markosian] |
10476 | The idea that groups of concepts could be 'implicitly defined' was abandoned [Hodges,W] |
13991 | Presentism has the problem that if Socrates ceases to exist, so do propositions about him [Markosian] |
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] |
14002 | Possible worlds must be abstract, because two qualitatively identical worlds are just one world [Markosian] |
8044 | Goffman sees the self as no more than a peg on which to hang roles we play [Goffman, by MacIntyre] |
14000 | 'Grabby' truth conditions first select their object, unlike 'searchy' truth conditions [Markosian] |
13990 | Presentism is the view that only present objects exist [Markosian] |
13992 | Presentism says if objects don't exist now, we can't have attitudes to them or relations with them [Markosian] |
13994 | Presentism seems to entail that we cannot talk about other times [Markosian] |
13995 | Serious Presentism says things must exist to have relations and properties; Unrestricted version denies this [Markosian] |
13996 | Maybe Presentists can refer to the haecceity of a thing, after the thing itself disappears [Markosian] |
13997 | Maybe Presentists can paraphrase singular propositions about the past [Markosian] |
13993 | Special Relativity denies the absolute present which Presentism needs [Markosian] |
13998 | Objects in the past, like Socrates, are more like imaginary objects than like remote spatial objects [Markosian] |
13999 | People are mistaken when they think 'Socrates was a philosopher' says something [Markosian] |