31 ideas
14018 | Is Sufficient Reason self-refuting (no reason to accept it!), or is it a legitimate explanatory tool? [Bourne] |
10476 | The idea that groups of concepts could be 'implicitly defined' was abandoned [Hodges,W] |
14008 | The redundancy theory conflates metalinguistic bivalence with object-language excluded middle [Bourne] |
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] |
14010 | All relations between spatio-temporal objects are either spatio-temporal, or causal [Bourne] |
14009 | It is a necessary condition for the existence of relations that both of the relata exist [Bourne] |
3031 | The greatest good is not the achievement of desire, but to desire what is proper [Menedemus, by Diog. Laertius] |
14016 | The idea of simultaneity in Special Relativity is full of verificationist assumptions [Bourne] |
14019 | Relativity denies simultaneity, so it needs past, present and future (unlike Presentism) [Bourne] |
14013 | Special Relativity allows an absolute past, future, elsewhere and simultaneity [Bourne] |
14015 | No-Futurists believe in past and present, but not future, and say the world grows as facts increase [Bourne] |
14007 | How can presentists talk of 'earlier than', and distinguish past from future? [Bourne] |
14011 | Presentism seems to deny causation, because the cause and the effect can never coexist [Bourne] |
14017 | Since presentists treat the presentness of events as basic, simultaneity should be define by that means [Bourne] |
14003 | Time is tensed or tenseless; the latter says all times and objects are real, and there is no passage of time [Bourne] |
14005 | B-series objects relate to each other; A-series objects relate to the present [Bourne] |
14006 | Time flows, past is fixed, future is open, future is feared but not past, we remember past, we plan future [Bourne] |