29 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] |
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] |
17292 | Avoid 'in virtue of' for grounding, since it might imply a reflexive relation such as identity [Audi,P] |
17295 | Ground relations depend on the properties [Audi,P] |
17297 | A ball's being spherical non-causally determines its power to roll [Audi,P] |
17302 | Ground is irreflexive, asymmetric, transitive, non-monotonic etc. [Audi,P] |
17303 | The best critique of grounding says it is actually either identity or elimination [Audi,P] |
17294 | Grounding is a singular relation between worldly facts [Audi,P] |
17300 | If grounding relates facts, properties must be included, as well as objects [Audi,P] |
17296 | We must accept grounding, for our important explanations [Audi,P] |
17301 | Reduction is just identity, so the two things are the same fact, so reduction isn't grounding [Audi,P] |
17293 | Worldly facts are obtaining states of affairs, with constituents; conceptual facts also depend on concepts [Audi,P] |
17298 | Two things being identical (like water and H2O) is not an explanation [Audi,P] |
17299 | There are plenty of examples of non-causal explanation [Audi,P] |
6005 | Animals are dangerous and nourishing, and can't form contracts of justice [Hermarchus, by Sedley] |