39 ideas
10476 | The idea that groups of concepts could be 'implicitly defined' was abandoned [Hodges,W] |
4901 | Truth has to be correspondence to facts, and a match between relations of ideas and relations in the world [Perry] |
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] |
12750 | The question is whether force is self-sufficient in bodies, and essential, or dependent on something [Lenfant] |
4885 | Identity is a very weak relation, which doesn't require interdefinability, or shared properties [Perry] |
12155 | Statements of 'relative identity' are really statements of resemblance [Perry] |
4899 | Possible worlds thinking has clarified the logic of modality, but is problematic in epistemology [Perry] |
4898 | Possible worlds are indices for a language, or concrete realities, or abstract possibilities [Perry] |
12149 | Indexicals are a problem for beliefs being just subject-proposition relations [Perry] |
4887 | We try to cause other things to occur by causing mental events to occur [Perry] |
4884 | Brain states must be in my head, and yet the pain seems to be in my hand [Perry] |
4888 | It seems plausible that many animals have experiences without knowing about them [Perry] |
4891 | If epiphenomenalism just says mental events are effects but not causes, it is consistent with physicalism [Perry] |
4900 | Prior to Kripke, the mind-brain identity theory usually claimed that the identity was contingent [Perry] |
4892 | If physicalists stick with identity (not supervenience), Martian pain will not be like ours [Perry] |
16391 | Indexical thoughts are about themselves, and ascribe properties to themselves [Perry, by Recanati] |
4889 | Although we may classify ideas by content, we individuate them differently, as their content can change [Perry] |
4896 | The intension of an expression is a function from possible worlds to an appropriate extension [Perry] |
12151 | If we replace 'I' in sentences about me, they are different beliefs and explanations of behaviour [Perry] |
18412 | Indexicals individuate certain belief states, helping in explanation and prediction [Perry] |
4897 | A proposition is a set of possible worlds for which its intension delivers truth [Perry] |
12150 | Indexicals reveal big problems with the traditional idea of a proposition [Perry] |
4890 | A sharp analytic/synthetic line can rarely be drawn, but some concepts are central to thought [Perry] |
15203 | Tense is essential for thought and action [Perry, by Le Poidevin] |
15204 | Actual tensed sentences cannot be tenseless, because they can cite their own context [Perry, by Le Poidevin] |