17 ideas
10282 | Logic is the study of sound argument, or of certain artificial languages (or applying the latter to the former) [Hodges,W] |
9455 | Maybe proper names have the content of fixing a thing's category [Bealer] |
9454 | The four leading theories of definite descriptions are Frege's, Russell's, Evans's, and Prior's [Bealer] |
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] |
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] |
10286 | A 'set' is a mathematically well-behaved class [Hodges,W] |
13856 | Conditionals are truth-functional, but we must take care with misleading ones [Grice, by Edgington] |
8948 | The odd truth table for material conditionals is explained by conversational conventions [Grice, by Fisher] |
13767 | Conditionals might remain truth-functional, despite inappropriate conversational remarks [Edgington on Grice] |
14277 | A person can be justified in believing a proposition, though it is unreasonable to actually say it [Grice, by Edgington] |
9453 | Sentences saying the same with the same rigid designators may still express different propositions [Bealer] |
9452 | Propositions might be reduced to functions (worlds to truth values), or ordered sets of properties and relations [Bealer] |
9451 | Modal logic and brain science have reaffirmed traditional belief in propositions [Bealer] |