44 ideas
20771 | Six parts: dialectic, rhetoric, ethics, politics, physics, theology [Cleanthes, by Diog. Laertius] |
22285 | Impredicative definitions are circular, but fine for picking out, rather than creating something [Potter] |
13252 | Some truths have true negations [Beall/Restall] |
22301 | The Identity Theory says a proposition is true if it coincides with what makes it true [Potter] |
13247 | A truthmaker is an object which entails a sentence [Beall/Restall] |
22324 | It has been unfortunate that externalism about truth is equated with correspondence [Potter] |
13249 | (∀x)(A v B) |- (∀x)A v (∃x)B) is valid in classical logic but invalid intuitionistically [Beall/Restall] |
13243 | Excluded middle must be true for some situation, not for all situations [Beall/Restall] |
13245 | Relevant consequence says invalidity is the conclusion not being 'in' the premises [Beall/Restall] |
13246 | Relevant logic does not abandon classical logic [Beall/Restall] |
13254 | A doesn't imply A - that would be circular [Beall/Restall] |
13255 | Relevant logic may reject transitivity [Beall/Restall] |
13242 | It's 'relevantly' valid if all those situations make it true [Beall/Restall] |
13250 | Free logic terms aren't existential; classical is non-empty, with referring names [Beall/Restall] |
13235 | Logic studies consequence; logical truths are consequences of everything, or nothing [Beall/Restall] |
13238 | Syllogisms are only logic when they use variables, and not concrete terms [Beall/Restall] |
13234 | The view of logic as knowing a body of truths looks out-of-date [Beall/Restall] |
13232 | Logic studies arguments, not formal languages; this involves interpretations [Beall/Restall] |
13241 | The model theory of classical predicate logic is mathematics [Beall/Restall] |
13253 | There are several different consequence relations [Beall/Restall] |
22279 | Frege's sign |--- meant judgements, but the modern |- turnstile means inference, with intecedents [Potter] |
13240 | A sentence follows from others if they always model it [Beall/Restall] |
22291 | Deductivism can't explain how the world supports unconditional conclusions [Potter] |
22295 | Modern logical truths are true under all interpretations of the non-logical words [Potter] |
13236 | Logical truth is much more important if mathematics rests on it, as logicism claims [Beall/Restall] |
13237 | Preface Paradox affirms and denies the conjunction of propositions in the book [Beall/Restall] |
22310 | The formalist defence against Gödel is to reject his metalinguistic concept of truth [Potter] |
22298 | Why is fictional arithmetic applicable to the real world? [Potter] |
22287 | If 'concrete' is the negative of 'abstract', that means desires and hallucinations are concrete [Potter] |
22284 | 'Greater than', which is the ancestral of 'successor', strictly orders the natural numbers [Potter] |
13244 | Relevant necessity is always true for some situation (not all situations) [Beall/Restall] |
22281 | A material conditional cannot capture counterfactual reasoning [Potter] |
22327 | Knowledge from a drunken schoolteacher is from a reliable and unreliable process [Potter] |
6028 | Bodies interact with other bodies, and cuts cause pain, and shame causes blushing, so the soul is a body [Cleanthes, by Nemesius] |
20831 | The soul suffers when the body hurts, creates redness from shame, and pallor from fear [Cleanthes] |
13239 | Judgement is always predicating a property of a subject [Beall/Restall] |
22273 | Traditionally there are twelve categories of judgement, in groups of three [Potter] |
22290 | The phrase 'the concept "horse"' can't refer to a concept, because it is saturated [Potter] |
22283 | Compositionality should rely on the parsing tree, which may contain more than sentence components [Potter] |
22282 | 'Direct compositonality' says the components wholly explain a sentence meaning [Potter] |
22296 | Compositionality is more welcome in logic than in linguistics (which is more contextual) [Potter] |
13248 | We can rest truth-conditions on situations, rather than on possible worlds [Beall/Restall] |
13233 | Propositions commit to content, and not to any way of spelling it out [Beall/Restall] |
5993 | The ascending scale of living creatures requires a perfect being [Cleanthes, by Tieleman] |