51 ideas
13252 | Some truths have true negations [Beall/Restall] |
13247 | A truthmaker is an object which entails a sentence [Beall/Restall] |
10688 | 'Equivocation' is when terms do not mean the same thing in premises and conclusion [Beall/Restall] |
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] |
13242 | It's 'relevantly' valid if all those situations make it true [Beall/Restall] |
13246 | Relevant logic does not abandon classical logic [Beall/Restall] |
13245 | Relevant consequence says invalidity is the conclusion not being 'in' the premises [Beall/Restall] |
13254 | A doesn't imply A - that would be circular [Beall/Restall] |
13255 | Relevant logic may reject transitivity [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13234 | The view of logic as knowing a body of truths looks out-of-date [Beall/Restall] |
10690 | Formal logic is invariant under permutations, or devoid of content, or gives the norms for thought [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] |
10691 | Logical consequence needs either proofs, or absence of counterexamples [Beall/Restall] |
13253 | There are several different consequence relations [Beall/Restall] |
13240 | A sentence follows from others if they always model it [Beall/Restall] |
10695 | Logical consequence is either necessary truth preservation, or preservation based on interpretation [Beall/Restall] |
10689 | A step is a 'material consequence' if we need contents as well as form [Beall/Restall] |
10696 | A 'logical truth' (or 'tautology', or 'theorem') follows from empty premises [Beall/Restall] |
13236 | Logical truth is much more important if mathematics rests on it, as logicism claims [Beall/Restall] |
10693 | Models are mathematical structures which interpret the non-logical primitives [Beall/Restall] |
13237 | Preface Paradox affirms and denies the conjunction of propositions in the book [Beall/Restall] |
10692 | Hilbert proofs have simple rules and complex axioms, and natural deduction is the opposite [Beall/Restall] |
16062 | A necessary relation between fact-levels seems to be a further irreducible fact [Lynch/Glasgow] |
16061 | If some facts 'logically supervene' on some others, they just redescribe them, adding nothing [Lynch/Glasgow] |
16060 | Nonreductive materialism says upper 'levels' depend on lower, but don't 'reduce' [Lynch/Glasgow] |
16064 | The hallmark of physicalism is that each causal power has a base causal power under it [Lynch/Glasgow] |
1212 | Replacing timbers on Theseus' ship was the classic illustration of the problem of growth and change [Plutarch] |
13244 | Relevant necessity is always true for some situation (not all situations) [Beall/Restall] |
5958 | The sun is always bright; it doesn't become bright when it emerges [Plutarch] |
5959 | Some philosophers say the soul is light [Plutarch] |
5960 | When the soul is intelligent and harmonious, it is part of god and derives from god [Plutarch] |
5952 | Rather than being the whole soul, maybe I am its chief part? [Plutarch] |
5951 | If atoms have no qualities, they cannot possibly produce a mind [Plutarch] |
5963 | Some say emotion is a sort of reason, and others say virtue concerns emotion [Plutarch] |
13239 | Judgement is always predicating a property of a subject [Beall/Restall] |
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] |
20796 | Action needs an affinity for a presentation, and an impulse toward the affinity [Plutarch] |
1477 | Being manly and brave is the result of convention, not of human nature [Plutarch] |
1478 | Animals don't value pleasure, as they cease sexual intercourse after impregnation [Plutarch] |
5948 | The good life involves social participation, loyalty, temperance and honesty [Plutarch] |
1479 | Animals have not been led into homosexuality, because they value pleasure very little [Plutarch] |
5950 | If only atoms exist, how do qualities arise when the atoms come together? [Plutarch] |
5974 | People report seeing through rocks, or over the horizon, or impossibly small works [Plutarch] |
5957 | Absurd superstitions make people atheist, not disharmony in nature [Plutarch] |
5955 | No one will ever find a city that lacks religious practices [Plutarch] |