50 ideas
20771 | Six parts: dialectic, rhetoric, ethics, politics, physics, theology [Cleanthes, by Diog. Laertius] |
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13234 | The view of logic as knowing a body of truths looks out-of-date [Beall/Restall] |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] |
13244 | Relevant necessity is always true for some situation (not all situations) [Beall/Restall] |
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] |
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] |
22673 | Wherever there is a small community, the association of the people is natural [Tocqueville] |
22676 | The people are just individuals, and only present themselves as united to foreigners [Tocqueville] |
22679 | Vast empires are bad for well-being and freedom, though they may promote glory [Tocqueville] |
22680 | People would be much happier and freer in small nations [Tocqueville] |
22675 | In American judges rule according to the Constitution, not the law [Tocqueville] |
22677 | A monarchical family is always deeply concerned with the interests of the state [Tocqueville] |
22683 | Despots like to see their own regulations ignored, by themselves and their agents [Tocqueville] |
22669 | Aristocracy is constituted by inherited landed property [Tocqueville] |
22674 | In Europe it is thought that local government is best handled centrally [Tocqueville] |
22678 | An election, and its lead up time, are always a national crisis [Tocqueville] |
22682 | Universal suffrage is no guarantee of wise choices [Tocqueville] |
22670 | Slavery undermines the morals and energy of a society [Tocqueville] |
22681 | The liberty of the press is more valuable for what it prevents than what it promotes [Tocqueville] |
22672 | It is admirable to elevate the humble to the level of the great, but the opposite is depraved [Tocqueville] |
22671 | Equality can only be established by equal rights for all (or no rights for anyone) [Tocqueville] |
5993 | The ascending scale of living creatures requires a perfect being [Cleanthes, by Tieleman] |