36 ideas
13252 | Some truths have true negations [Beall/Restall] |
13247 | A truthmaker is an object which entails a sentence [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] |
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] |
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13234 | The view of logic as knowing a body of truths looks out-of-date [Beall/Restall] |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] |
13240 | A sentence follows from others if they always model it [Beall/Restall] |
9148 | I think of variables as objects rather than as signs [Fine,K] |
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] |
14775 | Numbers are just names devised for counting [Peirce] |
14776 | That two two-eyed people must have four eyes is a statement about numbers, not a fact [Peirce] |
13244 | Relevant necessity is always true for some situation (not all situations) [Beall/Restall] |
14770 | Reasoning is based on statistical induction, so it can't achieve certainty or precision [Peirce] |
14774 | Innate truths are very uncertain and full of error, so they certainly have exceptions [Peirce] |
14772 | If we decide an idea is inspired, we still can't be sure we have got the idea right [Peirce] |
14773 | A truth is hard for us to understand if it rests on nothing but inspiration [Peirce] |
14771 | Only reason can establish whether some deliverance of revelation really is inspired [Peirce] |
14769 | Only imagination can connect phenomena together in a rational way [Peirce] |
9152 | If green is abstracted from a thing, it is only seen as a type if it is common to many things [Fine,K] |
13239 | Judgement is always predicating a property of a subject [Beall/Restall] |
9149 | To obtain the number 2 by abstraction, we only want to abstract the distinctness of a pair of objects [Fine,K] |
9150 | We should define abstraction in general, with number abstraction taken as a special case [Fine,K] |
9146 | After abstraction all numbers seem identical, so only 0 and 1 will exist! [Fine,K] |
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] |