32 ideas
17926 | Rejecting double negation elimination undermines reductio proofs [Colyvan] |
17925 | Showing a disproof is impossible is not a proof, so don't eliminate double negation [Colyvan] |
17924 | Excluded middle says P or not-P; bivalence says P is either true or false [Colyvan] |
17929 | Löwenheim proved his result for a first-order sentence, and Skolem generalised it [Colyvan] |
17930 | Axioms are 'categorical' if all of their models are isomorphic [Colyvan] |
17928 | Ordinal numbers represent order relations [Colyvan] |
17923 | Intuitionists only accept a few safe infinities [Colyvan] |
17941 | Infinitesimals were sometimes zero, and sometimes close to zero [Colyvan] |
17922 | Reducing real numbers to rationals suggested arithmetic as the foundation of maths [Colyvan] |
17936 | Transfinite induction moves from all cases, up to the limit ordinal [Colyvan] |
17940 | Most mathematical proofs are using set theory, but without saying so [Colyvan] |
17931 | Structuralism say only 'up to isomorphism' matters because that is all there is to it [Colyvan] |
17932 | If 'in re' structures relies on the world, does the world contain rich enough structures? [Colyvan] |
19284 | Asserting a necessity just expresses our inability to imagine it is false [Blackburn] |
14629 | If we are told the source of necessity, this seems to be a regress if the source is not already necessary [Blackburn] |
14529 | If something underlies a necessity, is that underlying thing necessary or contingent? [Blackburn, by Hale/Hoffmann,A] |
6451 | Visual sense data are an inner picture show which represents the world [Blackburn] |
2866 | A true belief might be based on a generally reliable process that failed on this occasion [Blackburn] |
17943 | Probability supports Bayesianism better as degrees of belief than as ratios of frequencies [Colyvan] |
17939 | Mathematics can reveal structural similarities in diverse systems [Colyvan] |
17938 | Mathematics can show why some surprising events have to occur [Colyvan] |
17934 | Proof by cases (by 'exhaustion') is said to be unexplanatory [Colyvan] |
17933 | Reductio proofs do not seem to be very explanatory [Colyvan] |
17935 | If inductive proofs hold because of the structure of natural numbers, they may explain theorems [Colyvan] |
17942 | Can a proof that no one understands (of the four-colour theorem) really be a proof? [Colyvan] |
17937 | Mathematical generalisation is by extending a system, or by abstracting away from it [Colyvan] |
23996 | Akrasia is intelligible in hindsight, when we revisit our previous emotions [Blackburn] |
11911 | Some philosophers always want more from morality; for others, nature is enough [Blackburn] |
7258 | The forefather of modern intuitionism is Richard Price [Price,R, by Dancy,J] |
2864 | The main objection to intuitionism in ethics is that intuition is a disguise for prejudice or emotion [Blackburn] |
2865 | Critics of prescriptivism observe that it is consistent to accept an ethical verdict but refuse to be bound by it [Blackburn] |
23223 | The word 'respect' ranges from mere non-interference to the highest levels of reverence [Blackburn] |