36 ideas
17925 | Showing a disproof is impossible is not a proof, so don't eliminate double negation [Colyvan] |
17926 | Rejecting double negation elimination undermines reductio proofs [Colyvan] |
17924 | Excluded middle says P or not-P; bivalence says P is either true or false [Colyvan] |
8525 | Relations need terms, so they must be second-order entities based on first-order tropes [Campbell,K] |
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] |
8518 | Events are trope-sequences, in which tropes replace one another [Campbell,K] |
8513 | Two red cloths are separate instances of redness, because you can dye one of them blue [Campbell,K] |
8514 | Red could only recur in a variety of objects if it was many, which makes them particulars [Campbell,K] |
8522 | Tropes solve the Companionship Difficulty, since the resemblance is only between abstract particulars [Campbell,K] |
8523 | Tropes solve the Imperfect Community problem, as they can only resemble in one respect [Campbell,K] |
8524 | Trope theory makes space central to reality, as tropes must have a shape and size [Campbell,K] |
8521 | Nominalism has the problem that without humans nothing would resemble anything else [Campbell,K] |
8515 | Tropes are basic particulars, so concrete particulars are collections of co-located tropes [Campbell,K] |
8519 | Bundles must be unique, so the Identity of Indiscernibles is a necessity - which it isn't! [Campbell,K] |
4033 | Two pure spheres in non-absolute space are identical but indiscernible [Campbell,K] |
3061 | Anaxarchus said that he was not even sure that he knew nothing [Anaxarchus, by Diog. Laertius] |
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] |
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] |
17934 | Proof by cases (by 'exhaustion') is said to be unexplanatory [Colyvan] |
17937 | Mathematical generalisation is by extending a system, or by abstracting away from it [Colyvan] |
8512 | Abstractions come before the mind by concentrating on a part of what is presented [Campbell,K] |
8517 | Causal conditions are particular abstract instances of properties, which makes them tropes [Campbell,K] |
8516 | Davidson can't explain causation entirely by events, because conditions are also involved [Campbell,K] |