46 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] |
16588 | I prefer a lack of form to mean non-existence, than to think of some quasi-existence [Augustine] |
22979 | Three main questions seem to be whether a thing is, what it is, and what sort it is [Augustine] |
22977 | I can distinguish different smells even when I am not experiencing them [Augustine] |
22982 | Why does joy in my mind make me happy, but joy in my memory doesn't? [Augustine] |
22981 | Mind and memory are the same, as shown in 'bear it in mind' or 'it slipped from mind' [Augustine] |
22980 | Memory contains innumerable principles of maths, as well as past sense experiences [Augustine] |
22983 | We would avoid remembering sorrow or fear if that triggered the emotions afresh [Augustine] |
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] |
22978 | Memory is so vast that I cannot recognise it as part of my mind [Augustine] |
17937 | Mathematical generalisation is by extending a system, or by abstracting away from it [Colyvan] |
22984 | Without memory I could not even speak of myself [Augustine] |
5982 | If the future does not exist, how can prophets see it? [Augustine] |
22976 | Memories are preserved separately, according to category [Augustine] |
7777 | We accept a metaphor when we see the sentence is false [Davidson] |
7775 | Understanding a metaphor is a creative act, with no rules [Davidson] |
7776 | Metaphors just mean what their words literally mean [Davidson] |
22985 | Everyone wants happiness [Augustine] |
5984 | Maybe time is an extension of the mind [Augustine] |
22888 | To be aware of time it can only exist in the mind, as memory or anticipation [Augustine, by Bardon] |
5980 | How can ten days ahead be a short time, if it doesn't exist? [Augustine] |
5979 | If the past is no longer, and the future is not yet, how can they exist? [Augustine] |
5981 | The whole of the current year is not present, so how can it exist? [Augustine] |
5978 | I know what time is, until someone asks me to explain it [Augustine] |
5983 | I disagree with the idea that time is nothing but cosmic movement [Augustine] |
5977 | Heaven and earth must be created, because they are subject to change [Augustine] |
22887 | If God existed before creation, why would a perfect being desire to change things? [Augustine, by Bardon] |
5976 | If God is outside time in eternity, can He hear prayers? [Augustine] |