25 ideas
8729 | Intuitionists deny excluded middle, because it is committed to transcendent truth or objects [Shapiro] |
14352 | '¬', '&', and 'v' are truth functions: the truth of the compound is fixed by the truth of the components [Jackson] |
8763 | The number 3 is presumably identical as a natural, an integer, a rational, a real, and complex [Shapiro] |
18249 | Cauchy gave a formal definition of a converging sequence. [Shapiro] |
8764 | Categories are the best foundation for mathematics [Shapiro] |
8762 | Two definitions of 3 in terms of sets disagree over whether 1 is a member of 3 [Shapiro] |
8760 | Numbers do not exist independently; the essence of a number is its relations to other numbers [Shapiro] |
8761 | A 'system' is related objects; a 'pattern' or 'structure' abstracts the pure relations from them [Shapiro] |
8744 | Logicism seems to be a non-starter if (as is widely held) logic has no ontology of its own [Shapiro] |
8749 | Term Formalism says mathematics is just about symbols - but real numbers have no names [Shapiro] |
8750 | Game Formalism is just a matter of rules, like chess - but then why is it useful in science? [Shapiro] |
8752 | Deductivism says mathematics is logical consequences of uninterpreted axioms [Shapiro] |
8753 | Critics resent the way intuitionism cripples mathematics, but it allows new important distinctions [Shapiro] |
8731 | Conceptualist are just realists or idealist or nominalists, depending on their view of concepts [Shapiro] |
8730 | 'Impredicative' definitions refer to the thing being described [Shapiro] |
14360 | Possible worlds for subjunctives (and dispositions), and no-truth for indicatives? [Jackson] |
14353 | Modus ponens requires that A→B is F when A is T and B is F [Jackson] |
14354 | When A and B have the same truth value, A→B is true, because A→A is a logical truth [Jackson] |
14355 | (A&B)→A is a logical truth, even if antecedent false and consequent true, so it is T if A is F and B is T [Jackson] |
14358 | In the possible worlds account of conditionals, modus ponens and modus tollens are validated [Jackson] |
14359 | Only assertions have truth-values, and conditionals are not proper assertions [Jackson] |
14357 | Possible worlds account, unlike A⊃B, says nothing about when A is false [Jackson] |
14356 | We can't insist that A is relevant to B, as conditionals can express lack of relevance [Jackson] |
8725 | Rationalism tries to apply mathematical methodology to all of knowledge [Shapiro] |
13440 | Causation is the power of one property to produce another, and this gives time its direction [Esfeld] |