45 ideas
| 18986 | Truth is just a name for verification-processes [James] |
| 18983 | In many cases there is no obvious way in which ideas can agree with their object [James] |
| 18972 | Ideas are true in so far as they co-ordinate our experiences [James] |
| 18973 | New opinions count as 'true' if they are assimilated to an individual's current beliefs [James] |
| 18984 | True ideas are those we can assimilate, validate, corroborate and verify (and false otherwise) [James] |
| 13520 | A 'tautology' must include connectives [Wolf,RS] |
| 13524 | Deduction Theorem: T∪{P}|-Q, then T|-(P→Q), which justifies Conditional Proof [Wolf,RS] |
| 13521 | Universal Specification: ∀xP(x) implies P(t). True for all? Then true for an instance [Wolf,RS] |
| 13522 | Universal Generalization: If we prove P(x) with no special assumptions, we can conclude ∀xP(x) [Wolf,RS] |
| 13523 | Existential Generalization (or 'proof by example'): if we can say P(t), then we can say something is P [Wolf,RS] |
| 13529 | Empty Set: ∃x∀y ¬(y∈x). The unique empty set exists [Wolf,RS] |
| 13526 | Comprehension Axiom: if a collection is clearly specified, it is a set [Wolf,RS] |
| 13534 | In first-order logic syntactic and semantic consequence (|- and |=) nicely coincide [Wolf,RS] |
| 13535 | First-order logic is weakly complete (valid sentences are provable); we can't prove every sentence or its negation [Wolf,RS] |
| 13519 | Model theory uses sets to show that mathematical deduction fits mathematical truth [Wolf,RS] |
| 13531 | Model theory reveals the structures of mathematics [Wolf,RS] |
| 13532 | Model theory 'structures' have a 'universe', some 'relations', some 'functions', and some 'constants' [Wolf,RS] |
| 13533 | First-order model theory rests on completeness, compactness, and the Löwenheim-Skolem-Tarski theorem [Wolf,RS] |
| 13537 | An 'isomorphism' is a bijection that preserves all structural components [Wolf,RS] |
| 13539 | The LST Theorem is a serious limitation of first-order logic [Wolf,RS] |
| 13538 | If a theory is complete, only a more powerful language can strengthen it [Wolf,RS] |
| 13525 | Most deductive logic (unlike ordinary reasoning) is 'monotonic' - we don't retract after new givens [Wolf,RS] |
| 13530 | An ordinal is an equivalence class of well-orderings, or a transitive set whose members are transitive [Wolf,RS] |
| 13518 | Modern mathematics has unified all of its objects within set theory [Wolf,RS] |
| 18987 | A 'thing' is simply carved out of reality for human purposes [James] |
| 18981 | 'Substance' is just a word for groupings and structures in experience [James] |
| 22868 | The value and truth of knowledge are measured by success in activity [Dewey] |
| 18974 | Truth is a species of good, being whatever proves itself good in the way of belief [James] |
| 18989 | Pragmatism accepts any hypothesis which has useful consequences [James] |
| 18971 | Theories are practical tools for progress, not answers to enigmas [James] |
| 18982 | Pragmatism says all theories are instrumental - that is, mental modes of adaptation to reality [James] |
| 18985 | True thoughts are just valuable instruments of action [James] |
| 22865 | Habits constitute the self [Dewey] |
| 18975 | We return to experience with concepts, where they show us differences [James] |
| 22871 | The good people are those who improve; the bad are those who deteriorate [Dewey] |
| 22876 | Democracy is the development of human nature when it shares in the running of communal activities [Dewey] |
| 22875 | Democracy is not just a form of government; it is a mode of shared living [Dewey] |
| 22874 | Individuality is only developed within groups [Dewey] |
| 18980 | If there is a 'greatest knower', it doesn't follow that they know absolutely everything [James] |
| 18978 | It is hard to grasp a cosmic mind which produces such a mixture of goods and evils [James] |
| 18991 | If the God hypothesis works well, then it is true [James] |
| 18977 | The wonderful design of a woodpecker looks diabolical to its victims [James] |
| 18979 | Things with parts always have some structure, so they always appear to be designed [James] |
| 18976 | Private experience is the main evidence for God [James] |
| 18990 | Nirvana means safety from sense experience, and hindus and buddhists are just afraid of life [James] |