37 ideas
| 3859 | We do not wish merely to predict, we also want to explain [Newton-Smith] |
| 3870 | The real problem of science is how to choose between possible explanations [Newton-Smith] |
| 3853 | For science to be rational, we must explain scientific change rationally [Newton-Smith] |
| 3854 | Positivists hold that theoretical terms change, but observation terms don't [Newton-Smith] |
| 3855 | Critics attack positivist division between theory and observation [Newton-Smith] |
| 3861 | Theories generate infinite truths and falsehoods, so they cannot be used to assess probability [Newton-Smith] |
| 3869 | More truthful theories have greater predictive power [Newton-Smith] |
| 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] |
| 3867 | De re necessity arises from the way the world is [Newton-Smith] |
| 3872 | We must assess the truth of beliefs in identifying them [Newton-Smith] |
| 3857 | Defeat relativism by emphasising truth and reference, not meaning [Newton-Smith] |
| 3858 | A full understanding of 'yellow' involves some theory [Newton-Smith] |
| 3862 | All theories contain anomalies, and so are falsified! [Newton-Smith] |
| 3863 | The anomaly of Uranus didn't destroy Newton's mechanics - it led to Neptune's discovery [Newton-Smith] |
| 3864 | Anomalies are judged against rival theories, and support for the current theory [Newton-Smith] |
| 3865 | Why should it matter whether or not a theory is scientific? [Newton-Smith] |
| 3866 | If theories are really incommensurable, we could believe them all [Newton-Smith] |
| 3871 | Explaining an action is showing that it is rational [Newton-Smith] |
| 6005 | Animals are dangerous and nourishing, and can't form contracts of justice [Hermarchus, by Sedley] |