41 ideas
21752 | Prior to Gödel we thought truth in mathematics consisted in provability [Gödel, by Quine] |
17835 | Gödel show that the incompleteness of set theory was a necessity [Gödel, by Hallett,M] |
17886 | The limitations of axiomatisation were revealed by the incompleteness theorems [Gödel, by Koellner] |
10071 | Second Incompleteness: nice theories can't prove their own consistency [Gödel, by Smith,P] |
19123 | If soundness can't be proved internally, 'reflection principles' can be added to assert soundness [Gödel, by Halbach/Leigh] |
10621 | Gödel's First Theorem sabotages logicism, and the Second sabotages Hilbert's Programme [Smith,P on Gödel] |
17888 | The undecidable sentence can be decided at a 'higher' level in the system [Gödel] |
10132 | There can be no single consistent theory from which all mathematical truths can be derived [Gödel, by George/Velleman] |
3198 | Gödel showed that arithmetic is either incomplete or inconsistent [Gödel, by Rey] |
10072 | First Incompleteness: arithmetic must always be incomplete [Gödel, by Smith,P] |
9590 | Arithmetical truth cannot be fully and formally derived from axioms and inference rules [Gödel, by Nagel/Newman] |
11069 | Gödel's Second says that semantic consequence outruns provability [Gödel, by Hanna] |
10118 | First Incompleteness: a decent consistent system is syntactically incomplete [Gödel, by George/Velleman] |
10122 | Second Incompleteness: a decent consistent system can't prove its own consistency [Gödel, by George/Velleman] |
10611 | There is a sentence which a theory can show is true iff it is unprovable [Gödel, by Smith,P] |
10867 | 'This system can't prove this statement' makes it unprovable either way [Gödel, by Clegg] |
8747 | Realists are happy with impredicative definitions, which describe entities in terms of other existing entities [Gödel, by Shapiro] |
9476 | If dispositions are more fundamental than causes, then they won't conceptually reduce to them [Bird on Lewis] |
8425 | For true counterfactuals, both antecedent and consequent true is closest to actuality [Lewis] |
8424 | Determinism says there can't be two identical worlds up to a time, with identical laws, which then differ [Lewis] |
3192 | Basic logic can be done by syntax, with no semantics [Gödel, by Rey] |
8420 | A proposition is a set of possible worlds where it is true [Lewis] |
3546 | 'Phronesis' should translate as 'practical intelligence', not as prudence [Annas] |
3547 | Epicureans achieve pleasure through character development [Annas] |
3543 | Cyrenaics pursue pleasure, but don't equate it with happiness [Annas] |
3541 | Ancient ethics uses attractive notions, not imperatives [Annas] |
3550 | Principles cover life as a whole, where rules just cover actions [Annas] |
3551 | Virtue theory tries to explain our duties in terms of our character [Annas] |
3552 | If excessively good actions are admirable but not required, then duty isn't basic [Annas] |
3542 | We should do good when necessary, not maximise it [Annas] |
8405 | A theory of causation should explain why cause precedes effect, not take it for granted [Lewis, by Field,H] |
8427 | I reject making the direction of causation axiomatic, since that takes too much for granted [Lewis] |
10392 | It is just individious discrimination to pick out one cause and label it as 'the' cause [Lewis] |
8419 | The modern regularity view says a cause is a member of a minimal set of sufficient conditions [Lewis] |
8421 | Regularity analyses could make c an effect of e, or an epiphenomenon, or inefficacious, or pre-empted [Lewis] |
17525 | The counterfactual view says causes are necessary (rather than sufficient) for their effects [Lewis, by Bird] |
17524 | Lewis has basic causation, counterfactuals, and a general ancestral (thus handling pre-emption) [Lewis, by Bird] |
8397 | Counterfactual causation implies all laws are causal, which they aren't [Tooley on Lewis] |
8423 | My counterfactual analysis applies to particular cases, not generalisations [Lewis] |
8426 | One event causes another iff there is a causal chain from first to second [Lewis] |
4795 | Lewis's account of counterfactuals is fine if we know what a law of nature is, but it won't explain the latter [Cohen,LJ on Lewis] |