53 ideas
21752 | Prior to Gödel we thought truth in mathematics consisted in provability [Gödel, by Quine] |
9449 | The plausible Barcan formula implies modality in the actual world [Bird] |
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] |
17888 | The undecidable sentence can be decided at a 'higher' level in the system [Gödel] |
10621 | Gödel's First Theorem sabotages logicism, and the Second sabotages Hilbert's Programme [Smith,P on Gödel] |
10132 | There can be no single consistent theory from which all mathematical truths can be derived [Gödel, by George/Velleman] |
10072 | First Incompleteness: arithmetic must always be incomplete [Gödel, by Smith,P] |
3198 | Gödel showed that arithmetic is either incomplete or inconsistent [Gödel, by Rey] |
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] |
9501 | If all existents are causally active, that excludes abstracta and causally isolated objects [Bird] |
9500 | If naturalism refers to supervenience, that leaves necessary entities untouched [Bird] |
9502 | There might be just one fundamental natural property [Bird] |
9477 | Categorical properties are not modally fixed, but change across possible worlds [Bird] |
9490 | The categoricalist idea is that a property is only individuated by being itself [Bird] |
9495 | If we abstractly define a property, that doesn't mean some object could possess it [Bird] |
9492 | Categoricalists take properties to be quiddities, with no essential difference between them [Bird] |
9503 | To name an abundant property is either a Fregean concept, or a simple predicate [Bird] |
14540 | Only real powers are fundamental [Bird, by Mumford/Anjum] |
9450 | If all properties are potencies, and stimuli and manifestation characterise them, there is a regress [Bird] |
9498 | The essence of a potency involves relations, e.g. mass, to impressed force and acceleration [Bird] |
9474 | A disposition is finkish if a time delay might mean the manifestation fizzles out [Bird] |
9475 | A robust pot attached to a sensitive bomb is not fragile, but if struck it will easily break [Bird] |
9499 | Megarian actualists deny unmanifested dispositions [Bird] |
9486 | Why should a universal's existence depend on instantiation in an existing particular? [Bird] |
9472 | Resemblance itself needs explanation, presumably in terms of something held in common [Bird] |
9482 | If the laws necessarily imply p, that doesn't give a new 'nomological' necessity [Bird] |
9481 | Logical necessitation is not a kind of necessity; George Orwell not being Eric Blair is not a real possibility [Bird] |
9505 | Empiricist saw imaginability and possibility as close, but now they seem remote [Bird] |
9491 | Haecceitism says identity is independent of qualities and without essence [Bird] |
9487 | We can't reject all explanations because of a regress; inexplicable A can still explain B [Bird] |
3192 | Basic logic can be done by syntax, with no semantics [Gödel, by Rey] |
9493 | We should explain causation by powers, not powers by causation [Bird] |
9494 | Singularism about causes is wrong, as the universals involved imply laws [Bird] |
9507 | Laws are explanatory relationships of things, which supervene on their essences [Bird] |
9488 | Laws are either disposition regularities, or relations between properties [Bird] |
9496 | That other diamonds are hard does not explain why this one is [Bird] |
9479 | Dispositional essentialism says laws (and laws about laws) are guaranteed regularities [Bird] |
9473 | Laws cannot offer unified explanations if they don't involve universals [Bird] |
9484 | If the universals for laws must be instantiated, a vanishing particular could destroy a law [Bird] |
9506 | Salt necessarily dissolves in water, because of the law which makes the existence of salt possible [Bird] |
23713 | Most laws supervene on fundamental laws, which are explained by basic powers [Bird, by Friend/Kimpton-Nye] |
9489 | Essentialism can't use conditionals to explain regularities, because of possible interventions [Bird] |
5470 | The idea of laws of nature arose in the Middle Ages [Hall,AR, by Ellis] |
9504 | The relational view of space-time doesn't cover times and places where things could be [Bird] |