83 ideas
15357 | Philosophy is the most general intellectual discipline [Horsten] |
17663 | If you know what it is, investigation is pointless. If you don't, investigation is impossible [Armstrong] |
15352 | A definition should allow the defined term to be eliminated [Horsten] |
15324 | Semantic theories of truth seek models; axiomatic (syntactic) theories seek logical principles [Horsten] |
15323 | Truth is a property, because the truth predicate has an extension [Horsten] |
15374 | Truth has no 'nature', but we should try to describe its behaviour in inferences [Horsten] |
15348 | Propositions have sentence-like structures, so it matters little which bears the truth [Horsten] |
15333 | Modern correspondence is said to be with the facts, not with true propositions [Horsten] |
15337 | The correspondence 'theory' is too vague - about both 'correspondence' and 'facts' [Horsten] |
15334 | The coherence theory allows multiple coherent wholes, which could contradict one another [Horsten] |
15336 | The pragmatic theory of truth is relative; useful for group A can be useless for group B [Horsten] |
15354 | Tarski's hierarchy lacks uniform truth, and depends on contingent factors [Horsten] |
15340 | Tarski Bi-conditional: if you'll assert φ you'll assert φ-is-true - and also vice versa [Horsten] |
15345 | Semantic theories have a regress problem in describing truth in the languages for the models [Horsten] |
15373 | Axiomatic approaches avoid limiting definitions to avoid the truth predicate, and limited sizes of models [Horsten] |
15346 | Axiomatic approaches to truth avoid the regress problem of semantic theories [Horsten] |
15371 | An axiomatic theory needs to be of maximal strength, while being natural and sound [Horsten] |
15332 | 'Reflexive' truth theories allow iterations (it is T that it is T that p) [Horsten] |
15361 | A good theory of truth must be compositional (as well as deriving biconditionals) [Horsten] |
15350 | The Naďve Theory takes the bi-conditionals as axioms, but it is inconsistent, and allows the Liar [Horsten] |
15351 | Axiomatic theories take truth as primitive, and propose some laws of truth as axioms [Horsten] |
15367 | By adding truth to Peano Arithmetic we increase its power, so truth has mathematical content! [Horsten] |
15330 | Friedman-Sheard theory keeps classical logic and aims for maximum strength [Horsten] |
15331 | Kripke-Feferman has truth gaps, instead of classical logic, and aims for maximum strength [Horsten] |
15325 | Inferential deflationism says truth has no essence because no unrestricted logic governs the concept [Horsten] |
15344 | Deflationism skips definitions and models, and offers just accounts of basic laws of truth [Horsten] |
15356 | Deflationism concerns the nature and role of truth, but not its laws [Horsten] |
15368 | This deflationary account says truth has a role in generality, and in inference [Horsten] |
15358 | Deflationism says truth isn't a topic on its own - it just concerns what is true [Horsten] |
15359 | Deflation: instead of asserting a sentence, we can treat it as an object with the truth-property [Horsten] |
15329 | Nonclassical may accept T/F but deny applicability, or it may deny just T or F as well [Horsten] |
15326 | Doubt is thrown on classical logic by the way it so easily produces the liar paradox [Horsten] |
15341 | Deduction Theorem: ψ only derivable from φ iff φ→ψ are axioms [Horsten] |
15328 | A theory is 'non-conservative' if it facilitates new mathematical proofs [Horsten] |
15349 | It is easier to imagine truth-value gaps (for the Liar, say) than for truth-value gluts (both T and F) [Horsten] |
15366 | Satisfaction is a primitive notion, and very liable to semantical paradoxes [Horsten] |
15353 | The first incompleteness theorem means that consistency does not entail soundness [Horsten] |
15355 | Strengthened Liar: 'this sentence is not true in any context' - in no context can this be evaluated [Horsten] |
15364 | English expressions are denumerably infinite, but reals are nondenumerable, so many are unnameable [Horsten] |
15360 | ZFC showed that the concept of set is mathematical, not logical, because of its existence claims [Horsten] |
15369 | Set theory is substantial over first-order arithmetic, because it enables new proofs [Horsten] |
15370 | Predicativism says mathematical definitions must not include the thing being defined [Horsten] |
17688 | Negative facts are supervenient on positive facts, suggesting they are positive facts [Armstrong] |
15338 | We may believe in atomic facts, but surely not complex disjunctive ones? [Horsten] |
15363 | In the supervaluationist account, disjunctions are not determined by their disjuncts [Horsten] |
15362 | If 'Italy is large' lacks truth, so must 'Italy is not large'; but classical logic says it's large or it isn't [Horsten] |
17691 | Nothing is genuinely related to itself [Armstrong] |
17679 | All instances of some property are strictly identical [Armstrong] |
12677 | Armstrong holds that all basic properties are categorical [Armstrong, by Ellis] |
17666 | Actualism means that ontology cannot contain what is merely physically possible [Armstrong] |
17667 | Dispositions exist, but their truth-makers are actual or categorical properties [Armstrong] |
17687 | If everything is powers there is a vicious regress, as powers are defined by more powers [Armstrong] |
17678 | Universals are just the repeatable features of a world [Armstrong] |
17669 | Realist regularity theories of laws need universals, to pick out the same phenomena [Armstrong] |
17677 | Past, present and future must be equally real if universals are instantiated [Armstrong] |
15442 | Universals are abstractions from their particular instances [Armstrong, by Lewis] |
17686 | Universals are abstractions from states of affairs [Armstrong] |
17668 | It is likely that particulars can be individuated by unique conjunctions of properties [Armstrong] |
17680 | The identity of a thing with itself can be ruled out as a pseudo-property [Armstrong] |
17693 | The necessary/contingent distinction may need to recognise possibilities as real [Armstrong] |
15372 | Some claim that indicative conditionals are believed by people, even though they are not actually held true [Horsten] |
17685 | Induction aims at 'all Fs', but abduction aims at hidden or theoretical entities [Armstrong] |
17683 | Science suggests that the predicate 'grue' is not a genuine single universal [Armstrong] |
17675 | Unlike 'green', the 'grue' predicate involves a time and a change [Armstrong] |
17674 | The raven paradox has three disjuncts, confirmed by confirming any one of them [Armstrong] |
17672 | A good reason for something (the smoke) is not an explanation of it (the fire) [Armstrong] |
17684 | To explain observations by a regular law is to explain the observations by the observations [Armstrong] |
17676 | Best explanations explain the most by means of the least [Armstrong] |
17664 | Each subject has an appropriate level of abstraction [Armstrong] |
15347 | A theory of syntax can be based on Peano arithmetic, thanks to the translation by Gödel coding [Horsten] |
1748 | Archelaus was the first person to say that the universe is boundless [Archelaus, by Diog. Laertius] |
17692 | We can't deduce the phenomena from the One [Armstrong] |
17689 | Absences might be effects, but surely not causes? [Armstrong] |
17682 | A universe couldn't consist of mere laws [Armstrong] |
17662 | Science depends on laws of nature to study unobserved times and spaces [Armstrong] |
17690 | Oaken conditional laws, Iron universal laws, and Steel necessary laws [Armstrong, by PG] |
17670 | Newton's First Law refers to bodies not acted upon by a force, but there may be no such body [Armstrong] |
8582 | Regularities are lawful if a second-order universal unites two first-order universals [Armstrong, by Lewis] |
17671 | A naive regularity view says if it never occurs then it is impossible [Armstrong] |
17681 | The laws of nature link properties with properties [Armstrong] |
16246 | Rather than take necessitation between universals as primitive, just make laws primitive [Maudlin on Armstrong] |
9480 | Armstrong has an unclear notion of contingent necessitation, which can't necessitate anything [Bird on Armstrong] |
5989 | Archelaus said life began in a primeval slime [Archelaus, by Schofield] |