87 ideas
| 15357 | Philosophy is the most general intellectual discipline [Horsten] |
| 15352 | A definition should allow the defined term to be eliminated [Horsten] |
| 10882 | Predicative definitions only refer to entities outside the defined collection [Horsten] |
| 23000 | Vicious regresses force you to another level; non-vicious imply another level [Baron/Miller] |
| 15323 | Truth is a property, because the truth predicate has an extension [Horsten] |
| 15324 | Semantic theories of truth seek models; axiomatic (syntactic) theories seek logical principles [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] |
| 15332 | 'Reflexive' truth theories allow iterations (it is T that it is T that p) [Horsten] |
| 15346 | Axiomatic approaches to truth avoid the regress problem of semantic theories [Horsten] |
| 15361 | A good theory of truth must be compositional (as well as deriving biconditionals) [Horsten] |
| 15371 | An axiomatic theory needs to be of maximal strength, while being natural and sound [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] |
| 15373 | Axiomatic approaches avoid limiting definitions to avoid the truth predicate, and limited sizes of models [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] |
| 15356 | Deflationism concerns the nature and role of truth, but not its laws [Horsten] |
| 15344 | Deflationism skips definitions and models, and offers just accounts of basic laws of truth [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] |
| 10884 | A theory is 'categorical' if it has just one model up to isomorphism [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] |
| 23024 | A traveller takes a copy of a picture into the past, gives it the artist, who then creates the original! [Baron/Miller] |
| 15364 | English expressions are denumerably infinite, but reals are nondenumerable, so many are unnameable [Horsten] |
| 10885 | Computer proofs don't provide explanations [Horsten] |
| 10881 | The concept of 'ordinal number' is set-theoretic, not arithmetical [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] |
| 23008 | Grounding is intended as a relation that fits dependences between things [Baron/Miller] |
| 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] |
| 23018 | How does a changing object retain identity or have incompatible properties over time? [Baron/Miller] |
| 15372 | Some claim that indicative conditionals are believed by people, even though they are not actually held true [Horsten] |
| 3061 | Anaxarchus said that he was not even sure that he knew nothing [Anaxarchus, by Diog. Laertius] |
| 15347 | A theory of syntax can be based on Peano arithmetic, thanks to the translation by Gödel coding [Horsten] |
| 23011 | Modern accounts of causation involve either processes or counterfactuals [Baron/Miller] |
| 23013 | The main process theory of causation says it is transference of mass, energy, momentum or charge [Baron/Miller] |
| 23014 | If causes are processes, what is causation by omission? (Distinguish legal from scientific causes?) [Baron/Miller] |
| 23015 | The counterfactual theory of causation handles the problem no matter what causes actually are [Baron/Miller] |
| 23016 | Counterfactual theories struggle with pre-emption by a causal back-up system [Baron/Miller] |
| 23009 | There is no second 'law' of thermodynamics; it just reflects probabilities of certain microstates [Baron/Miller] |
| 23002 | In relativity space and time depend on one's motion, but spacetime gives an invariant metric [Baron/Miller] |
| 22988 | The block universe theory says entities of all times exist, and time is the B-series [Baron/Miller] |
| 22991 | How can we know this is the present moment, if other times are real? [Baron/Miller] |
| 22992 | If we are actually in the past then we shouldn't experience time passing [Baron/Miller] |
| 22994 | Erzatz Presentism allows the existence of other times, with only the present 'actualised' [Baron/Miller] |
| 22998 | How do presentists explain relations between things existing at different times? [Baron/Miller] |
| 23017 | Presentism needs endurantism, because other theories imply most of the object doesn't exist [Baron/Miller] |
| 23023 | How can presentists move to the next future moment, if that doesn't exist? [Baron/Miller] |
| 22995 | Most of the sciences depend on the concept of time [Baron/Miller] |
| 22993 | For abstractionists past times might still exist, althought their objects don't [Baron/Miller] |
| 23001 | The error theory of time's passage says it is either a misdescription or a false inference [Baron/Miller] |
| 22999 | It is meaningless to measure the rate of time using time itself, and without a rate there is no flow [Baron/Miller] |
| 22986 | The C-series rejects A and B, and just sees times as order by betweenness, without direction [Baron/Miller] |
| 22996 | The A-series has to treat being past, present or future as properties [Baron/Miller] |
| 23007 | The B-series can have a direction, as long as it does not arise from temporal flow [Baron/Miller] |
| 23003 | Static theories cannot account for time's obvious asymmetry, so time must be dynamic [Baron/Miller] |
| 23004 | The direction of time is either primitive, or reducible to something else [Baron/Miller] |
| 23005 | The kaon does not seem to be time-reversal invariant, unlike the rest of nature [Baron/Miller] |
| 23006 | Maybe the past is just the direction of decreasing entropy [Baron/Miller] |
| 23010 | We could explain time's direction by causation: past is the direction of causes, future of effects [Baron/Miller] |
| 22989 | Static time theory presents change as one property at t1, and a different property at t2 [Baron/Miller] |
| 23020 | If a time traveller kills his youthful grandfather, he both exists and fails to exist [Baron/Miller] |
| 23022 | Presentism means there no existing past for a time traveller to visit [Baron/Miller] |
| 22987 | The past (unlike the future) is fixed, along with truths about it, by the existence of past objects [Baron/Miller] |
| 22990 | The moving spotlight says entities can have properties of being present, past or future [Baron/Miller] |
| 22997 | The present moment is a matter of existence, not of acquiring a property [Baron/Miller] |