102 ideas
15357 | Philosophy is the most general intellectual discipline [Horsten] |
24047 | An account is either a definition or a demonstration [Aristotle] |
24052 | From one thing alone we can infer its contrary [Aristotle] |
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 Naïve 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] |
1729 | We perceive number by the denial of continuity [Aristotle] |
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] |
24057 | What is prior is always potentially present in what is next in order [Aristotle] |
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] |
16752 | Sight is the essence of the eye, fitting its definition; the eye itself is just the matter [Aristotle] |
24058 | The substance is the cause of a thing's being [Aristotle] |
24055 | Matter is potential, form is actual [Aristotle] |
24040 | Scientists explain anger by the matter, dialecticians by the form and the account [Aristotle] |
14895 | 'Superficial' contingency: false in some world; 'Deep' contingency: no obvious verification [Evans, by Macià/Garcia-Carpentiro] |
11881 | Rigid designators can be meaningful even if empty [Evans, by Mackie,P] |
15372 | Some claim that indicative conditionals are believed by people, even though they are not actually held true [Horsten] |
5051 | The intellect has potential to think, like a tablet on which nothing has yet been written [Aristotle] |
16723 | Perception of sensible objects is virtually never wrong [Aristotle] |
1724 | Perception necessitates pleasure and pain, which necessitates appetite [Aristotle] |
1730 | Why do we have many senses, and not just one? [Aristotle] |
17711 | Our minds take on the form of what is being perceived [Aristotle, by Mares] |
1725 | Why can't we sense the senses? And why do senses need stimuli? [Aristotle] |
1732 | Sense organs aren't the end of sensation, or they would know what does the sensing [Aristotle] |
1728 | Many objects of sensation are common to all the senses [Aristotle] |
1727 | Some objects of sensation are unique to one sense, where deception is impossible [Aristotle] |
1734 | In moral thought images are essential, to be pursued or avoided [Aristotle] |
1726 | We may think when we wish, but not perceive, because universals are within the mind [Aristotle] |
16647 | Demonstration starts from a definition of essence, so we can derive (or conjecture about) the properties [Aristotle] |
24048 | Demonstrations move from starting-points to deduced conclusions [Aristotle] |
16646 | To understand a triangle summing to two right angles, we need to know the essence of a line [Aristotle] |
1714 | Mind involves movement, perception, incorporeality [Aristotle] |
5507 | Aristotle led to the view that there are several souls, all somewhat physical [Aristotle, by Martin/Barresi] |
24051 | Soul is seen as what moves, or what is least physical, or a combination of elements [Aristotle] |
12086 | Psuché is the form and actuality of a body which potentially has life [Aristotle] |
16754 | The soul is the cause or source of movement, the essence of body, and its end [Aristotle] |
24046 | Understanding is impossible, if it involves the understanding having parts [Aristotle] |
1717 | If the soul is composed of many physical parts, it can't be a true unity [Aristotle] |
24053 | If a soul have parts, what unites them? [Aristotle] |
1721 | What unifies the soul would have to be a super-soul, which seems absurd [Aristotle] |
1735 | In a way the soul is everything which exists, through its perceptions and thoughts [Aristotle] |
24061 | If we divide the mind up according to its capacities, there are a lot of them [Aristotle] |
24062 | Self-moving animals must have desires, and that entails having imagination [Aristotle] |
1710 | Emotion involves the body, thinking uses the mind, imagination hovers between them [Aristotle] |
24056 | The soul (or parts of it) is not separable from the body [Aristotle] |
24039 | All the emotions seem to involve the body, simultaneously with the feeling [Aristotle] |
24050 | If soul is separate from body, why does it die when the body dies? [Aristotle] |
24049 | Thinkers place the soul within the body, but never explain how they are attached [Aristotle] |
1514 | Early thinkers concentrate on the soul but ignore the body, as if it didn't matter what body received the soul [Aristotle] |
2683 | Aristotle has a problem fitting his separate reason into the soul, which is said to be the form of the body [Ackrill on Aristotle] |
1718 | Does the mind think or pity, or does the whole man do these things? [Aristotle] |
13275 | The soul and the body are inseparable, like the imprint in some wax [Aristotle] |
1733 | Thinking is not perceiving, but takes the form of imagination and speculation [Aristotle] |
23307 | Aristotle makes belief a part of reason, but sees desires as separate [Aristotle, by Sorabji] |
15347 | A theory of syntax can be based on Peano arithmetic, thanks to the translation by Gödel coding [Horsten] |
24060 | Self-controlled follow understanding, when it is opposed to desires [Aristotle] |
4376 | Pleasure and pain are perceptions of things as good or bad [Aristotle] |
1740 | Nature does nothing in vain [Aristotle] |
1739 | If all movement is either pushing or pulling, there must be a still point in between where it all starts [Aristotle] |
24045 | Movement is spatial, alteration, withering or growth [Aristotle] |
1738 | Practical reason is based on desire, so desire must be the ultimate producer of movement [Aristotle] |
24044 | Movement can be intrinsic (like a ship) or relative (like its sailors) [Aristotle] |
24064 | If something is pushed, it pushes back [Aristotle] |
24063 | What is born has growth, a prime, and a withering away [Aristotle] |