79 ideas
13395 | If an analysis shows the features of a concept, it doesn't seem to 'reduce' the concept [Jubien] |
16325 | Analysis rests on natural language, but its ideal is a framework which revises language [Halbach] |
16292 | An explicit definition enables the elimination of what is defined [Halbach] |
16307 | Don't trust analogies; they are no more than a guideline [Halbach] |
16330 | Truth-value 'gluts' allow two truth values together; 'gaps' give a partial conception of truth [Halbach] |
16339 | Truth axioms prove objects exist, so truth doesn't seem to be a logical notion [Halbach] |
16324 | Any definition of truth requires a metalanguage [Halbach] |
16293 | Traditional definitions of truth often make it more obscure, rather than less [Halbach] |
16301 | If people have big doubts about truth, a definition might give it more credibility [Halbach] |
16297 | Semantic theories avoid Tarski's Theorem by sticking to a sublanguage [Halbach] |
16337 | Disquotational truth theories are short of deductive power [Halbach] |
16322 | CT proves PA consistent, which PA can't do on its own, so CT is not conservative over PA [Halbach] |
16294 | Axiomatic truth doesn't presuppose a truth-definition, though it could admit it at a later stage [Halbach] |
16326 | The main semantic theories of truth are Kripke's theory, and revisions semantics [Halbach] |
16311 | To axiomatise Tarski's truth definition, we need a binary predicate for his 'satisfaction' [Halbach] |
16318 | Compositional Truth CT has the truth of a sentence depending of the semantic values of its constituents [Halbach] |
16299 | Gödel numbering means a theory of truth can use Peano Arithmetic as its base theory [Halbach] |
16340 | Truth axioms need a base theory, because that is where truth issues arise [Halbach] |
16305 | We know a complete axiomatisation of truth is not feasible [Halbach] |
16313 | A theory is 'conservative' if it adds no new theorems to its base theory [Halbach, by PG] |
16315 | The Tarski Biconditional theory TB is Peano Arithmetic, plus truth, plus all Tarski bi-conditionals [Halbach] |
16314 | Theories of truth are 'typed' (truth can't apply to sentences containing 'true'), or 'type-free' [Halbach] |
16327 | Friedman-Sheard is type-free Compositional Truth, with two inference rules for truth [Halbach] |
16329 | Kripke-Feferman theory KF axiomatises Kripke fixed-points, with Strong Kleene logic with gluts [Halbach] |
16332 | The KF theory is useful, but it is not a theory containing its own truth predicate [Halbach] |
16331 | The KF is much stronger deductively than FS, which relies on classical truth [Halbach] |
16319 | Compositional Truth CT proves generalisations, so is preferred in discussions of deflationism [Halbach] |
16320 | Some say deflationism is axioms which are conservative over the base theory [Halbach] |
16338 | Deflationism says truth is a disquotation device to express generalisations, adding no new knowledge [Halbach] |
16317 | The main problem for deflationists is they can express generalisations, but not prove them [Halbach] |
16316 | Deflationists say truth is just for expressing infinite conjunctions or generalisations [Halbach] |
16335 | In Strong Kleene logic a disjunction just needs one disjunct to be true [Halbach] |
16334 | In Weak Kleene logic there are 'gaps', neither true nor false if one component lacks a truth value [Halbach] |
16309 | Every attempt at formal rigour uses some set theory [Halbach] |
13378 | It is a mistake to think that the logic developed for mathematics can clarify language and philosophy [Jubien] |
16333 | The underestimated costs of giving up classical logic are found in mathematical reasoning [Halbach] |
16310 | A theory is some formulae and all of their consequences [Halbach] |
13402 | We only grasp a name if we know whether to apply it when the bearer changes [Jubien] |
13405 | The baptiser picks the bearer of a name, but social use decides the category [Jubien] |
13399 | Examples show that ordinary proper names are not rigid designators [Jubien] |
13398 | We could make a contingent description into a rigid and necessary one by adding 'actual' to it [Jubien] |
13392 | Philosophers reduce complex English kind-quantifiers to the simplistic first-order quantifier [Jubien] |
16342 | You cannot just say all of Peano arithmetic is true, as 'true' isn't part of the system [Halbach] |
16341 | Normally we only endorse a theory if we believe it to be sound [Halbach] |
16344 | Soundness must involve truth; the soundness of PA certainly needs it [Halbach] |
16347 | Many new paradoxes may await us when we study interactions between frameworks [Halbach] |
16336 | The liar paradox applies truth to a negated truth (but the conditional will serve equally) [Halbach] |
16321 | The compactness theorem can prove nonstandard models of PA [Halbach] |
16343 | The global reflection principle seems to express the soundness of Peano Arithmetic [Halbach] |
16312 | To reduce PA to ZF, we represent the non-negative integers with von Neumann ordinals [Halbach] |
16308 | Set theory was liberated early from types, and recent truth-theories are exploring type-free [Halbach] |
13404 | To exist necessarily is to have an essence whose own essence must be instantiated [Jubien] |
16345 | That Peano arithmetic is interpretable in ZF set theory is taken by philosophers as a reduction [Halbach] |
13386 | If objects are just conventional, there is no ontological distinction between stuff and things [Jubien] |
13403 | The category of Venus is not 'object', or even 'planet', but a particular class of good-sized object [Jubien] |
8499 | Nominalists cannot translate 'red resembles pink more than blue' into particulars [Jackson] |
8500 | Colour resemblance isn't just resemblance between things; 'colour' must be mentioned [Jackson] |
13375 | The idea that every entity must have identity conditions is an unfortunate misunderstanding [Jubien] |
13393 | Any entity has the unique property of being that specific entity [Jubien] |
13388 | It is incoherent to think that a given entity depends on its kind for its existence [Jubien] |
13384 | Objects need conventions for their matter, their temporal possibility, and their spatial possibility [Jubien] |
13385 | Basically, the world doesn't have ready-made 'objects'; we carve objects any way we like [Jubien] |
13383 | If the statue is loved and the clay hated, that is about the object first qua statue, then qua clay [Jubien] |
13400 | If one entity is an object, a statue, and some clay, these come apart in at least three ways [Jubien] |
13401 | The idea of coincident objects is a last resort, as it is opposed to commonsense naturalism [Jubien] |
13380 | Parts seem to matter when it is just an object, but not matter when it is a kind of object [Jubien] |
13376 | We should not regard essentialism as just nontrivial de re necessity [Jubien] |
13381 | Thinking of them as 'ships' the repaired ship is the original, but as 'objects' the reassembly is the original [Jubien] |
13382 | Rearranging the planks as a ship is confusing; we'd say it was the same 'object' with a different arrangement [Jubien] |
13379 | If two objects are indiscernible across spacetime, how could we decide whether or not they are the same? [Jubien] |
16346 | Maybe necessity is a predicate, not the usual operator, to make it more like truth [Halbach] |
13394 | Entailment does not result from mutual necessity; mutual necessity ensures entailment [Jubien] |
13391 | Modality concerns relations among platonic properties [Jubien] |
13374 | To analyse modality, we must give accounts of objects, properties and relations [Jubien] |
13389 | The love of possible worlds is part of the dream that technical logic solves philosophical problems [Jubien] |
13390 | Possible worlds don't explain necessity, because they are a bunch of parallel contingencies [Jubien] |
13396 | Analysing mental concepts points to 'inclusionism' - that mental phenomena are part of the physical [Jubien] |
13377 | First-order logic tilts in favour of the direct reference theory, in its use of constants for objects [Jubien] |
16298 | We need propositions to ascribe the same beliefs to people with different languages [Halbach] |