133 ideas
| 2546 | Philosophy is a magnificent failure in its attempt to overstep the limits of our knowledge [McGinn] |
| 16325 | Analysis rests on natural language, but its ideal is a framework which revises language [Halbach] |
| 6052 | Definitions identify two concepts, so they presuppose identity [McGinn] |
| 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] |
| 6064 | Regresses are only vicious in the context of an explanation [McGinn] |
| 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] |
| 15647 | Truth definitions don't produce a good theory, because they go beyond your current language [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] |
| 6088 | Truth is a method of deducing facts from propositions [McGinn] |
| 6084 | 'Snow does not fall' corresponds to snow does fall [McGinn] |
| 6085 | The idea of truth is built into the idea of correspondence [McGinn] |
| 6083 | The coherence theory of truth implies idealism, because facts are just coherent beliefs [McGinn] |
| 15649 | In semantic theories of truth, the predicate is in an object-language, and the definition in a metalanguage [Halbach] |
| 16297 | Semantic theories avoid Tarski's Theorem by sticking to a sublanguage [Halbach] |
| 16337 | Disquotational truth theories are short of deductive power [Halbach] |
| 15650 | Axiomatic theories of truth need a weak logical framework, and not a strong metatheory [Halbach] |
| 16322 | CT proves PA consistent, which PA can't do on its own, so CT is not conservative over PA [Halbach] |
| 15648 | Instead of a truth definition, add a primitive truth predicate, and axioms for how it works [Halbach] |
| 15654 | If truth is defined it can be eliminated, whereas axiomatic truth has various commitments [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] |
| 15655 | Should axiomatic truth be 'conservative' - not proving anything apart from implications of the axioms? [Halbach] |
| 16327 | Friedman-Sheard is type-free Compositional Truth, with two inference rules for truth [Halbach] |
| 16331 | The KF is much stronger deductively than FS, which relies on classical truth [Halbach] |
| 16332 | The KF theory is useful, but it is not a theory containing its own truth predicate [Halbach] |
| 16329 | Kripke-Feferman theory KF axiomatises Kripke fixed-points, with Strong Kleene logic with gluts [Halbach] |
| 16320 | Some say deflationism is axioms which are conservative over the base theory [Halbach] |
| 15656 | Deflationists say truth merely serves to express infinite conjunctions [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] |
| 16319 | Compositional Truth CT proves generalisations, so is preferred in discussions of deflationism [Halbach] |
| 6087 | Without the disquotation device for truth, you could never form beliefs from others' testimony [McGinn] |
| 6086 | Truth is the property of propositions that makes it possible to deduce facts [McGinn] |
| 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] |
| 15657 | To prove the consistency of set theory, we must go beyond set theory [Halbach] |
| 16309 | Every attempt at formal rigour uses some set theory [Halbach] |
| 16333 | The underestimated costs of giving up classical logic are found in mathematical reasoning [Halbach] |
| 15652 | We can use truth instead of ontologically loaded second-order comprehension assumptions about properties [Halbach] |
| 6051 | In 'x is F and x is G' we must assume the identity of x in the two statements [McGinn] |
| 6055 | Both non-contradiction and excluded middle need identity in their formulation [McGinn] |
| 6059 | Identity is unitary, indefinable, fundamental and a genuine relation [McGinn] |
| 2544 | Thoughts have a dual aspect: as they seem to introspection, and their underlying logical reality [McGinn] |
| 15651 | Instead of saying x has a property, we can say a formula is true of x - as long as we have 'true' [Halbach] |
| 16310 | A theory is some formulae and all of their consequences [Halbach] |
| 6042 | The quantifier is overrated as an analytical tool [McGinn] |
| 6067 | Existential quantifiers just express the quantity of things, leaving existence to the predicate 'exists' [McGinn] |
| 6069 | 'Partial quantifier' would be a better name than 'existential quantifier', as no existence would be implied [McGinn] |
| 6068 | We need an Intentional Quantifier ("some of the things we talk about.."), so existence goes into the proposition [McGinn] |
| 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] |
| 6070 | Existence is a primary quality, non-existence a secondary quality [McGinn] |
| 6062 | Existence can't be analysed as instantiating a property, as instantiation requires existence [McGinn] |
| 6065 | We can't analyse the sentence 'something exists' in terms of instantiated properties [McGinn] |
| 16345 | That Peano arithmetic is interpretable in ZF set theory is taken by philosophers as a reduction [Halbach] |
| 22427 | To explain object qualities, primary qualities must be more than mere sources of experience [McGinn] |
| 6082 | If causal power is the test for reality, that will exclude necessities and possibilities [McGinn] |
| 6075 | Facts are object-plus-extension, or property-plus-set-of-properties, or object-plus-property [McGinn] |
| 594 | Speusippus suggested underlying principles for every substance, and ended with a huge list [Speussipus, by Aristotle] |
| 18892 | Suppose a world where I'm from different gametes; add my gametes; which one is more me? [McGinn] |
| 12019 | McGinn falsely claims necessity of origin is a special case of the necessity of identity [Forbes,G on McGinn] |
| 6058 | Identity propositions are not always tautological, and have a key epistemic role [McGinn] |
| 6053 | Identity is as basic as any concept could ever be [McGinn] |
| 6043 | Type-identity is close similarity in qualities [McGinn] |
| 6044 | Qualitative identity is really numerical identity of properties [McGinn] |
| 6046 | Qualitative identity can be analysed into numerical identity of the type involved [McGinn] |
| 6045 | It is best to drop types of identity, and speak of 'identity' or 'resemblance' [McGinn] |
| 6066 | Existence is a property of all objects, but less universal than self-identity, which covers even conceivable objects [McGinn] |
| 6054 | Sherlock Holmes does not exist, but he is self-identical [McGinn] |
| 6047 | All identity is necessary, though identity statements can be contingently true [McGinn] |
| 6049 | Leibniz's Law says 'x = y iff for all P, Px iff Py' [McGinn] |
| 6048 | Leibniz's Law is so fundamental that it almost defines the concept of identity [McGinn] |
| 6050 | Leibniz's Law presupposes the notion of property identity [McGinn] |
| 16346 | Maybe necessity is a predicate, not the usual operator, to make it more like truth [Halbach] |
| 6080 | Modality is not objects or properties, but the type of binding of objects to properties [McGinn] |
| 6079 | If 'possible' is explained as quantification across worlds, there must be possible worlds [McGinn] |
| 6171 | Beliefs are states of the head that explain behaviour, and also items with referential truth-conditions [McGinn] |
| 22413 | Being red simply consists in looking red [McGinn] |
| 22415 | Relativity means differing secondary perceptions are not real disagreements [McGinn] |
| 22416 | Phenomenalism is correct for secondary qualities, so scepticism is there impossible [McGinn] |
| 22422 | Maybe all possible sense experience must involve both secondary and primary qualities [McGinn] |
| 22428 | You understood being red if you know the experience involved; not so with thngs being square [McGinn] |
| 22414 | You don't need to know how a square thing looks or feels to understand squareness [McGinn] |
| 22423 | Touch doesn't provide direct experience of primary qualities, because touch feels temperature [McGinn] |
| 22426 | We can perceive objectively, because primary qualities are not mind-created [McGinn] |
| 22412 | Lockean secondary qualities (unlike primaries) produce particular sensory experiences [McGinn] |
| 22421 | Could there be a mind which lacked secondary quality perception? [McGinn] |
| 22424 | Secondary qualities contain information; their variety would be superfluous otherwise [McGinn] |
| 22425 | The utility theory says secondary qualities give information useful to human beings [McGinn] |
| 7629 | We see objects 'directly' by representing them [McGinn] |
| 6081 | Necessity and possibility are big threats to the empiricist view of knowledge [McGinn] |
| 6071 | Scepticism about reality is possible because existence isn't part of appearances [McGinn] |
| 4691 | If all mental life were conscious, we would be unable to see things, or to process speech [McGinn] |
| 2539 | Mental modules for language, social, action, theory, space, emotion [McGinn] |
| 2545 | Free will is mental causation in action [McGinn] |
| 2543 | Brains aren't made of anything special, suggesting panpsychism [McGinn] |
| 7388 | McGinn invites surrender, by saying it is hopeless trying to imagine conscious machines [Dennett on McGinn] |
| 2540 | Examining mind sees no brain; examining brain sees no mind [McGinn] |
| 3185 | Multiple realisability rules out hidden essences and experts as the source of water- and gold-concepts [McGinn] |
| 22420 | The indexical perspective is subjective, incorrigible and constant [McGinn] |
| 18410 | Indexical thought is in relation to my self-consciousness [McGinn] |
| 22417 | Indexicals do not figure in theories of physics, because they are not explanatory causes [McGinn] |
| 18402 | Indexical concepts are indispensable, as we need them for the power to act [McGinn] |
| 4690 | If meaning is speaker's intentions, it can be reduced to propositional attitudes, and philosophy of mind [McGinn] |
| 6077 | Semantics should not be based on set-membership, but on instantiation of properties in objects [McGinn] |
| 2547 | There is information if there are symbols which refer, and which can combine into a truth or falsehood [McGinn] |
| 6074 | Clearly predicates have extensions (applicable objects), but are the extensions part of their meaning? [McGinn] |
| 22418 | I can know indexical truths a priori, unlike their non-indexical paraphrases [McGinn] |
| 16298 | We need propositions to ascribe the same beliefs to people with different languages [Halbach] |
| 2542 | Causation in the material world is energy-transfer, of motion, electricity or gravity [McGinn] |
| 6072 | If Satan is the most imperfect conceivable being, he must have non-existence [McGinn] |
| 6073 | I think the fault of the Ontological Argument is taking the original idea to be well-defined [McGinn] |
| 2632 | Speusippus said things were governed by some animal force rather than the gods [Speussipus, by Cicero] |