71 ideas
| 3656 | The greatest good for a state is true philosophers [Descartes] |
| 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] |
| 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] |
| 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] |
| 16319 | Compositional Truth CT proves generalisations, so is preferred in discussions of deflationism [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] |
| 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] |
| 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] |
| 16345 | That Peano arithmetic is interpretable in ZF set theory is taken by philosophers as a reduction [Halbach] |
| 16744 | All powers can be explained by obvious features like size, shape and motion of matter [Descartes] |
| 5016 | Five universals: genus, species, difference, property, accident [Descartes] |
| 5015 | A universal is a single idea applied to individual things that are similar to one another [Descartes] |
| 16630 | If we perceive an attribute, we infer the existence of some substance [Descartes] |
| 5013 | A substance needs nothing else in order to exist [Descartes] |
| 16633 | A substance has one principal property which is its nature and essence [Descartes] |
| 16346 | Maybe necessity is a predicate, not the usual operator, to make it more like truth [Halbach] |
| 3658 | Total doubt can't include your existence while doubting [Descartes] |
| 5005 | I think, therefore I am, because for a thinking thing to not exist is a contradiction [Descartes] |
| 5006 | 'Thought' is all our conscious awareness, including feeling as well as understanding [Descartes] |
| 5012 | 'Nothing comes from nothing' is an eternal truth found within the mind [Descartes] |
| 5004 | We can know basic Principles without further knowledge, but not the other way round [Descartes] |
| 5014 | We can understand thinking occuring without imagination or sensation [Descartes] |
| 4921 | Quantum states in microtubules could bind brain activity to produce consciousness [Penrose] |
| 5017 | In thinking we shut ourselves off from other substances, showing our identity and separateness [Descartes] |
| 5010 | Our free will is so self-evident to us that it must be a basic innate idea [Descartes] |
| 5011 | There are two ultimate classes of existence: thinking substance and extended substance [Descartes] |
| 5018 | Even if tightly united, mind and body are different, as God could separate them [Descartes] |
| 5007 | Most errors of judgement result from an inaccurate perception of the facts [Descartes] |
| 16298 | We need propositions to ascribe the same beliefs to people with different languages [Halbach] |
| 5009 | We do not praise the acts of an efficient automaton, as their acts are necessary [Descartes] |
| 5008 | The greatest perfection of man is to act by free will, and thus merit praise or blame [Descartes] |
| 15987 | Physics only needs geometry or abstract mathematics, which can explain and demonstrate everything [Descartes] |
| 12730 | We will not try to understand natural or divine ends, or final causes [Descartes] |
| 16601 | Matter is not hard, heavy or coloured, but merely extended in space [Descartes] |