89 ideas
21634 | Metaphysics is (supposedly) first the ontology, then in general what things are like [Hofweber] |
13734 | Modern Quinean metaphysics is about what exists, but Aristotelian metaphysics asks about grounding [Schaffer,J] |
13751 | If you tore the metaphysics out of philosophy, the whole enterprise would collapse [Schaffer,J] |
21666 | 'Fundamentality' is either a superficial idea, or much too obscure [Hofweber] |
16325 | Analysis rests on natural language, but its ideal is a framework which revises language [Halbach] |
13743 | We should not multiply basic entities, but we can have as many derivative entities as we like [Schaffer,J] |
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] |
16339 | Truth axioms prove objects exist, so truth doesn't seem to be a logical notion [Halbach] |
16330 | Truth-value 'gluts' allow two truth values together; 'gaps' give a partial conception of truth [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] |
16294 | Axiomatic truth doesn't presuppose a truth-definition, though it could admit it at a later stage [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] |
16326 | The main semantic theories of truth are Kripke's theory, and revisions semantics [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] |
16322 | CT proves PA consistent, which PA can't do on its own, so CT is not conservative over PA [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] |
21640 | 'It's true that Fido is a dog' conjures up a contrast class, of 'it's false' or 'it's unlikely' [Hofweber] |
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] |
16320 | Some say deflationism is axioms which are conservative over the base theory [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] |
21657 | Since properties can have properties, some theorists rank them in 'types' [Hofweber] |
16310 | A theory is some formulae and all of their consequences [Halbach] |
21653 | Maybe not even names are referential, but are just by used by speakers to refer [Hofweber] |
21636 | 'Singular terms' are not found in modern linguistics, and are not the same as noun phrases [Hofweber] |
21637 | If two processes are said to be identical, that doesn't make their terms refer to entities [Hofweber] |
21643 | The inferential quantifier focuses on truth; the domain quantifier focuses on reality [Hofweber] |
16342 | You cannot just say all of Peano arithmetic is true, as 'true' isn't part of the system [Halbach] |
16344 | Soundness must involve truth; the soundness of PA certainly needs it [Halbach] |
16341 | Normally we only endorse a theory if we believe it to be sound [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] |
21644 | Numbers are used as singular terms, as adjectives, and as symbols [Hofweber] |
21646 | The Amazonian Piraha language is said to have no number words [Hofweber] |
21665 | The fundamental theorem of arithmetic is that all numbers are composed uniquely of primes [Hofweber] |
21649 | How can words be used for counting if they are objects? [Hofweber] |
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] |
13741 | If 'there are red roses' implies 'there are roses', then 'there are prime numbers' implies 'there are numbers' [Schaffer,J] |
21647 | Logicism makes sense of our ability to know arithmetic just by thought [Hofweber] |
16308 | Set theory was liberated early from types, and recent truth-theories are exploring type-free [Halbach] |
21648 | Neo-Fregeans are dazzled by a technical result, and ignore practicalities [Hofweber] |
13748 | Grounding is unanalysable and primitive, and is the basic structuring concept in metaphysics [Schaffer,J] |
16345 | That Peano arithmetic is interpretable in ZF set theory is taken by philosophers as a reduction [Halbach] |
13747 | Supervenience is just modal correlation [Schaffer,J] |
21664 | Supervenience offers little explanation for things which necessarily go together [Hofweber] |
13744 | The cosmos is the only fundamental entity, from which all else exists by abstraction [Schaffer,J] |
21660 | Reality can be seen as the totality of facts, or as the totality of things [Hofweber] |
21661 | There are probably ineffable facts, systematically hidden from us [Hofweber] |
13739 | Maybe categories are just the different ways that things depend on basic substances [Schaffer,J] |
21652 | Our perceptual beliefs are about ordinary objects, not about simples arranged chair-wise [Hofweber] |
13742 | There exist heaps with no integral unity, so we should accept arbitrary composites in the same way [Schaffer,J] |
13752 | The notion of 'grounding' can explain integrated wholes in a way that mere aggregates can't [Schaffer,J] |
16346 | Maybe necessity is a predicate, not the usual operator, to make it more like truth [Halbach] |
21663 | Counterfactuals are essential for planning, and learning from mistakes [Hofweber] |
13749 | Belief in impossible worlds may require dialetheism [Schaffer,J] |
13740 | 'Moorean certainties' are more credible than any sceptical argument [Schaffer,J] |
21654 | The "Fido"-Fido theory of meaning says every expression in a language has a referent [Hofweber] |
21641 | Inferential role semantics is an alternative to semantics that connects to the world [Hofweber] |
21638 | Syntactic form concerns the focus of the sentence, as well as the truth-conditions [Hofweber] |
21658 | Properties can be expressed in a language despite the absence of a single word for them [Hofweber] |
21659 | 'Being taller than this' is a predicate which can express many different properties [Hofweber] |
21655 | Compositonality is a way to build up the truth-conditions of a sentence [Hofweber] |
21656 | Proposition have no content, because they are content [Hofweber] |
21635 | Without propositions there can be no beliefs or desires [Hofweber] |
21662 | Do there exist thoughts which we are incapable of thinking? [Hofweber] |
16298 | We need propositions to ascribe the same beliefs to people with different languages [Halbach] |
21645 | 'Semantic type coercion' is selecting the reading of a word to make the best sense [Hofweber] |
21639 | 'Background deletion' is appropriately omitting background from an answer [Hofweber] |