106 ideas
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] |
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] |
16329 | Kripke-Feferman theory KF axiomatises Kripke fixed-points, with Strong Kleene logic with gluts [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] |
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] |
2392 | Properties supervene if you can't have one without the other [Chalmers] |
2393 | Logical supervenience is when one set of properties must be accompanied by another set [Chalmers] |
2394 | Natural supervenience is when one set of properties is always accompanied by another set [Chalmers] |
2398 | Reduction requires logical supervenience [Chalmers] |
16048 | Physicalism says in any two physically indiscernible worlds the positive facts are the same [Chalmers, by Bennett,K] |
2401 | All facts are either physical, experiential, laws of nature, second-order final facts, or indexical facts about me [Chalmers] |
16346 | Maybe necessity is a predicate, not the usual operator, to make it more like truth [Halbach] |
16424 | Strong metaphysical necessity allows fewer possible worlds than logical necessity [Chalmers] |
16425 | Metaphysical necessity is a bizarre, brute and inexplicable constraint on possibilities [Chalmers] |
16426 | How can we know the metaphysical impossibilities; the a posteriori only concerns this world [Chalmers] |
13956 | Kripke is often taken to be challenging a priori insights into necessity [Chalmers] |
13963 | Maybe logical possibility does imply conceivability - by an ideal mind [Chalmers] |
2407 | One can wrongly imagine two things being non-identical even though they are the same (morning/evening star) [Chalmers] |
2390 | We attribute beliefs to people in order to explain their behaviour [Chalmers] |
2397 | 'Perception' means either an action or a mental state [Chalmers] |
2422 | The structure of the retina has already simplified the colour information which hits it [Chalmers] |
2396 | Reductive explanation is not the be-all and the end-all of explanation [Chalmers] |
2426 | Why are minds homogeneous and brains fine-grained? [Chalmers] |
2391 | Can we be aware but not conscious? [Chalmers] |
2412 | Can we explain behaviour without consciousness? [Chalmers] |
2386 | Hard Problem: why brains experience things [Chalmers] |
2416 | What turns awareness into consciousness? [Chalmers] |
2423 | Going down the scale, where would consciousness vanish? [Chalmers] |
2403 | Nothing in physics even suggests consciousness [Chalmers] |
2400 | Is intentionality just causal connections? [Chalmers] |
2389 | Sometimes we don't notice our pains [Chalmers] |
2419 | Why should qualia fade during silicon replacement? [Chalmers] |
2402 | It seems possible to invert qualia [Chalmers] |
2415 | In blindsight both qualia and intentionality are missing [Chalmers] |
2414 | When distracted we can totally misjudge our own experiences [Chalmers] |
2409 | Maybe dualist interaction is possible at the quantum level? [Chalmers] |
2411 | Supervenience makes interaction laws possible [Chalmers] |
2424 | It is odd if experience is a very recent development [Chalmers] |
2413 | If I can have a zombie twin, my own behaviour doesn't need consciousness [Chalmers] |
2417 | Does consciousness arise from fine-grained non-reductive functional organisation? [Chalmers] |
2428 | Maybe the whole Chinese Room understands Chinese, though the person doesn't [Chalmers] |
2418 | The Chinese Mind doesn't seem conscious, but then nor do brains from outside [Chalmers] |
2406 | H2O causes liquidity, but no one is a dualist about that [Chalmers] |
2405 | Perhaps consciousness is physically based, but not logically required by that base [Chalmers] |
2395 | Zombies imply natural but not logical supervenience [Chalmers] |
9318 | Phenomenal consciousness is fundamental, with no possible nonphenomenal explanation [Chalmers, by Kriegel/Williford] |
2404 | Nothing external shows whether a mouse is conscious [Chalmers] |
2429 | Temperature (etc.) is agreed to be reducible, but it is multiply realisable [Chalmers] |
18403 | Indexicals may not be objective, but they are a fact about the world as I see it [Chalmers] |
14708 | Rationalist 2D semantics posits necessary relations between meaning, apriority, and possibility [Chalmers, by Schroeter] |
13958 | The 'primary intension' is non-empirical, and fixes extensions based on the actual-world reference [Chalmers] |
2399 | Meaning has split into primary ("watery stuff"), and secondary counterfactual meaning ("H2O") [Chalmers] |
13959 | The 'secondary intension' is determined by rigidifying (as H2O) the 'water' picked out in the actual world [Chalmers] |
13957 | Primary and secondary intensions are the a priori (actual) and a posteriori (counterfactual) aspects of meaning [Chalmers] |
13961 | We have 'primary' truth-conditions for the actual world, and derived 'secondary' ones for counterfactual worlds [Chalmers] |
13962 | Two-dimensional semantics gives a 'primary' and 'secondary' proposition for each statement [Chalmers] |
16298 | We need propositions to ascribe the same beliefs to people with different languages [Halbach] |
13960 | In two-dimensional semantics we have two aspects to truth in virtue of meaning [Chalmers] |
6968 | Some people think there are ethical facts, but of a 'queer' sort [Ayer] |
6972 | A right attitude is just an attitude one is prepared to stand by [Ayer] |
6973 | Moral theories are all meta-ethical, and are neutral as regards actual conduct [Ayer] |
6974 | Moral judgements cannot be the logical consequence of a moral philosophy [Ayer] |
6971 | I would describe intuitions of good as feelings of approval [Ayer] |
6969 | Approval of historical or fictional murders gives us leave to imitate them [Ayer] |
6970 | Moral judgements are not expressions, but are elements in a behaviour pattern [Ayer] |
16427 | Presumably God can do anything which is logically possible [Chalmers] |