100 ideas
| 8013 | In the Reformation, morality became unconditional but irrational, individually autonomous, and secular [MacIntyre] |
| 8021 | The Levellers and the Diggers mark a turning point in the history of morality [MacIntyre] |
| 8060 | In the 17th-18th centuries morality offered a cure for egoism, through altruism [MacIntyre] |
| 8053 | Twentieth century social life is re-enacting eighteenth century philosophy [MacIntyre] |
| 8047 | Philosophy has been marginalised by its failure in the Enlightenment to replace religion [MacIntyre] |
| 16325 | Analysis rests on natural language, but its ideal is a framework which revises language [Halbach] |
| 8062 | Proof is a barren idea in philosophy, and the best philosophy never involves proof [MacIntyre] |
| 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] |
| 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] |
| 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] |
| 15648 | Instead of a truth definition, add a primitive truth predicate, and axioms for how it works [Halbach] |
| 15655 | Should axiomatic truth be 'conservative' - not proving anything apart from implications of the axioms? [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] |
| 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] |
| 15650 | Axiomatic theories of truth need a weak logical framework, and not a strong metatheory [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] |
| 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] |
| 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] |
| 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] |
| 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] |
| 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] |
| 16344 | Soundness must involve truth; the soundness of PA certainly needs it [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] |
| 6007 | If you know your father, but don't recognise your father veiled, you know and don't know the same person [Eubulides, by Dancy,R] |
| 16347 | Many new paradoxes may await us when we study interactions between frameworks [Halbach] |
| 6006 | If you say truly that you are lying, you are lying [Eubulides, by Dancy,R] |
| 16336 | The liar paradox applies truth to a negated truth (but the conditional will serve equally) [Halbach] |
| 6008 | Removing one grain doesn't destroy a heap, so a heap can't be destroyed [Eubulides, by Dancy,R] |
| 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] |
| 16346 | Maybe necessity is a predicate, not the usual operator, to make it more like truth [Halbach] |
| 8052 | To find empiricism and science in the same culture is surprising, as they are really incompatible [MacIntyre] |
| 10356 | Relativism can be seen as about the rationality of different cultural traditions [MacIntyre, by Kusch] |
| 8057 | Unpredictability doesn't entail inexplicability, and predictability doesn't entail explicability [MacIntyre] |
| 8054 | Social sciences discover no law-like generalisations, and tend to ignore counterexamples [MacIntyre] |
| 8006 | When Aristotle speaks of soul he means something like personality [MacIntyre] |
| 21050 | I can only make decisions if I see myself as part of a story [MacIntyre] |
| 8056 | AI can't predict innovation, or consequences, or external relations, or external events [MacIntyre] |
| 16298 | We need propositions to ascribe the same beliefs to people with different languages [Halbach] |
| 8059 | The good life for man is the life spent seeking the good life for man [MacIntyre] |
| 8034 | We still have the appearance and language of morality, but we no longer understand it [MacIntyre] |
| 8036 | Unlike expressions of personal preference, evaluative expressions do not depend on context [MacIntyre] |
| 8049 | Moral judgements now are anachronisms from a theistic age [MacIntyre] |
| 8045 | The failure of Enlightenment attempts to justify morality will explain our own culture [MacIntyre] |
| 8051 | Mention of 'intuition' in morality means something has gone wrong with the argument [MacIntyre] |
| 8048 | When 'man' is thought of individually, apart from all roles, it ceases to be a functional concept [MacIntyre] |
| 8035 | In trying to explain the type of approval involved, emotivists are either silent, or viciously circular [MacIntyre] |
| 8037 | The expression of feeling in a sentence is in its use, not in its meaning [MacIntyre] |
| 8040 | Emotivism cannot explain the logical terms in moral discourse ('therefore', 'if..then') [MacIntyre] |
| 8042 | Nowadays most people are emotivists, and it is embodied in our culture [MacIntyre] |
| 8002 | Sophists don't distinguish a person outside one social order from someone outside all order [MacIntyre] |
| 8012 | The value/fact logical gulf is misleading, because social facts involve values [MacIntyre] |
| 8005 | 'Happiness' is a bad translation of 'eudaimonia', which includes both behaving and faring well [MacIntyre] |
| 8058 | Maybe we can only understand rules if we first understand the virtues [MacIntyre] |
| 7097 | Virtue is secondary to a role-figure, defined within a culture [MacIntyre, by Statman] |
| 8043 | Characters are the masks worn by moral philosophies [MacIntyre] |
| 8061 | If morality just is emotion, there are no external criteria for judging emotions [MacIntyre] |
| 8001 | 'Dikaiosune' is justice, but also fairness and personal integrity [MacIntyre] |
| 8023 | My duties depend on my identity, which depends on my social relations [MacIntyre] |
| 8038 | Since Moore thinks the right action produces the most good, he is a utilitarian [MacIntyre] |
| 8022 | I am naturally free if I am not tied to anyone by a contract [MacIntyre] |
| 8050 | There are no natural or human rights, and belief in them is nonsense [MacIntyre] |
| 23080 | Liberals debate how conservative or radical to be, but don't question their basics [MacIntyre] |
| 8031 | Fans of natural rights or laws can't agree on what the actual rights or laws are [MacIntyre] |
| 8055 | If God is omniscient, he confronts no as yet unmade decisions, so decisions are impossible [MacIntyre] |
| 8008 | The Bible is a story about God in which humans are incidental characters [MacIntyre] |