109 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] |
3942 | I do not believe in the existence of anything, if I see no reason to believe it [Berkeley] |
3952 | I know that nothing inconsistent can exist [Berkeley] |
16345 | That Peano arithmetic is interpretable in ZF set theory is taken by philosophers as a reduction [Halbach] |
3959 | There is no other substance, in a strict sense, than spirit [Berkeley] |
16346 | Maybe necessity is a predicate, not the usual operator, to make it more like truth [Halbach] |
3946 | A thing is shown to be impossible if a contradiction is demonstrated within its definition [Berkeley] |
20146 | 'Luck' is the unpredictable and inexplicable intersection of causal chains [Kekes] |
3958 | Since our ideas vary when the real things are said to be unchanged, they cannot be true copies [Berkeley] |
3943 | If existence is perceived directly, by which sense; if indirectly, how is it inferred from direct perception? [Berkeley] |
3931 | Sensible objects are just sets of sensible qualities [Berkeley] |
5192 | Berkeley did not deny material things; he merely said they must be defined through sensations [Berkeley, by Ayer] |
5174 | Berkeley needed a phenomenalist account of the self, as well as of material things [Ayer on Berkeley] |
1103 | 'To be is to be perceived' is a simple confusion of experience with its objects [Russell on Berkeley] |
6403 | For Berkelely, reality is ideas and a community of minds, including God's [Berkeley, by Grayling] |
3936 | Time is measured by the succession of ideas in our minds [Berkeley] |
3930 | There is no such thing as 'material substance' [Berkeley] |
3939 | I conceive a tree in my mind, but I cannot prove that its existence can be conceived outside a mind [Berkeley] |
3945 | There is nothing in nature which needs the concept of matter to explain it [Berkeley] |
3947 | Perceptions are ideas, and ideas exist in the mind, so objects only exist in the mind [Berkeley] |
3933 | Primary qualities (such as shape, solidity, mass) are held to really exist, unlike secondary qualities [Berkeley] |
3934 | A mite would see its own foot as large, though we would see it as tiny [Berkeley] |
3935 | The apparent size of an object varies with its distance away, so that can't be a property of the object [Berkeley] |
3937 | 'Solidity' is either not a sensible quality at all, or it is clearly relative to our senses [Berkeley] |
3940 | Distance is not directly perceived by sight [Berkeley] |
3957 | Immediate objects of perception, which some treat as appearances, I treat as the real things themselves [Berkeley] |
3953 | Real things and imaginary or dreamed things differ because the latter are much fainter [Berkeley] |
3938 | Geometry is originally perceived by senses, and so is not purely intellectual [Berkeley] |
3944 | It is possible that we could perceive everything as we do now, but nothing actually existed. [Berkeley] |
3932 | A hot hand and a cold hand will have different experiences in the same tepid water [Berkeley] |
3948 | Experience tells me that other minds exist independently from my own [Berkeley] |
3941 | How can that which is unthinking be a cause of thought? [Berkeley] |
5374 | Berkeley probably used 'idea' to mean both the act of apprehension and the thing apprehended [Russell on Berkeley] |
16298 | We need propositions to ascribe the same beliefs to people with different languages [Halbach] |
20169 | An action may be intended under one description, but not under another [Kekes] |
20149 | To control our actions better, make them result from our attitudes, not from circumstances [Kekes] |
3954 | Immorality is not in the action, but in the deviation of the will from moral law [Berkeley] |
19738 | Values are an attempt to achieve well-being by bringing contingencies under control [Kekes] |
20145 | Values help us to control life, by connecting it to what is stable and manageable [Kekes] |
20170 | Responsibility is unprovoked foreseeable harm, against society, arising from vicious character [Kekes] |
20165 | Reason and morality do not coincide; immorality can be reasonable, with an ideology [Kekes] |
20171 | Practical reason is not universal and impersonal, because it depends on what success is [Kekes] |
20175 | If morality has to be rational, then moral conflicts need us to be irrational and immoral [Kekes] |
20174 | Relativists say all values are relative; pluralists concede much of that, but not 'human' values [Kekes] |
20159 | Cultural values are interpretations of humanity, conduct, institutions, and evaluations [Kekes] |
20161 | The big value problems are evil (humanity), disenchantment (cultures), and boredom (individuals) [Kekes] |
20156 | We are bound to regret some values we never aspired to [Kekes] |
20150 | There are far more values than we can pursue, so they are optional possibilities [Kekes] |
20158 | Innumerable values arise for us, from our humanity, our culture, and our individuality [Kekes] |
20151 | Our attitudes include what possibilities we value, and also what is allowable, and unthinkable [Kekes] |
20152 | Unconditional commitments are our most basic convictions, saying what must never be done [Kekes] |
20153 | Doing the unthinkable damages ourselves, so it is more basic than any value [Kekes] |
20162 | Evil isn't explained by nature, by monsters, by uncharacteristic actions, or by society [Kekes] |
20154 | Control is the key to well-being [Kekes] |
20157 | Well-being needs correct attitudes and well-ordered commitments to local values [Kekes] |
20172 | Boredom destroys our ability to evaluate [Kekes] |
20173 | Boredom is apathy and restlessness, yearning for something interesting [Kekes] |
20155 | Society is alienating if it lacks our values, and its values repel us [Kekes] |
20164 | The ideal of an ideology is embodied in a text, a role model, a law of history, a dream of the past... [Kekes] |
20163 | Ideologies have beliefs about reality, ideals, a gap with actuality, and a program [Kekes] |
20148 | Equal distribution is no good in a shortage, because there might be no one satisfied [Kekes] |
3951 | There must be a God, because I and my ideas are not independent [Berkeley] |
3950 | There must be a God, because all sensible things must be perceived by him [Berkeley] |
3949 | It has been proved that creation is the workmanship of God, from its beauty and usefulness [Berkeley] |
3956 | People are responsible because they have limited power, though this ultimately derives from God [Berkeley] |
3955 | If sin is not just physical, we don't consider God the origin of sin because he causes physical events [Berkeley] |