163 ideas
| 7504 | Modern science comes from Descartes' view that knowledge doesn't need moral purity [Descartes, by Foucault] |
| 16325 | Analysis rests on natural language, but its ideal is a framework which revises language [Halbach] |
| 1569 | Descartes impoverished the classical idea of logos, and it no longer covered human experience [Roochnik on Descartes] |
| 2248 | Reason says don't assent to uncertain principles, just as much as totally false ones [Descartes] |
| 2857 | Since Plato all philosophers have followed the herd, except Descartes, stuck in superficial reason [Nietzsche on Descartes] |
| 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] |
| 3641 | It is circular to make truth depend on believing God's existence is true [Arnauld on Descartes] |
| 4524 | Descartes is right that in the Christian view only God can guarantee the reliability of senses [Nietzsche on Descartes] |
| 2290 | Once it is clear that there is a God who is no deceiver, I conclude that clear and distinct perceptions must be true [Descartes] |
| 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] |
| 2266 | My general rule is that everything that I perceive clearly and distinctly is true [Descartes] |
| 4301 | Someone may think a thing is 'clear and distinct', but be wrong [Leibniz on Descartes] |
| 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] |
| 10054 | Arithmetic and geometry achieve some certainty without worrying about existence [Descartes] |
| 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] |
| 2252 | Surely maths is true even if I am dreaming? [Descartes] |
| 2430 | I can learn the concepts of duration and number just from observing my own thoughts [Descartes] |
| 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] |
| 10494 | Several words may label a category; one word can name several categories; some categories lack words [Ellen] |
| 2297 | If I can separate two things in my understanding, then God can separate them in reality [Descartes] |
| 3628 | Substance cannot be conceived or explained to others [Gassendi on Descartes] |
| 16631 | If we remove surface qualities from wax, we have an extended, flexible, changeable thing [Descartes] |
| 17865 | Descartes gives an essence by an encapsulating formula [Descartes, by Almog] |
| 16346 | Maybe necessity is a predicate, not the usual operator, to make it more like truth [Halbach] |
| 2301 | We know by thought that what is done cannot be undone [Descartes] |
| 3642 | Pythagoras' Theorem doesn't cease to be part of the essence of triangles just because we doubt it [Arnauld on Descartes] |
| 20190 | Belief is not an intellectual state or act, because propositions are affirmed or denied by the will [Descartes, by Zagzebski] |
| 1585 | Descartes tried to model reason on maths instead of 'logos' [Roochnik on Descartes] |
| 1582 | Labelling slightly doubtful things as false is irrational [Roochnik on Descartes] |
| 2256 | Maybe there is only one certain fact, which is that nothing is certain [Descartes] |
| 6914 | Descartes transformed 'God is thinkable, so he exists' into 'I think, so I exist' [Descartes, by Feuerbach] |
| 4641 | In the Meditations version of the Cogito he says "I am; I exist", which avoids presenting it as an argument [Descartes, by Baggini /Fosl] |
| 6929 | Modern philosophy set the self-conscious ego in place of God [Descartes, by Feuerbach] |
| 3849 | "I think therefore I am" is the absolute truth of consciousness [Sartre on Descartes] |
| 2258 | I must even exist if I am being deceived by something [Descartes] |
| 2259 | "I am, I exist" is necessarily true every time I utter it or conceive it in my mind [Descartes] |
| 3160 | The Cogito is a transcendental argument, not a piece of a priori knowledge [Rey on Descartes] |
| 2260 | If I don't think, there is no reason to think that I exist [Descartes] |
| 1117 | The Cogito proves subjective experience is basic, but makes false claims about the Self [Russell on Descartes] |
| 2873 | Maybe 'I' am not the thinker, but something produced by thought [Nietzsche on Descartes] |
| 3623 | The Cogito only works if you already understand what thought and existence are [Mersenne on Descartes] |
| 1369 | It is a precondition of the use of the word 'I' that I exist [Ayer on Descartes] |
| 5360 | The thing which experiences may be momentary, and change with the next experience [Russell on Descartes] |
| 2870 | 'I think' assumes I exist, that thinking is known and caused, and that I am doing it [Nietzsche on Descartes] |
| 5188 | A thought doesn't imply other thoughts, or enough thoughts to make up a self [Ayer on Descartes] |
| 3624 | That I perform an activity (thinking) doesn't prove what type of thing I am [Hobbes on Descartes] |
| 3120 | Autistic children seem to use the 'I' concept without seeing themselves as thinkers [Segal on Descartes] |
| 4526 | The Cogito assumes a priori the existence of substance, when actually it is a grammatical custom [Nietzsche on Descartes] |
| 5579 | How can we infer that all thinking involves self-consciousness, just from my own case? [Kant on Descartes] |
| 5580 | My self is not an inference from 'I think', but a presupposition of it [Kant on Descartes] |
| 5587 | We cannot give any information a priori about the nature of the 'thing that thinks' [Kant on Descartes] |
| 5588 | The fact that I am a subject is not enough evidence to show that I am a substantial object [Kant on Descartes] |
| 13923 | Descartes' claim to know his existence before his essence is misleading or absurd [Descartes, by Lowe] |
| 6930 | Modern self-consciousness is a doubtful abstraction; only senses and feelings are certain [Feuerbach on Descartes] |
| 2261 | My perceiving of things may be false, but my seeming to perceive them cannot be false [Descartes] |
| 2257 | I myself could be the author of all these self-delusions [Descartes] |
| 2279 | A triangle has a separate non-invented nature, shown by my ability to prove facts about it [Descartes] |
| 6490 | For Descartes, objects have one primary quality, which is geometrical [Descartes, by Robinson,H] |
| 2295 | Why does pain make us sad? [Descartes] |
| 3627 | Dogs can make the same judgements as us about variable things [Gassendi on Descartes] |
| 2265 | We perceive objects by intellect, not by senses or imagination [Descartes] |
| 2263 | The wax is not perceived by the senses, but by the mind alone [Descartes] |
| 2264 | We don't 'see' men in heavy clothes, we judge them to be men [Descartes] |
| 2247 | To achieve good science we must rebuild from the foundations [Descartes] |
| 2255 | Only one certainty is needed for progress (like a lever's fulcrum) [Descartes] |
| 2251 | Even if my body and objects are imaginary, there may be simpler things which are true [Descartes] |
| 6347 | Descartes can't begin again, because sceptics doubt cognitive processes as well as beliefs [Pollock/Cruz on Descartes] |
| 2296 | If pain is felt in a lost limb, I cannot be certain that a felt pain exists in my real limbs [Descartes] |
| 3620 | We correct sense errors with other senses, not intellect [Mersenne on Descartes] |
| 3619 | The senses can only report, so perception errors are in the judgment [Gassendi on Descartes] |
| 2249 | It is prudent never to trust your senses if they have deceived you even once [Descartes] |
| 2253 | God may have created nothing, but made his creation appear to me as it does now [Descartes] |
| 2254 | To achieve full scepticism, I imagine a devil who deceives me about the external world and my own body and senses [Descartes] |
| 2305 | Waking actions are joined by memory to all our other actions, unlike actions of which we dream [Descartes] |
| 2294 | I can only sense an object if it is present, and can't fail to sense it when it is [Descartes] |
| 4862 | Can the pineal gland be moved more slowly or quickly by the mind than by animal spirits? [Spinoza on Descartes] |
| 3850 | We discovers others as well as ourselves in the Cogito [Sartre on Descartes] |
| 2302 | Faculties of the mind aren't parts, as one mind uses them [Descartes] |
| 3151 | Descartes put thought at the centre of the mind problem, but we put sensation [Rey on Descartes] |
| 21800 | Descartes mentions many cognitive faculties, but reduces them to will and intellect [Descartes, by Schmid] |
| 1399 | Imagination and sensation are non-essential to mind [Descartes] |
| 1400 | Some cause must unite the separate temporal sections of a person [Descartes] |
| 1401 | Since I only observe myself to be thinking, I conclude that that is my essence [Descartes] |
| 2299 | I can exist without imagination and sensing, but they can't exist without me [Descartes] |
| 6907 | For Descartes a person's essence is the mind because objects are perceived by mind, not senses [Descartes, by Feuerbach] |
| 2283 | Our 'will' just consists of the feeling that when we are motivated to do something, there are no external pressures [Descartes] |
| 2282 | My capacity to make choices with my free will extends as far as any faculty ever could [Descartes] |
| 2276 | The mind is a non-extended thing which thinks [Descartes] |
| 2298 | Mind is not extended, unlike the body [Descartes] |
| 3423 | Descartes is a substance AND property dualist [Descartes, by Kim] |
| 2303 | The mind is utterly indivisible [Descartes] |
| 6153 | Interaction between mental and physical seems to violate the principle of conservation of energy [Rowlands on Descartes] |
| 3625 | The 'thinking thing' may be the physical basis of the mind [Hobbes on Descartes] |
| 2552 | Knowing different aspects of brain/mind doesn't make them different [Rorty on Descartes] |
| 4305 | Descartes gives no clear criterion for individuating mental substances [Cottingham on Descartes] |
| 4861 | Does Descartes have a clear conception of how mind unites with body? [Spinoza on Descartes] |
| 6540 | Even Descartes may concede that mental supervenes on neuroanatomical [Lycan on Descartes] |
| 7733 | Superman's strength is indubitable, Clark Kent's is doubtful, so they are not the same? [Maslin on Descartes] |
| 5686 | In some thoughts I grasp a subject, but also I will or fear or affirm or deny it [Descartes] |
| 4017 | Descartes created the modern view of rationality, as an internal feature instead of an external vision [Descartes, by Taylor,C] |
| 2284 | I make errors because my will extends beyond my understanding [Descartes] |
| 5685 | True ideas are images, such as of a man, a chimera, or God [Descartes] |
| 3629 | All ideas are adventitious, and come from the senses [Gassendi on Descartes] |
| 2273 | The ideas of God and of my self are innate in me [Descartes] |
| 2285 | I can think of innumerable shapes I have never experienced [Descartes] |
| 2286 | The idea of a supremely perfect being is within me, like the basic concepts of mathematics [Descartes] |
| 16298 | We need propositions to ascribe the same beliefs to people with different languages [Halbach] |
| 2280 | Many causes are quite baffling, so it is absurd to deduce causes from final purposes [Descartes] |
| 2272 | There must be at least as much in the cause as there is in the effect [Descartes] |
| 2289 | Nothing apart from God could have essential existence, and such a being must be unique and eternal [Descartes] |
| 2269 | God the creator is an intelligent, infinite, powerful substance [Descartes] |
| 2275 | It is self-evident that deception is a natural defect, so God could not be a deceiver [Descartes] |
| 2287 | Existence and God's essence are inseparable, like a valley and a mountain, or a triangle and its properties [Descartes] |
| 2274 | The idea of God in my mind is like the mark a craftsman puts on his work [Descartes] |
| 2268 | One idea leads to another, but there must be an initial idea that contains the reality of all the others [Descartes] |
| 2288 | I cannot think of a supremely perfect being without the supreme perfection of existence [Descartes] |
| 3632 | We mustn't worship God as an image because we have no idea of him [Hobbes on Descartes] |
| 3633 | We can never conceive of an infinite being [Gassendi on Descartes] |
| 5036 | Descartes cannot assume that a most perfect being exists without contradictions [Leibniz on Descartes] |
| 3638 | Existence is not a perfection; it is what makes perfection possible [Gassendi on Descartes] |
| 2277 | Since God does not wish to deceive me, my judgement won't make errors if I use it properly [Descartes] |
| 2278 | Error arises because my faculty for judging truth is not infinite [Descartes] |
| 3636 | God didn't give us good judgement even about our own lives [Gassendi on Descartes] |
| 2281 | If we ask whether God's works are perfect, we must not take a narrow viewpoint, but look at the universe as a whole [Descartes] |