193 ideas
7504 | Modern science comes from Descartes' view that knowledge doesn't need moral purity [Descartes, by Foucault] |
224 | When questions are doubtful we should concentrate not on objects but on ideas of the intellect [Plato] |
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] |
232 | Opposites are as unlike as possible [Plato] |
8937 | Plato's 'Parmenides' is the greatest artistic achievement of the ancient dialectic [Hegel on Plato] |
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] |
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] |
10987 | Three traditional names of rules are 'Simplification', 'Addition' and 'Disjunctive Syllogism' [Read] |
11004 | Necessity is provability in S4, and true in all worlds in S5 [Read] |
11018 | There are fuzzy predicates (and sets), and fuzzy quantifiers and modifiers [Read] |
11011 | Same say there are positive, negative and neuter free logics [Read] |
11020 | Realisms like the full Comprehension Principle, that all good concepts determine sets [Read] |
10986 | Not all validity is captured in first-order logic [Read] |
10972 | The non-emptiness of the domain is characteristic of classical logic [Read] |
11024 | Semantics must precede proof in higher-order logics, since they are incomplete [Read] |
10985 | We should exclude second-order logic, precisely because it captures arithmetic [Read] |
10970 | A theory of logical consequence is a conceptual analysis, and a set of validity techniques [Read] |
10984 | Logical consequence isn't just a matter of form; it depends on connections like round-square [Read] |
10054 | Arithmetic and geometry achieve some certainty without worrying about existence [Descartes] |
10973 | A theory is logically closed, which means infinite premisses [Read] |
11007 | Quantifiers are second-order predicates [Read] |
10978 | In second-order logic the higher-order variables range over all the properties of the objects [Read] |
10971 | A logical truth is the conclusion of a valid inference with no premisses [Read] |
10988 | Any first-order theory of sets is inadequate [Read] |
10974 | Compactness is when any consequence of infinite propositions is the consequence of a finite subset [Read] |
10975 | Compactness does not deny that an inference can have infinitely many premisses [Read] |
10977 | Compactness blocks the proof of 'for every n, A(n)' (as the proof would be infinite) [Read] |
10976 | Compactness makes consequence manageable, but restricts expressive power [Read] |
13986 | Plato found antinomies in ideas, Kant in space and time, and Bradley in relations [Plato, by Ryle] |
14150 | Plato's 'Parmenides' is perhaps the best collection of antinomies ever made [Russell on Plato] |
11014 | Self-reference paradoxes seem to arise only when falsity is involved [Read] |
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] |
11025 | Infinite cuts and successors seems to suggest an actual infinity there waiting for us [Read] |
10979 | Although second-order arithmetic is incomplete, it can fully model normal arithmetic [Read] |
10980 | Second-order arithmetic covers all properties, ensuring categoricity [Read] |
10997 | Von Neumann numbers are helpful, but don't correctly describe numbers [Read] |
16150 | One is, so numbers exist, so endless numbers exist, and each one must partake of being [Plato] |
229 | The one was and is and will be and was becoming and is becoming and will become [Plato] |
21821 | Plato's Parmenides has a three-part theory, of Primal One, a One-Many, and a One-and-Many [Plato, by Plotinus] |
221 | Absolute ideas, such as the Good and the Beautiful, cannot be known by us [Plato] |
11016 | Would a language without vagueness be usable at all? [Read] |
11019 | Supervaluations say there is a cut-off somewhere, but at no particular place [Read] |
11012 | A 'supervaluation' gives a proposition consistent truth-value for classical assignments [Read] |
11013 | Identities and the Indiscernibility of Identicals don't work with supervaluations [Read] |
227 | You must always mean the same thing when you utter the same name [Plato] |
223 | If you deny that each thing always stays the same, you destroy the possibility of discussion [Plato] |
211 | If admirable things have Forms, maybe everything else does as well [Plato] |
219 | If absolute ideas existed in us, they would cease to be absolute [Plato] |
228 | Greatness and smallness must exist, to be opposed to one another, and come into being in things [Plato] |
16151 | Plato moves from Forms to a theory of genera and principles in his later work [Plato, by Frede,M] |
210 | It would be absurd to think there were abstract Forms for vile things like hair, mud and dirt [Plato] |
220 | The concept of a master includes the concept of a slave [Plato] |
218 | Participation is not by means of similarity, so we are looking for some other method of participation [Plato] |
213 | Each idea is in all its participants at once, just as daytime is a unity but in many separate places at once [Plato] |
216 | If things are made alike by participating in something, that thing will be the absolute idea [Plato] |
215 | If things partake of ideas, this implies either that everything thinks, or that everything actually is thought [Plato] |
212 | The whole idea of each Form must be found in each thing which participates in it [Plato] |
214 | If absolute greatness and great things are seen as the same, another thing appears which makes them seem great [Plato] |
217 | Nothing can be like an absolute idea, because a third idea intervenes to make them alike (leading to a regress) [Plato] |
10995 | A haecceity is a set of individual properties, essential to each thing [Read] |
15851 | Parts must belong to a created thing with a distinct form [Plato] |
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] |
15846 | In Parmenides, if composition is identity, a whole is nothing more than its parts [Plato, by Harte,V] |
16631 | If we remove surface qualities from wax, we have an extended, flexible, changeable thing [Descartes] |
15849 | Plato says only a one has parts, and a many does not [Plato, by Harte,V] |
15850 | Anything which has parts must be one thing, and parts are of a one, not of a many [Plato] |
13259 | It seems that the One must be composed of parts, which contradicts its being one [Plato] |
17865 | Descartes gives an essence by an encapsulating formula [Descartes, by Almog] |
15847 | Two things relate either as same or different, or part of a whole, or the whole of the part [Plato] |
11001 | Equating necessity with truth in every possible world is the S5 conception of necessity [Read] |
10992 | The point of conditionals is to show that one will accept modus ponens [Read] |
10989 | The standard view of conditionals is that they are truth-functional [Read] |
11017 | Some people even claim that conditionals do not express propositions [Read] |
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] |
10983 | Knowledge of possible worlds is not causal, but is an ontology entailed by semantics [Read] |
10982 | How can modal Platonists know the truth of a modal proposition? [Read] |
10996 | Actualism is reductionist (to parts of actuality), or moderate realist (accepting real abstractions) [Read] |
10981 | A possible world is a determination of the truth-values of all propositions of a domain [Read] |
11000 | If worlds are concrete, objects can't be present in more than one, and can only have counterparts [Read] |
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] |
10998 | The mind abstracts ways things might be, which are nonetheless real [Read] |
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] |
11005 | Negative existentials with compositionality make the whole sentence meaningless [Read] |
10966 | A proposition objectifies what a sentence says, as indicative, with secure references [Read] |
222 | Only a great person can understand the essence of things, and an even greater person can teach it [Plato] |
2280 | Many causes are quite baffling, so it is absurd to deduce causes from final purposes [Descartes] |
225 | The unlimited has no shape and is endless [Plato] |
233 | Some things do not partake of the One [Plato] |
2062 | The only movement possible for the One is in space or in alteration [Plato] |
231 | Everything partakes of the One in some way [Plato] |
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] |
234 | We couldn't discuss the non-existence of the One without knowledge of it [Plato] |
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] |
2288 | I cannot think of a supremely perfect being without the supreme perfection of existence [Descartes] |
2268 | One idea leads to another, but there must be an initial idea that contains the reality of all the others [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] |
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] |
2277 | Since God does not wish to deceive me, my judgement won't make errors if I use it properly [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] |