132 ideas
| 5361 | Philosophers must get used to absurdities [Russell] |
| 1695 | Without extensive examination firm statements are hard, but studying the difficulties is profitable [Aristotle] |
| 5368 | Philosophy verifies that our hierarchy of instinctive beliefs is harmonious and consistent [Russell] |
| 5432 | Metaphysics cannot give knowledge of the universe as a whole [Russell] |
| 5434 | Philosophy is similar to science, and has no special source of wisdom [Russell] |
| 5405 | The law of contradiction is not a 'law of thought', but a belief about things [Russell] |
| 5396 | Three Laws of Thought: identity, contradiction, and excluded middle [Russell] |
| 1698 | Both sides of contraries need not exist (as health without sickness, white without black) [Aristotle] |
| 1697 | The contrary of good is bad, but the contrary of bad is either good or another evil [Aristotle] |
| 11034 | The differentiae of genera which are different are themselves different in kind [Aristotle] |
| 5420 | Truth is a property of a belief, but dependent on its external relations, not its internal qualities [Russell] |
| 5419 | Truth and falsehood are properties of beliefs and statements [Russell] |
| 5417 | A good theory of truth must make falsehood possible [Russell] |
| 18367 | A true existence statement has its truth caused by the existence of the thing [Aristotle] |
| 7395 | Truth as congruence may work for complex beliefs, but not for simple beliefs about existence [Joslin on Russell] |
| 5428 | Beliefs are true if they have corresponding facts, and false if they don't [Russell] |
| 5421 | The coherence theory says falsehood is failure to cohere, and truth is fitting into a complete system of Truth [Russell] |
| 5423 | If we suspend the law of contradiction, nothing will appear to be incoherent [Russell] |
| 5424 | Coherence is not the meaning of truth, but an important test for truth [Russell] |
| 5422 | More than one coherent body of beliefs seems possible [Russell] |
| 5401 | The mortality of Socrates is more certain from induction than it is from deduction [Russell] |
| 11033 | Predications of predicates are predications of their subjects [Aristotle] |
| 5395 | Demonstration always relies on the rule that anything implied by a truth is true [Russell] |
| 5386 | Proper names are really descriptions, and can be replaced by a description in a person's mind [Russell] |
| 5385 | The phrase 'a so-and-so' is an 'ambiguous' description'; 'the so-and-so' (singular) is a 'definite' description [Russell] |
| 11044 | One is prior to two, because its existence is implied by two [Aristotle] |
| 11042 | Parts of a line join at a point, so it is continuous [Aristotle] |
| 11041 | Some quantities are discrete, like number, and others continuous, like lines, time and space [Aristotle] |
| 5399 | Maths is not known by induction, because further instances are not needed to support it [Russell] |
| 11286 | Primary being must be more than mere indeterminate ultimate subject of predication [Politis on Aristotle] |
| 1700 | There are six kinds of change: generation, destruction, increase, diminution, alteration, change of place [Aristotle] |
| 1699 | A thing is prior to another if it implies its existence [Aristotle] |
| 18366 | Of interdependent things, the prior one causes the other's existence [Aristotle] |
| 5370 | Space is neutral between touch and sight, so it cannot really be either of them [Russell] |
| 5418 | In a world of mere matter there might be 'facts', but no truths [Russell] |
| 11035 | There are ten basic categories for thinking about things [Aristotle] |
| 3311 | The categories (substance, quality, quantity, relation, action, passion, place, time) peter out inconsequentially [Benardete,JA on Aristotle] |
| 13121 | Substance,Quantity,Quality,Relation,Place,Time,Being-in-a-position,Having,Doing,Being affected [Aristotle, by Westerhoff] |
| 16116 | Aristotle derived categories as answers to basic questions about nature, size, quality, location etc. [Aristotle, by Gill,ML] |
| 21345 | Aristotle said relations are not substances, so (if they exist) they must be accidents [Aristotle, by Heil] |
| 5371 | Because we depend on correspondence, we know relations better than we know the items that relate [Russell] |
| 5407 | That Edinburgh is north of London is a non-mental fact, so relations are independent universals [Russell] |
| 16155 | Aristotle promoted the importance of properties and objects (rather than general and particular) [Aristotle, by Frede,M] |
| 11032 | Some things said 'of' a subject are not 'in' the subject [Aristotle] |
| 11038 | We call them secondary 'substances' because they reveal the primary substances [Aristotle] |
| 16739 | Four species of quality: states, capacities, affects, and forms [Aristotle, by Pasnau] |
| 18439 | Because things can share attributes, we cannot individuate attributes clearly [Quine] |
| 5383 | Every complete sentence must contain at least one word (a verb) which stands for a universal [Russell] |
| 4428 | Propositions express relations (prepositions and verbs) as well as properties (nouns and adjectives) [Russell] |
| 5406 | Confused views of reality result from thinking that only nouns and adjectives represent universals [Russell] |
| 4479 | All universals are like the relation "is north of", in having no physical location at all [Russell, by Loux] |
| 4030 | Russell claims that universals are needed to explain a priori knowledge (as their relations) [Russell, by Mellor/Oliver] |
| 4427 | Every sentence contains at least one word denoting a universal, so we need universals to know truth [Russell] |
| 11037 | Colour must be in an individual body, or it is not embodied [Aristotle] |
| 5409 | Normal existence is in time, so we must say that universals 'subsist' [Russell] |
| 5408 | If we identify whiteness with a thought, we can never think of it twice; whiteness is the object of a thought [Russell] |
| 4441 | 'Resemblance Nominalism' won't work, because the theory treats resemblance itself as a universal [Russell] |
| 4429 | If we consider whiteness to be merely a mental 'idea', we rob it of its universality [Russell] |
| 18442 | You only know an attribute if you know what things have it [Quine] |
| 16154 | Aristotle gave up his earlier notion of individuals, because it relied on universals [Aristotle, by Frede,M] |
| 18441 | No entity without identity (which requires a principle of individuation) [Quine] |
| 12351 | Genus and species are substances, because only they reveal the primary substance [Aristotle, by Wedin] |
| 11040 | A single substance can receive contrary properties [Aristotle] |
| 1694 | Substances have no opposites, and don't come in degrees (including if the substance is a man) [Aristotle] |
| 16091 | Is primary substance just an ultimate subject, or some aspect of a complex body? [Aristotle, by Gill,ML] |
| 11280 | Primary being is 'that which lies under', or 'particular substance' [Aristotle, by Politis] |
| 11036 | A 'primary' substance is in each subject, with species or genera as 'secondary' substances [Aristotle] |
| 16140 | Secondary substances do have subjects, so they are not ultimate in the ontology [Aristotle, by Frede,M] |
| 10965 | In earlier Aristotle the substances were particulars, not kinds [Aristotle, by Lawson-Tancred] |
| 8287 | Earlier Aristotle had objects as primary substances, but later he switched to substantial form [Aristotle, by Lowe] |
| 12350 | Things are called 'substances' because they are subjects for everything else [Aristotle] |
| 11039 | A primary substance reveals a 'this', which is an individual unit [Aristotle] |
| 12361 | Primary substances are ontological in 'Categories', and explanatory in 'Metaphysics' [Aristotle, by Wedin] |
| 3315 | Aristotle denigrates the category of relation, but for modern absolutists self-relation is basic [Benardete,JA on Aristotle] |
| 18440 | Identity of physical objects is just being coextensive [Quine] |
| 5400 | In any possible world we feel that two and two would be four [Russell] |
| 5431 | Knowledge cannot be precisely defined, as it merges into 'probable opinion' [Russell] |
| 5426 | Belief relates a mind to several things other than itself [Russell] |
| 5366 | We have an 'instinctive' belief in the external world, prior to all reflection [Russell] |
| 5359 | Descartes showed that subjective things are the most certain [Russell] |
| 5377 | 'Acquaintance' is direct awareness, without inferences or judgements [Russell] |
| 6510 | Russell (1912) said phenomena only resemble reality in abstract structure [Russell, by Robinson,H] |
| 5372 | There is no reason to think that objects have colours [Russell] |
| 5373 | 'Idealism' says that everything which exists is in some sense mental [Russell] |
| 5362 | It is not illogical to think that only myself and my mental events exist [Russell] |
| 5412 | Some propositions are self-evident, but their implications may also be self-evident [Russell] |
| 5413 | Particular instances are more clearly self-evident than any general principles [Russell] |
| 5415 | As shown by memory, self-evidence comes in degrees [Russell] |
| 5416 | If self-evidence has degrees, we should accept the more self-evident as correct [Russell] |
| 5397 | The rationalists were right, because we know logical principles without experience [Russell] |
| 4430 | All a priori knowledge deals with the relations of universals [Russell] |
| 5411 | We can know some general propositions by universals, when no instance can be given [Russell] |
| 6514 | Russell's representationalism says primary qualities only show the structure of reality [Russell, by Robinson,H] |
| 6415 | After 1912, Russell said sense-data are last in analysis, not first in experience [Russell, by Grayling] |
| 5358 | 'Sense-data' are what are immediately known in sensation, such as colours or roughnesses [Russell] |
| 7290 | If Russell rejects innate ideas and direct a priori knowledge, he is left with a tabula rasa [Russell, by Thompson] |
| 5357 | It is natural to begin from experience, and presumably that is the basis of knowledge [Russell] |
| 5382 | We are acquainted with outer and inner sensation, memory, Self, and universals [Russell, by PG] |
| 5389 | Knowledge by descriptions enables us to transcend private experience [Russell] |
| 5376 | I can know the existence of something with which nobody is acquainted [Russell] |
| 5414 | Images are not memory, because they are present, and memories are of the past [Russell] |
| 5430 | A true belief is not knowledge if it is reached by bad reasoning [Russell] |
| 5429 | True belief is not knowledge when it is deduced from false belief [Russell] |
| 5378 | All knowledge (of things and of truths) rests on the foundations of acquaintance [Russell] |
| 5365 | Dreams can be explained fairly scientifically if we assume a physical world [Russell] |
| 5391 | Science aims to find uniformities to which (within the limits of experience) there are no exceptions [Russell] |
| 5390 | Chickens are not very good at induction, and are surprised when their feeder wrings their neck [Russell] |
| 5394 | We can't prove induction from experience without begging the question [Russell] |
| 5392 | It doesn't follow that because the future has always resembled the past, that it always will [Russell] |
| 5363 | If the cat reappears in a new position, presumably it has passed through the intermediate positions [Russell] |
| 5367 | Belief in real objects makes our account of experience simpler and more systematic [Russell] |
| 5364 | It is hard not to believe that speaking humans are expressing thoughts, just as we do ourselves [Russell] |
| 5379 | If we didn't know our own minds by introspection, we couldn't know that other people have minds [Russell] |
| 5410 | I learn the universal 'resemblance' by seeing two shades of green, and their contrast with red [Russell] |
| 5381 | In seeing the sun, we are acquainted with our self, but not as a permanent person [Russell] |
| 5380 | In perceiving the sun, I am aware of sun sense-data, and of the perceiver of the data [Russell] |
| 5369 | It is rational to believe in reality, despite the lack of demonstrative reasons for it [Russell] |
| 5375 | Knowledge of truths applies to judgements; knowledge by acquaintance applies to sensations and things [Russell] |
| 21711 | Russell's 'multiple relations' theory says beliefs attach to ingredients, not to propositions [Russell, by Linsky,B] |
| 5427 | Truth is when a mental state corresponds to a complex unity of external constituents [Russell] |
| 5425 | In order to explain falsehood, a belief must involve several terms, not two [Russell] |
| 5384 | A universal of which we are aware is called a 'concept' [Russell] |
| 13468 | Russell started philosophy of language, by declaring some plausible sentences to be meaningless [Russell, by Hart,WD] |
| 5388 | Every understood proposition is composed of constituents with which we are acquainted [Russell] |
| 5387 | It is pure chance which descriptions in a person's mind make a name apply to an individual [Russell] |
| 12349 | Only what can be said of many things is a predicable [Aristotle, by Wedin] |
| 11837 | Some predicates signify qualification of a substance, others the substance itself [Aristotle] |
| 21724 | The main aim of the multiple relations theory of judgement was to dispense with propositions [Russell, by Linsky,B] |
| 5398 | Judgements of usefulness depend on judgements of value [Russell] |
| 11043 | It is not possible for fire to be cold or snow black [Aristotle] |
| 5393 | We can't know that our laws are exceptionless, or even that there are any laws [Russell] |
| 1696 | Change goes from possession to loss (as in baldness), but not the other way round [Aristotle] |