97 ideas
| 24047 | An account is either a definition or a demonstration [Aristotle] |
| 24052 | From one thing alone we can infer its contrary [Aristotle] |
| 15901 | Trying to represent curves, we study arbitrary functions, leading to the ordinals, which produces set theory [Cantor, by Lavine] |
| 13444 | Cantor's Theorem: for any set x, its power set P(x) has more members than x [Cantor, by Hart,WD] |
| 18098 | Cantor proved that all sets have more subsets than they have members [Cantor, by Bostock] |
| 15505 | If a set is 'a many thought of as one', beginners should protest against singleton sets [Cantor, by Lewis] |
| 10701 | Cantor showed that supposed contradictions in infinity were just a lack of clarity [Cantor, by Potter] |
| 10865 | The continuum is the powerset of the integers, which moves up a level [Cantor, by Clegg] |
| 13016 | The Axiom of Union dates from 1899, and seems fairly obvious [Cantor, by Maddy] |
| 14199 | Cantor's sets were just collections, but Dedekind's were containers [Cantor, by Oliver/Smiley] |
| 10082 | There are infinite sets that are not enumerable [Cantor, by Smith,P] |
| 13483 | Cantor's Paradox: the power set of the universe must be bigger than the universe, yet a subset of it [Cantor, by Hart,WD] |
| 8710 | The powerset of all the cardinal numbers is required to be greater than itself [Cantor, by Friend] |
| 15910 | Cantor named the third realm between the finite and the Absolute the 'transfinite' [Cantor, by Lavine] |
| 1729 | We perceive number by the denial of continuity [Aristotle] |
| 15905 | Cantor proved the points on a plane are in one-to-one correspondence to the points on a line [Cantor, by Lavine] |
| 9983 | Cantor took the ordinal numbers to be primary [Cantor, by Tait] |
| 17798 | Cantor presented the totality of natural numbers as finite, not infinite [Cantor, by Mayberry] |
| 9971 | Cantor introduced the distinction between cardinals and ordinals [Cantor, by Tait] |
| 9892 | Cantor showed that ordinals are more basic than cardinals [Cantor, by Dummett] |
| 14136 | A cardinal is an abstraction, from the nature of a set's elements, and from their order [Cantor] |
| 15906 | Cantor tried to prove points on a line matched naturals or reals - but nothing in between [Cantor, by Lavine] |
| 11015 | Cantor's diagonal argument proved you can't list all decimal numbers between 0 and 1 [Cantor, by Read] |
| 15903 | A real is associated with an infinite set of infinite Cauchy sequences of rationals [Cantor, by Lavine] |
| 18251 | Irrational numbers are the limits of Cauchy sequences of rational numbers [Cantor, by Lavine] |
| 15902 | Irrationals and the Dedekind Cut implied infinite classes, but they seemed to have logical difficulties [Cantor, by Lavine] |
| 15908 | It was Cantor's diagonal argument which revealed infinities greater than that of the real numbers [Cantor, by Lavine] |
| 13464 | Cantor proposes that there won't be a potential infinity if there is no actual infinity [Cantor, by Hart,WD] |
| 10112 | The naturals won't map onto the reals, so there are different sizes of infinity [Cantor, by George/Velleman] |
| 8733 | The Continuum Hypothesis says there are no sets between the natural numbers and reals [Cantor, by Shapiro] |
| 17889 | CH: An infinite set of reals corresponds 1-1 either to the naturals or to the reals [Cantor, by Koellner] |
| 13447 | Cantor: there is no size between naturals and reals, or between a set and its power set [Cantor, by Hart,WD] |
| 10883 | Cantor's Continuum Hypothesis says there is a gap between the natural and the real numbers [Cantor, by Horsten] |
| 13528 | Continuum Hypothesis: there are no sets between N and P(N) [Cantor, by Wolf,RS] |
| 9555 | Continuum Hypothesis: no cardinal greater than aleph-null but less than cardinality of the continuum [Cantor, by Chihara] |
| 18174 | Cantor extended ordinals into the transfinite, and they can thus measure infinite cardinalities [Cantor, by Maddy] |
| 15893 | Cantor's theory concerns collections which can be counted, using the ordinals [Cantor, by Lavine] |
| 18173 | Cardinality strictly concerns one-one correspondence, to test infinite sameness of size [Cantor, by Maddy] |
| 10232 | Property extensions outstrip objects, so shortage of objects caused the Caesar problem [Cantor, by Shapiro] |
| 18176 | Pure mathematics is pure set theory [Cantor] |
| 8631 | Cantor says that maths originates only by abstraction from objects [Cantor, by Frege] |
| 24057 | What is prior is always potentially present in what is next in order [Aristotle] |
| 16752 | Sight is the essence of the eye, fitting its definition; the eye itself is just the matter [Aristotle] |
| 24058 | The substance is the cause of a thing's being [Aristotle] |
| 24055 | Matter is potential, form is actual [Aristotle] |
| 24040 | Scientists explain anger by the matter, dialecticians by the form and the account [Aristotle] |
| 5051 | The intellect has potential to think, like a tablet on which nothing has yet been written [Aristotle] |
| 16723 | Perception of sensible objects is virtually never wrong [Aristotle] |
| 1724 | Perception necessitates pleasure and pain, which necessitates appetite [Aristotle] |
| 1730 | Why do we have many senses, and not just one? [Aristotle] |
| 17711 | Our minds take on the form of what is being perceived [Aristotle, by Mares] |
| 1725 | Why can't we sense the senses? And why do senses need stimuli? [Aristotle] |
| 1732 | Sense organs aren't the end of sensation, or they would know what does the sensing [Aristotle] |
| 1728 | Many objects of sensation are common to all the senses [Aristotle] |
| 1727 | Some objects of sensation are unique to one sense, where deception is impossible [Aristotle] |
| 1734 | In moral thought images are essential, to be pursued or avoided [Aristotle] |
| 1726 | We may think when we wish, but not perceive, because universals are within the mind [Aristotle] |
| 16647 | Demonstration starts from a definition of essence, so we can derive (or conjecture about) the properties [Aristotle] |
| 24048 | Demonstrations move from starting-points to deduced conclusions [Aristotle] |
| 16646 | To understand a triangle summing to two right angles, we need to know the essence of a line [Aristotle] |
| 1714 | Mind involves movement, perception, incorporeality [Aristotle] |
| 5507 | Aristotle led to the view that there are several souls, all somewhat physical [Aristotle, by Martin/Barresi] |
| 24051 | Soul is seen as what moves, or what is least physical, or a combination of elements [Aristotle] |
| 12086 | Psuché is the form and actuality of a body which potentially has life [Aristotle] |
| 16754 | The soul is the cause or source of movement, the essence of body, and its end [Aristotle] |
| 24046 | Understanding is impossible, if it involves the understanding having parts [Aristotle] |
| 1717 | If the soul is composed of many physical parts, it can't be a true unity [Aristotle] |
| 24053 | If a soul have parts, what unites them? [Aristotle] |
| 1721 | What unifies the soul would have to be a super-soul, which seems absurd [Aristotle] |
| 1735 | In a way the soul is everything which exists, through its perceptions and thoughts [Aristotle] |
| 24061 | If we divide the mind up according to its capacities, there are a lot of them [Aristotle] |
| 24062 | Self-moving animals must have desires, and that entails having imagination [Aristotle] |
| 1710 | Emotion involves the body, thinking uses the mind, imagination hovers between them [Aristotle] |
| 24056 | The soul (or parts of it) is not separable from the body [Aristotle] |
| 24039 | All the emotions seem to involve the body, simultaneously with the feeling [Aristotle] |
| 24050 | If soul is separate from body, why does it die when the body dies? [Aristotle] |
| 24049 | Thinkers place the soul within the body, but never explain how they are attached [Aristotle] |
| 1514 | Early thinkers concentrate on the soul but ignore the body, as if it didn't matter what body received the soul [Aristotle] |
| 2683 | Aristotle has a problem fitting his separate reason into the soul, which is said to be the form of the body [Ackrill on Aristotle] |
| 1718 | Does the mind think or pity, or does the whole man do these things? [Aristotle] |
| 13275 | The soul and the body are inseparable, like the imprint in some wax [Aristotle] |
| 1733 | Thinking is not perceiving, but takes the form of imagination and speculation [Aristotle] |
| 23307 | Aristotle makes belief a part of reason, but sees desires as separate [Aristotle, by Sorabji] |
| 8715 | Infinities expand the bounds of the conceivable; we explore concepts to explore conceivability [Cantor, by Friend] |
| 13454 | Cantor says (vaguely) that we abstract numbers from equal sized sets [Hart,WD on Cantor] |
| 18033 | The meaning of a representation is its role in thought, perception or decisions [Block] |
| 24060 | Self-controlled follow understanding, when it is opposed to desires [Aristotle] |
| 4376 | Pleasure and pain are perceptions of things as good or bad [Aristotle] |
| 1740 | Nature does nothing in vain [Aristotle] |
| 1739 | If all movement is either pushing or pulling, there must be a still point in between where it all starts [Aristotle] |
| 24045 | Movement is spatial, alteration, withering or growth [Aristotle] |
| 1738 | Practical reason is based on desire, so desire must be the ultimate producer of movement [Aristotle] |
| 24044 | Movement can be intrinsic (like a ship) or relative (like its sailors) [Aristotle] |
| 24064 | If something is pushed, it pushes back [Aristotle] |
| 10863 | Cantor proved that three dimensions have the same number of points as one dimension [Cantor, by Clegg] |
| 24063 | What is born has growth, a prime, and a withering away [Aristotle] |
| 13465 | Only God is absolutely infinite [Cantor, by Hart,WD] |