105 ideas
12926 | Wisdom is the science of happiness [Leibniz] |
12903 | Wise people have fewer acts of will, because such acts are linked together [Leibniz] |
12914 | Metaphysics is geometrical, resting on non-contradiction and sufficient reason [Leibniz] |
11159 | My account shows how the concept works, rather than giving an analysis [Fine,K] |
11157 | Modern philosophy has largely abandoned real definitions, apart from sortals [Fine,K] |
12915 | Definitions can only be real if the item is possible [Leibniz] |
11171 | Defining a term and giving the essence of an object don't just resemble - they are the same [Fine,K] |
19333 | A truth is just a proposition in which the predicate is contained within the subject [Leibniz] |
12910 | The predicate is in the subject of a true proposition [Leibniz] |
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] |
10865 | The continuum is the powerset of the integers, which moves up a level [Cantor, by Clegg] |
10701 | Cantor showed that supposed contradictions in infinity were just a lack of clarity [Cantor, by Potter] |
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] |
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] |
12920 | There is no multiplicity without true units [Leibniz] |
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] |
17889 | CH: An infinite set of reals corresponds 1-1 either to the naturals or to the reals [Cantor, by Koellner] |
8733 | The Continuum Hypothesis says there are no sets between the natural numbers and reals [Cantor, by Shapiro] |
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] |
12319 | What is not truly one being is not truly a being either [Leibniz] |
11151 | An object is dependent if its essence prevents it from existing without some other object [Fine,K] |
12922 | A thing 'expresses' another if they have a constant and fixed relationship [Leibniz] |
13079 | A substance contains the laws of its operations, and its actions come from its own depth [Leibniz] |
12745 | Philosophy needs the precision of the unity given by substances [Leibniz] |
12921 | Accidental unity has degrees, from a mob to a society to a machine or organism [Leibniz] |
12746 | We find unity in reason, and unity in perception, but these are not true unity [Leibniz] |
12916 | A body is a unified aggregate, unless it has an indivisible substance [Leibniz] |
12919 | Unity needs an indestructible substance, to contain everything which will happen to it [Leibniz] |
12923 | Every bodily substance must have a soul, or something analogous to a soul [Leibniz] |
12704 | Aggregates don’t reduce to points, or atoms, or illusion, so must reduce to substance [Leibniz] |
13077 | Basic predicates give the complete concept, which then predicts all of the actions [Leibniz] |
12908 | Essences exist in the divine understanding [Leibniz] |
11152 | Essences are either taken as real definitions, or as necessary properties [Fine,K] |
12706 | Bodies need a soul (or something like it) to avoid being mere phenomena [Leibniz] |
11161 | Essentially having a property is naturally expressed as 'the property it must have to be what it is' [Fine,K] |
11160 | Simple modal essentialism refers to necessary properties of an object [Fine,K] |
11158 | Essentialist claims can be formulated more clearly with quantified modal logic [Fine,K] |
11167 | Metaphysical necessity is a special case of essence, not vice versa [Fine,K] |
16537 | Essence as necessary properties produces a profusion of essential properties [Fine,K, by Lowe] |
11163 | The nature of singleton Socrates has him as a member, but not vice versa [Fine,K] |
11164 | It is not part of the essence of Socrates that a huge array of necessary truths should hold [Fine,K] |
10935 | An essential property of something must be bound up with what it is to be that thing [Fine,K, by Rami] |
10936 | Essential properties are part of an object's 'definition' [Fine,K, by Rami] |
12906 | Truths about species are eternal or necessary, but individual truths concern what exists [Leibniz] |
11165 | If Socrates lacks necessary existence, then his nature cannot require his parents' existence [Fine,K] |
11166 | The subject of a proposition need not be the source of its necessity [Fine,K] |
11169 | Conceptual necessities rest on the nature of all concepts [Fine,K] |
11162 | Socrates is necessarily distinct from the Eiffel Tower, but that is not part of his essence [Fine,K] |
11168 | Metaphysical necessities are true in virtue of the nature of all objects [Fine,K] |
12904 | If varieties of myself can be conceived of as distinct from me, then they are not me [Leibniz] |
11981 | If someone's life went differently, then that would be another individual [Leibniz] |
12905 | I cannot think my non-existence, nor exist without being myself [Leibniz] |
19334 | I can't just know myself to be a substance; I must distinguish myself from others, which is hard [Leibniz] |
5033 | Nothing should be taken as certain without foundations [Leibniz] |
12913 | Nature is explained by mathematics and mechanism, but the laws rest on metaphysics [Leibniz] |
13089 | To fully conceive the subject is to explain the resulting predicates and events [Leibniz] |
5034 | Mind is a thinking substance which can know God and eternal truths [Leibniz] |
5032 | It seems probable that animals have souls, but not consciousness [Leibniz] |
5031 | Everything which happens is not necessary, but is certain after God chooses this universe [Leibniz] |
12911 | Concepts are what unite a proposition [Leibniz] |
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] |
11172 | The meaning of 'bachelor' is irrelevant to the meaning of 'unmarried man' [Fine,K] |
11170 | Analytic truth may only be true in virtue of the meanings of certain terms [Fine,K] |
12925 | Beauty increases with familiarity [Leibniz] |
12927 | Happiness is advancement towards perfection [Leibniz] |
15955 | I think the corpuscular theory, rather than forms or qualities, best explains particular phenomena [Leibniz] |
12907 | Each possible world contains its own laws, reflected in the possible individuals of that world [Leibniz] |
12924 | Motion alone is relative, but force is real, and establishes its subject [Leibniz] |
10863 | Cantor proved that three dimensions have the same number of points as one dimension [Cantor, by Clegg] |
13465 | Only God is absolutely infinite [Cantor, by Hart,WD] |
12909 | Everything, even miracles, belongs to order [Leibniz] |
5030 | Miracles are extraordinary operations by God, but are nevertheless part of his design [Leibniz] |
12912 | Immortality without memory is useless [Leibniz] |
12917 | The soul is indestructible and always self-aware [Leibniz] |
12918 | Animals have souls, but lack consciousness [Leibniz] |