31 ideas
10859 | A set is 'well-ordered' if every subset has a first element [Clegg] |
10857 | Set theory made a closer study of infinity possible [Clegg] |
10864 | Any set can always generate a larger set - its powerset, of subsets [Clegg] |
10872 | Extensionality: Two sets are equal if and only if they have the same elements [Clegg] |
10875 | Pairing: For any two sets there exists a set to which they both belong [Clegg] |
10876 | Unions: There is a set of all the elements which belong to at least one set in a collection [Clegg] |
10878 | Infinity: There exists a set of the empty set and the successor of each element [Clegg] |
10877 | Powers: All the subsets of a given set form their own new powerset [Clegg] |
10879 | Choice: For every set a mechanism will choose one member of any non-empty subset [Clegg] |
10871 | Axiom of Existence: there exists at least one set [Clegg] |
10874 | Specification: a condition applied to a set will always produce a new set [Clegg] |
10880 | Mathematics can be 'pure' (unapplied), 'real' (physically grounded); or 'applied' (just applicable) [Clegg] |
10861 | Beyond infinity cardinals and ordinals can come apart [Clegg] |
10860 | An ordinal number is defined by the set that comes before it [Clegg] |
10854 | Transcendental numbers can't be fitted to finite equations [Clegg] |
10858 | By adding an axis of imaginary numbers, we get the useful 'number plane' instead of number line [Clegg] |
10853 | Either lack of zero made early mathematics geometrical, or the geometrical approach made zero meaningless [Clegg] |
10866 | Cantor's account of infinities has the shaky foundation of irrational numbers [Clegg] |
10869 | The Continuum Hypothesis is independent of the axioms of set theory [Clegg] |
10862 | The 'continuum hypothesis' says aleph-one is the cardinality of the reals [Clegg] |
23634 | Accepting the existence of anything presupposes the notion of existence [Reid] |
23635 | Truths are self-evident to sensible persons who understand them clearly without prejudice [Reid] |
7631 | Sensation is not committed to any external object, but perception is [Reid] |
23637 | Primary qualities are the object of mathematics [Reid] |
23638 | Secondary qualities conjure up, and are confused with, the sensations which produce them [Reid] |
23639 | It is unclear whether a toothache is in the mind or in the tooth, but the word has a single meaning [Reid] |
6492 | Reid is seen as the main direct realist of the eighteenth century [Reid, by Robinson,H] |
23641 | People dislike believing without evidence, and try to avoid it [Reid] |
23642 | If non-rational evidence reaches us, it is reason which then makes use of it [Reid] |
23640 | Only mature minds can distinguish the qualities of a body [Reid] |
4800 | Natural laws result from eliminative induction, where enumerative induction gives generalisations [Cohen,LJ, by Psillos] |