39 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] |
10860 | An ordinal number is defined by the set that comes before it [Clegg] |
10861 | Beyond infinity cardinals and ordinals can come apart [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] |
11897 | A principle of individuation may pinpoint identity and distinctness, now and over time [Mackie,P] |
11898 | Individuation may include counterfactual possibilities, as well as identity and persistence [Mackie,P] |
11883 | A haecceity is the essential, simple, unanalysable property of being-this-thing [Mackie,P] |
11889 | Essentialism must avoid both reduplication of essences, and multiple occupancy by essences [Mackie,P] |
11877 | An individual essence is the properties the object could not exist without [Mackie,P] |
11882 | No other object can possibly have the same individual essence as some object [Mackie,P] |
11886 | There are problems both with individual essences and without them [Mackie,P] |
11909 | Unlike Hesperus=Phosophorus, water=H2O needs further premisses before it is necessary [Mackie,P] |
11899 | Why are any sortals essential, and why are only some of them essential? [Mackie,P] |
11906 | The Kripke and Putnam view of kinds makes them explanatorily basic, but has modal implications [Mackie,P] |
11894 | Origin is not a necessity, it is just 'tenacious'; we keep it fixed in counterfactual discussions [Mackie,P] |
11887 | Transworld identity without individual essences leads to 'bare identities' [Mackie,P] |
11890 | De re modality without bare identities or individual essence needs counterparts [Mackie,P] |
11892 | Things may only be counterparts under some particular relation [Mackie,P] |
11893 | Possibilities for Caesar must be based on some phase of the real Caesar [Mackie,P] |
11884 | The theory of 'haecceitism' does not need commitment to individual haecceities [Mackie,P] |
3061 | Anaxarchus said that he was not even sure that he knew nothing [Anaxarchus, by Diog. Laertius] |
11905 | Locke's kind essences are explanatory, without being necessary to the kind [Mackie,P] |
11907 | Maybe the identity of kinds is necessary, but instances being of that kind is not [Mackie,P] |