34 ideas
18781 | Inconsistency doesn't prevent us reasoning about some system [Mares] |
18789 | Intuitionist logic looks best as natural deduction [Mares] |
18790 | Intuitionism as natural deduction has no rule for negation [Mares] |
18787 | Three-valued logic is useful for a theory of presupposition [Mares] |
18793 | Material implication (and classical logic) considers nothing but truth values for implications [Mares] |
18784 | In classical logic the connectives can be related elegantly, as in De Morgan's laws [Mares] |
18786 | Excluded middle standardly implies bivalence; attacks use non-contradiction, De M 3, or double negation [Mares] |
18780 | Standard disjunction and negation force us to accept the principle of bivalence [Mares] |
18782 | The connectives are studied either through model theory or through proof theory [Mares] |
18783 | Many-valued logics lack a natural deduction system [Mares] |
18792 | Situation semantics for logics: not possible worlds, but information in situations [Mares] |
18785 | Consistency is semantic, but non-contradiction is syntactic [Mares] |
18788 | For intuitionists there are not numbers and sets, but processes of counting and collecting [Mares] |
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] |
11905 | Locke's kind essences are explanatory, without being necessary to the kind [Mackie,P] |
18791 | In 'situation semantics' our main concepts are abstracted from situations [Mares] |
13304 | Learned men gain more in one day than others do in a lifetime [Posidonius] |
11907 | Maybe the identity of kinds is necessary, but instances being of that kind is not [Mackie,P] |
20820 | Time is an interval of motion, or the measure of speed [Posidonius, by Stobaeus] |