23 ideas
18781 | Inconsistency doesn't prevent us reasoning about some system [Mares] |
21918 | Sufficient Reason can't be proved, because all proof presupposes it [Schopenhauer, by Lewis,PB] |
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] |
21920 | No need for a priori categories, since sufficient reason shows the interrelations [Schopenhauer, by Lewis,PB] |
21362 | Necessity is physical, logical, mathematical or moral [Schopenhauer, by Janaway] |
21361 | For Schopenhauer, material things would not exist without the mind [Schopenhauer, by Janaway] |
21919 | Object for a subject and representation are the same thing [Schopenhauer] |
21917 | The four explanations: objects by causes, concepts by ground, maths by spacetime, ethics by motive [Schopenhauer, by Lewis,PB] |
21921 | Concepts are abstracted from perceptions [Schopenhauer, by Lewis,PB] |
18791 | In 'situation semantics' our main concepts are abstracted from situations [Mares] |
21363 | Motivation is causality seen from within [Schopenhauer] |
7482 | Resurrection developed in Judaism as a response to martyrdoms, in about 160 BCE [Anon (Dan), by Watson] |