25 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] |
9406 | A class is natural when everybody can spot further members of it [Quinton] |
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] |
15730 | Extreme nominalists say all classification is arbitrary convention [Quinton] |
15728 | The naturalness of a class depends as much on the observers as on the objects [Quinton] |
9407 | Properties imply natural classes which can be picked out by everybody [Quinton] |
15729 | Uninstantiated properties must be defined using the instantiated ones [Quinton] |
8520 | An individual is a union of a group of qualities and a position [Quinton, by Campbell,K] |
14759 | A thing is simply a long event, linked by qualities, and spatio-temporal unity [Broad] |
11842 | If short-lived happenings like car crashes are 'events', why not long-lived events like Dover Cliffs? [Broad] |
18791 | In 'situation semantics' our main concepts are abstracted from situations [Mares] |
8160 | The present and past exist, but the future does not [Broad, by Dummett] |
14609 | We could say present and past exist, but not future, so that each event adds to the total history [Broad] |
22933 | We imagine the present as a spotlight, moving across events from past to future [Broad] |