24 ideas
23881 | All thought about values is philosophical, and thought about anything else is not philosophy [Weil] |
23885 | Philosophy aims to change the soul, not to accumulate knowledge [Weil] |
23886 | Systems are not unique to each philosopher. The platonist tradition is old and continuous [Weil] |
18781 | Inconsistency doesn't prevent us reasoning about some system [Mares] |
23884 | Truth is a value of thought [Weil] |
18790 | Intuitionism as natural deduction has no rule for negation [Mares] |
18789 | Intuitionist logic looks best as natural deduction [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] |
23476 | Logical constants seem to be entities in propositions, but are actually pure form [Russell] |
23477 | We use logical notions, so they must be objects - but I don't know what they really are [Russell] |
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] |
18273 | Logical truths are known by their extreme generality [Russell] |
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] |
22315 | There can't be a negative of a complex, which is negated by its non-existence [Potter on Russell] |
18791 | In 'situation semantics' our main concepts are abstracted from situations [Mares] |
23882 | Ends, unlike means, cannot be defined, which is why people tend to pursue means [Weil] |
23883 | Minds essentially and always strive towards value [Weil] |