23 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] |
14775 | Numbers are just names devised for counting [Peirce] |
14776 | That two two-eyed people must have four eyes is a statement about numbers, not a fact [Peirce] |
18788 | For intuitionists there are not numbers and sets, but processes of counting and collecting [Mares] |
14770 | Reasoning is based on statistical induction, so it can't achieve certainty or precision [Peirce] |
14774 | Innate truths are very uncertain and full of error, so they certainly have exceptions [Peirce] |
14773 | A truth is hard for us to understand if it rests on nothing but inspiration [Peirce] |
14772 | If we decide an idea is inspired, we still can't be sure we have got the idea right [Peirce] |
14771 | Only reason can establish whether some deliverance of revelation really is inspired [Peirce] |
14769 | Only imagination can connect phenomena together in a rational way [Peirce] |
18791 | In 'situation semantics' our main concepts are abstracted from situations [Mares] |
468 | Musical performance can reveal a range of virtues [Damon of Ath.] |