26 ideas
7786 | Propositional logic handles negation, disjunction, conjunction; predicate logic adds quantifiers, predicates, relations [Girle] |
7798 | There are three axiom schemas for propositional logic [Girle] |
7799 | Proposition logic has definitions for its three operators: or, and, and identical [Girle] |
7797 | Axiom systems of logic contain axioms, inference rules, and definitions of proof and theorems [Girle] |
7794 | There are seven modalities in S4, each with its negation [Girle] |
7793 | ◊p → □◊p is the hallmark of S5 [Girle] |
7795 | S5 has just six modalities, and all strings can be reduced to those [Girle] |
7787 | Possible worlds logics use true-in-a-world rather than true [Girle] |
7788 | Modal logic has four basic modal negation equivalences [Girle] |
7796 | Modal logics were studied in terms of axioms, but now possible worlds semantics is added [Girle] |
7789 | Necessary implication is called 'strict implication'; if successful, it is called 'entailment' [Girle] |
7790 | If an argument is invalid, a truth tree will indicate a counter-example [Girle] |
7800 | Analytic truths are divided into logically and conceptually necessary [Girle] |
7801 | Possibilities can be logical, theoretical, physical, economic or human [Girle] |
7792 | A world has 'access' to a world it generates, which is important in possible worlds semantics [Girle] |
19682 | Internalists are much more interested in evidence than externalists are [McGrew] |
19684 | Does spotting a new possibility count as evidence? [McGrew] |
19687 | Absence of evidence proves nothing, and weird claims need special evidence [McGrew] |
19688 | Every event is highly unlikely (in detail), but may be perfectly plausible [McGrew] |
19686 | Criminal law needs two separate witnesses, but historians will accept one witness [McGrew] |
19680 | Maybe all evidence consists of beliefs, rather than of facts [McGrew] |
19681 | If all evidence is propositional, what is the evidence for the proposition? Do we face a regress? [McGrew] |
19689 | Several unreliable witnesses can give good support, if they all say the same thing [McGrew] |
19683 | Narrow evidentialism relies wholly on propositions; the wider form includes other items [McGrew] |
19685 | Falsificationism would be naive if even a slight discrepancy in evidence killed a theory [McGrew] |
20653 | Six reduction levels: groups, lives, cells, molecules, atoms, particles [Putnam/Oppenheim, by Watson] |