28 ideas
8952 | We reach 'reflective equilibrium' when intuitions and theory completely align [Fisher] |
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] |
8943 | Three-valued logic says excluded middle and non-contradition are not tautologies [Fisher] |
8945 | Fuzzy logic has many truth values, ranging in fractions from 0 to 1 [Fisher] |
8951 | Classical logic is: excluded middle, non-contradiction, contradictions imply all, disjunctive syllogism [Fisher] |
7789 | Necessary implication is called 'strict implication'; if successful, it is called 'entailment' [Girle] |
8950 | Logic formalizes how we should reason, but it shouldn't determine whether we are realists [Fisher] |
7790 | If an argument is invalid, a truth tree will indicate a counter-example [Girle] |
8203 | All the arithmetical entities can be reduced to classes of integers, and hence to sets [Quine] |
8946 | We could make our intuitions about heaps precise with a million-valued logic [Fisher] |
8944 | Vagueness can involve components (like baldness), or not (like boredom) [Fisher] |
7800 | Analytic truths are divided into logically and conceptually necessary [Girle] |
7801 | Possibilities can be logical, theoretical, physical, economic or human [Girle] |
8941 | We can't explain 'possibility' in terms of 'possible' worlds [Fisher] |
8947 | If all truths are implied by a falsehood, then not-p might imply both q and not-q [Fisher] |
8949 | In relevance logic, conditionals help information to flow from antecedent to consequent [Fisher] |
7792 | A world has 'access' to a world it generates, which is important in possible worlds semantics [Girle] |
8202 | Meaning is essence divorced from things and wedded to words [Quine] |
8201 | The distinction between meaning and further information is as vague as the essence/accident distinction [Quine] |