24 ideas
7910 | Pursue truth with the urgency of someone whose clothes are on fire [Ashvaghosha] |
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] |
6417 | In 1921 Russell abandoned sense-data, and the gap between sensation and object [Russell, by Grayling] |
6474 | Seeing is not in itself knowledge, but is separate from what is seen, such as a patch of colour [Russell] |
6476 | We cannot assume that the subject actually exists, so we cannot distinguish sensations from sense-data [Russell] |
2792 | It is possible the world came into existence five minutes ago, complete with false memories [Russell] |
22326 | Knowledge needs more than a sensitive response; the response must also be appropriate [Russell] |
6475 | In perception, the self is just a logical fiction demanded by grammar [Russell] |
7909 | The Eightfold Path concerns morality, wisdom, and tranquillity [Ashvaghosha] |
7908 | At the end of a saint, he is not located in space, but just ceases to be disturbed [Ashvaghosha] |