23 ideas
9198 | It is no longer possible to be a sage, but we can practice the exercise of wisdom [Hadot] |
9197 | The logos represents a demand for universal rationality [Hadot] |
7798 | There are three axiom schemas for propositional logic [Girle] |
7786 | Propositional logic handles negation, disjunction, conjunction; predicate logic adds quantifiers, predicates, relations [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] |
7796 | Modal logics were studied in terms of axioms, but now possible worlds semantics is added [Girle] |
7788 | Modal logic has four basic modal negation equivalences [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] |
22392 | Morality is inescapable, in descriptive words such as 'dishonest', 'unjust' and 'uncharitable' [Foot] |
23685 | Reason is not a motivator of morality [Foot, by Hacker-Wright] |
23691 | Rejecting moral rules may be villainous, but it isn't inconsistent [Foot] |
9196 | The pleasure of existing is the only genuine pleasure [Hadot] |
22391 | Saying we 'ought to be moral' makes no sense, unless it relates to some other system [Foot] |
22389 | Morality no more consists of categorical imperatives than etiquette does [Foot] |