30 ideas
| 22496 | Wisdom only implies the knowledge achievable in any normal lifetime [Foot] |
| 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] |
| 23694 | All criterions of practical rationality derive from goodness of will [Foot] |
| 23686 | Moral reason is not just neutral, because morality is part of the standard of rationality [Foot, by Hacker-Wright] |
| 23693 | Practical rationality must weigh both what is morally and what is non-morally required [Foot] |
| 23687 | Moral virtues arise from human nature, as part of what makes us good human beings [Foot, by Hacker-Wright] |
| 22493 | Sterility is a human defect, but the choice to be childless is not [Foot] |
| 22492 | Virtues are as necessary to humans as stings are to bees [Foot] |
| 22491 | Moral evaluations are not separate from facts, but concern particular facts about functioning [Foot] |
| 22497 | Deep happiness usually comes from the basic things in life [Foot] |
| 22498 | Happiness is enjoying the pursuit and attainment of right ends [Foot] |
| 23695 | Good actions can never be justified by the good they brings to their agent [Foot] |
| 22499 | We all know that just pretending to be someone's friend is not the good life [Foot] |
| 22495 | Someone is a good person because of their rational will, not their body or memory [Foot] |
| 22502 | Refraining from murder is not made good by authenticity or self-fulfilment [Foot] |
| 20543 | 'Social justice' is a confused idea, and inequalities need no justification [Hayek, by Swift] |