24 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] |
15201 | That Queen Anne is dead is a 'general fact', not a fact about Queen Anne [Prior,AN] |
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] |
6479 | Noninterference requires justification as much as interference does [Nagel] |
6450 | Morality must be motivating, and not because of pre-moral motives [Nagel] |
6447 | Game theory misses out the motivation arising from the impersonal standpoint [Nagel] |
6446 | In ethics we abstract from our identity, but not from our humanity [Nagel] |
6477 | I can only universalise a maxim if everyone else could also universalise it [Nagel] |
6448 | A legitimate system is one accepted as both impartial and reasonably partial [Nagel] |
6478 | Democracy is opposed to equality, if the poor are not a majority [Nagel] |
22899 | 'Thank goodness that's over' is not like 'thank goodness that happened on Friday' [Prior,AN] |