42 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] |
10482 | The logic of ZF is classical first-order predicate logic with identity [Boolos] |
10492 | A few axioms of set theory 'force themselves on us', but most of them don't [Boolos] |
10485 | Naïve sets are inconsistent: there is no set for things that do not belong to themselves [Boolos] |
10484 | The iterative conception says sets are formed at stages; some are 'earlier', and must be formed first [Boolos] |
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] |
10491 | Infinite natural numbers is as obvious as infinite sentences in English [Boolos] |
10483 | Mathematics and science do not require very high orders of infinity [Boolos] |
10490 | Mathematics isn't surprising, given that we experience many objects as abstract [Boolos] |
10488 | It is lunacy to think we only see ink-marks, and not word-types [Boolos] |
10487 | I am a fan of abstract objects, and confident of their existence [Boolos] |
10489 | We deal with abstract objects all the time: software, poems, mistakes, triangles.. [Boolos] |
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] |
3772 | The will, in the beginning, is entirely produced by desire [Mill] |
3769 | With early training, any absurdity or evil may be given the power of conscience [Mill] |
3767 | Motive shows the worth of the agent, but not of the action [Mill] |
3771 | Virtues only have value because they achieve some further end [Mill] |
3768 | Orthodox morality is the only one which feels obligatory [Mill] |
7202 | The English believe in the task of annihilating evil for the victory of good [Nietzsche on Mill] |
5935 | Mill's qualities of pleasure is an admission that there are other good states of mind than pleasure [Ross on Mill] |
3764 | Actions are right if they promote pleasure, wrong if they promote pain [Mill] |
3776 | Utilitarianism only works if everybody has a totally equal right to happiness [Mill] |
3765 | Only pleasure and freedom from pain are desirable as ends [Mill] |
3763 | Ultimate goods such as pleasure can never be proved to be good [Mill] |
3766 | Better to be Socrates dissatisfied than a fool satisfied [Mill] |
3770 | General happiness is only desirable because individuals desire their own happiness [Mill] |
6697 | Moral rules protecting human welfare are more vital than local maxims [Mill] |
3774 | Rights are a matter of justice, not of benevolence [Mill] |
3773 | No individual has the right to receive our benevolence [Mill] |
3775 | A right is a valid claim to society's protection [Mill] |