52 ideas
23853 | Truth is not a object we love - it is the radiant manifestation of reality [Weil] |
9724 | Until the 1960s the only semantics was truth-tables [Enderton] |
9703 | 'dom R' indicates the 'domain' of objects having a relation [Enderton] |
9705 | 'fld R' indicates the 'field' of all objects in the relation [Enderton] |
9704 | 'ran R' indicates the 'range' of objects being related to [Enderton] |
9710 | We write F:A→B to indicate that A maps into B (the output of F on A is in B) [Enderton] |
9707 | 'F(x)' is the unique value which F assumes for a value of x [Enderton] |
9712 | A relation is 'symmetric' on a set if every ordered pair has the relation in both directions [Enderton] |
9713 | A relation is 'transitive' if it can be carried over from two ordered pairs to a third [Enderton] |
9699 | The 'powerset' of a set is all the subsets of a given set [Enderton] |
9700 | Two sets are 'disjoint' iff their intersection is empty [Enderton] |
9702 | A 'domain' of a relation is the set of members of ordered pairs in the relation [Enderton] |
9701 | A 'relation' is a set of ordered pairs [Enderton] |
9706 | A 'function' is a relation in which each object is related to just one other object [Enderton] |
9708 | A function 'maps A into B' if the relating things are set A, and the things related to are all in B [Enderton] |
9709 | A function 'maps A onto B' if the relating things are set A, and the things related to are set B [Enderton] |
9711 | A relation is 'reflexive' on a set if every member bears the relation to itself [Enderton] |
9714 | A relation satisfies 'trichotomy' if all pairs are either relations, or contain identical objects [Enderton] |
9717 | A set is 'dominated' by another if a one-to-one function maps the first set into a subset of the second [Enderton] |
9715 | An 'equivalence relation' is a reflexive, symmetric and transitive binary relation [Enderton] |
9716 | We 'partition' a set into distinct subsets, according to each relation on its objects [Enderton] |
9722 | Inference not from content, but from the fact that it was said, is 'conversational implicature' [Enderton] |
9718 | Validity is either semantic (what preserves truth), or proof-theoretic (following procedures) [Enderton] |
9721 | A logical truth or tautology is a logical consequence of the empty set [Enderton] |
9994 | A truth assignment to the components of a wff 'satisfy' it if the wff is then True [Enderton] |
9719 | A proof theory is 'sound' if its valid inferences entail semantic validity [Enderton] |
9720 | A proof theory is 'complete' if semantically valid inferences entail proof-theoretic validity [Enderton] |
9995 | Proof in finite subsets is sufficient for proof in an infinite set [Enderton] |
9996 | Expressions are 'decidable' if inclusion in them (or not) can be proved [Enderton] |
9997 | For a reasonable language, the set of valid wff's can always be enumerated [Enderton] |
23855 | Creation produced a network or web of determinations [Weil] |
9723 | Sentences with 'if' are only conditionals if they can read as A-implies-B [Enderton] |
3449 | If parallelism is true, how does the mind know about the body? [Crease] |
23848 | The aesthete's treatment of beauty as amusement is sacreligious; beauty should nourish [Weil] |
23854 | Beauty is the proof of what is good [Weil] |
23837 | Respect is our only obligation, which can only be expressed through deeds, not words [Weil] |
23844 | The most important human need is to have multiple roots [Weil] |
23838 | The need for order stands above all others, and is understood via the other needs [Weil] |
23836 | Obligations only bind individuals, not collectives [Weil] |
23840 | A citizen should be able to understand the whole of society [Weil] |
23843 | Even the poorest should feel collective ownership, and participation in grand display [Weil] |
23846 | Culture is an instrument for creating an ongoing succession of teachers [Weil] |
23839 | A lifelong head of society should only be a symbol, not a ruler [Weil] |
23842 | Party politics in a democracy can't avoid an anti-democratic party [Weil] |
23847 | Socialism tends to make a proletariat of the whole population [Weil] |
23845 | The capitalists neglect the people and the nation, and even their own interests [Weil] |
23841 | By making money the sole human measure, inequality has become universal [Weil] |
23835 | People have duties, and only have rights because of the obligations of others to them [Weil] |
23852 | To punish people we must ourselves be innocent - but that undermines the desire to punish [Weil] |
23850 | The soldier-civilian distinction should be abolished; every citizen is committed to a war [Weil] |
23851 | Education is essentially motivation [Weil] |
23849 | Religion should quietly suffuse all human life with its light [Weil] |