52 ideas
| 23728 | Analysis aims to express the full set of platitudes surrounding a given concept [Smith,M] |
| 23744 | Defining a set of things by paradigms doesn't pin them down enough [Smith,M] |
| 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] |
| 9723 | Sentences with 'if' are only conditionals if they can read as A-implies-B [Enderton] |
| 23743 | Capturing all the common sense facts about rationality is almost impossible [Smith,M] |
| 23739 | Goals need desires, and so only desires can motivate us [Smith,M] |
| 23724 | A pure desire could be criticised if it were based on a false belief [Smith,M] |
| 23736 | A person can have a desire without feeling it [Smith,M] |
| 23723 | In the Humean account, desires are not true/false, or subject to any rational criticism [Smith,M] |
| 23735 | Subjects may be fallible about the desires which explain their actions [Smith,M] |
| 23738 | Humeans (unlike their opponents) say that desires and judgements can separate [Smith,M] |
| 23742 | If first- and second-order desires conflict, harmony does not require the second-order to win [Smith,M] |
| 23746 | Objective reasons to act might be the systematic desires of a fully rational person [Smith,M] |
| 23733 | Motivating reasons are psychological, while normative reasons are external [Smith,M] |
| 23740 | Humeans take maximising desire satisfaction as the normative reasons for actions [Smith,M] |
| 23745 | We cannot expect even fully rational people to converge on having the same desires for action [Smith,M] |
| 23731 | 'Externalists' say moral judgements are not reasons, and maybe not even motives [Smith,M] |
| 23732 | A person could make a moral judgement without being in any way motivated by it [Smith,M] |
| 23729 | Moral internalism says a judgement of rightness is thereby motivating [Smith,M] |
| 23730 | 'Rationalism' says the rightness of an action is a reason to perform it [Smith,M] |
| 23727 | Expressivists count attitudes as 'moral' if they concern features of things, rather than their mere existence [Smith,M] |
| 23741 | Is valuing something a matter of believing or a matter of desiring? [Smith,M] |
| 16713 | Philosophers are the forefathers of heretics [Tertullian] |
| 6610 | I believe because it is absurd [Tertullian] |