91 ideas
6979 | Serious metaphysics cares about entailment between sentences [Jackson] |
6980 | Conceptual analysis studies whether one story is made true by another story [Jackson] |
6983 | Intuitions about possibilities are basic to conceptual analysis [Jackson] |
14707 | Conceptual analysis is needed to establish that metaphysical reductions respect original meanings [Jackson, by Schroeter] |
7005 | Something can only have a place in a preferred account of things if it is entailed by the account [Jackson] |
6994 | Truth supervenes on being [Jackson] |
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] |
13201 | ∈ says the whole set is in the other; ⊆ says the members of the subset are in the other [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] |
13204 | The 'ordered pair' <x,y> is defined to be {{x}, {x,y}} [Enderton] |
13206 | A 'linear or total ordering' must be transitive and satisfy trichotomy [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] |
13200 | Note that {Φ} =/= Φ, because Φ ∈ {Φ} but Φ ∉ Φ [Enderton] |
13199 | The empty set may look pointless, but many sets can be constructed from it [Enderton] |
13203 | The singleton is defined using the pairing axiom (as {x,x}) [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] |
13202 | Fraenkel added Replacement, to give a theory of ordinal numbers [Enderton] |
13205 | We can only define functions if Choice tells us which items are involved [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] |
14352 | '¬', '&', and 'v' are truth functions: the truth of the compound is fixed by the truth of the components [Jackson] |
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] |
13007 | Archimedes defined a straight line as the shortest distance between two points [Archimedes, by Leibniz] |
6984 | Smooth reductions preserve high-level laws in the lower level [Jackson] |
6978 | Baldness is just hair distribution, but the former is indeterminate, unlike the latter [Jackson] |
6993 | Redness is a property, but only as a presentation to normal humans [Jackson] |
8499 | Nominalists cannot translate 'red resembles pink more than blue' into particulars [Jackson] |
8500 | Colour resemblance isn't just resemblance between things; 'colour' must be mentioned [Jackson] |
14633 | How do we tell a table's being contingently plastic from its being essentially plastic? [Jackson] |
14635 | An x is essentially F if it is F in every possible world in which it appears [Jackson] |
14632 | Quine may have conflated de re and de dicto essentialism, but there is a real epistemological problem [Jackson] |
6987 | We should not multiply senses of necessity beyond necessity [Jackson] |
14360 | Possible worlds for subjunctives (and dispositions), and no-truth for indicatives? [Jackson] |
14288 | 'If A,B' affirms that A⊃B, and also that this wouldn't change if A were certain [Jackson, by Edgington] |
13769 | Conditionals are truth-functional, but should only be asserted when they are confident [Jackson, by Edgington] |
13858 | The truth-functional account of conditionals is right, if the antecedent is really acceptable [Jackson, by Edgington] |
14289 | There are some assertable conditionals one would reject if one learned the antecedent [Jackson, by Edgington] |
14353 | Modus ponens requires that A→B is F when A is T and B is F [Jackson] |
14354 | When A and B have the same truth value, A→B is true, because A→A is a logical truth [Jackson] |
14355 | (A&B)→A is a logical truth, even if antecedent false and consequent true, so it is T if A is F and B is T [Jackson] |
14358 | In the possible worlds account of conditionals, modus ponens and modus tollens are validated [Jackson] |
14359 | Only assertions have truth-values, and conditionals are not proper assertions [Jackson] |
14357 | Possible worlds account, unlike A⊃B, says nothing about when A is false [Jackson] |
14356 | We can't insist that A is relevant to B, as conditionals can express lack of relevance [Jackson] |
9723 | Sentences with 'if' are only conditionals if they can read as A-implies-B [Enderton] |
14631 | How can you show the necessity of an a posteriori necessity, if it might turn out to be false? [Jackson] |
6988 | Mathematical sentences are a problem in a possible-worlds framework [Jackson] |
6975 | Possible worlds could be concrete, abstract, universals, sentences, or properties [Jackson] |
6982 | Long arithmetic calculations show the a priori can be fallible [Jackson] |
6991 | We examine objects to determine colour; we do not introspect [Jackson] |
4894 | I say Mary does not have new knowledge, but knows an old fact in a new way [Perry on Jackson] |
4895 | Is it unfair that physicalist knowledge can be written down, but dualist knowledge can't be [Perry on Jackson] |
4886 | Mary knows all the physical facts of seeing red, but experiencing it is new knowledge [Jackson] |
6976 | In physicalism, the psychological depends on the physical, not the other way around [Jackson] |
6986 | Is the dependence of the psychological on the physical a priori or a posteriori? [Jackson] |
6992 | If different states can fulfil the same role, the converse must also be possible [Jackson] |
7880 | If a blind persons suddenly sees a kestrel, that doesn't make visual and theoretical kestrels different [Papineau on Jackson] |
7378 | No one bothers to imagine what it would really be like to have ALL the physical information [Dennett on Jackson] |
7377 | Mary learns when she sees colour, so her complete physical information had missed something [Jackson] |
6996 | Folk psychology covers input, internal role, and output [Jackson] |
6977 | Egocentric or de se content seems to be irreducibly so [Jackson] |
6990 | Keep distinct the essential properties of water, and application conditions for the word 'water' [Jackson] |
6985 | Analysis is finding necessary and sufficient conditions by studying possible cases [Jackson] |
6995 | Successful predication supervenes on nature [Jackson] |
6989 | I can understand "He has a beard", without identifying 'he', and hence the truth conditions [Jackson] |
6998 | Folk morality does not clearly distinguish between doing and allowing [Jackson] |
6997 | Moral functionalism says moral terms get their meaning from their role in folk morality [Jackson] |
7000 | Which are prior - thin concepts like right, good, ought; or thick concepts like kindness, equity etc.? [Jackson] |
6999 | It is hard to justify the huge difference in our judgements of abortion and infanticide [Jackson] |