47 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] |
| 13520 | A 'tautology' must include connectives [Wolf,RS] |
| 13524 | Deduction Theorem: T∪{P}|-Q, then T|-(P→Q), which justifies Conditional Proof [Wolf,RS] |
| 13522 | Universal Generalization: If we prove P(x) with no special assumptions, we can conclude ∀xP(x) [Wolf,RS] |
| 13521 | Universal Specification: ∀xP(x) implies P(t). True for all? Then true for an instance [Wolf,RS] |
| 13523 | Existential Generalization (or 'proof by example'): if we can say P(t), then we can say something is P [Wolf,RS] |
| 13529 | Empty Set: ∃x∀y ¬(y∈x). The unique empty set exists [Wolf,RS] |
| 13526 | Comprehension Axiom: if a collection is clearly specified, it is a set [Wolf,RS] |
| 13534 | In first-order logic syntactic and semantic consequence (|- and |=) nicely coincide [Wolf,RS] |
| 13535 | First-order logic is weakly complete (valid sentences are provable); we can't prove every sentence or its negation [Wolf,RS] |
| 13531 | Model theory reveals the structures of mathematics [Wolf,RS] |
| 13532 | Model theory 'structures' have a 'universe', some 'relations', some 'functions', and some 'constants' [Wolf,RS] |
| 13519 | Model theory uses sets to show that mathematical deduction fits mathematical truth [Wolf,RS] |
| 13533 | First-order model theory rests on completeness, compactness, and the Löwenheim-Skolem-Tarski theorem [Wolf,RS] |
| 13537 | An 'isomorphism' is a bijection that preserves all structural components [Wolf,RS] |
| 13539 | The LST Theorem is a serious limitation of first-order logic [Wolf,RS] |
| 13538 | If a theory is complete, only a more powerful language can strengthen it [Wolf,RS] |
| 13525 | Most deductive logic (unlike ordinary reasoning) is 'monotonic' - we don't retract after new givens [Wolf,RS] |
| 13530 | An ordinal is an equivalence class of well-orderings, or a transitive set whose members are transitive [Wolf,RS] |
| 13518 | Modern mathematics has unified all of its objects within set theory [Wolf,RS] |
| 6984 | Smooth reductions preserve high-level laws in the lower level [Jackson] |
| 16771 | A composite is a true unity if all of its parts fall under one essence [Scheibler] |
| 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] |
| 6987 | We should not multiply senses of necessity beyond necessity [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] |
| 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] |
| 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] |