100 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] |
9738 | Each line of a truth table is a model [Fitting/Mendelsohn] |
9727 | Modal logic adds □ (necessarily) and ◊ (possibly) to classical logic [Fitting/Mendelsohn] |
9726 | We let 'R' be the accessibility relation: xRy is read 'y is accessible from x' [Fitting/Mendelsohn] |
9737 | The symbol ||- is the 'forcing' relation; 'Γ ||- P' means that P is true in world Γ [Fitting/Mendelsohn] |
13136 | The prefix σ names a possible world, and σ.n names a world accessible from that one [Fitting/Mendelsohn] |
13727 | A 'constant' domain is the same for all worlds; 'varying' domains can be entirely separate [Fitting/Mendelsohn] |
9734 | Modern modal logic introduces 'accessibility', saying xRy means 'y is accessible from x' [Fitting/Mendelsohn] |
9736 | A 'model' is a frame plus specification of propositions true at worlds, written < G,R,||- > [Fitting/Mendelsohn] |
9735 | A 'frame' is a set G of possible worlds, with an accessibility relation R, written < G,R > [Fitting/Mendelsohn] |
9741 | Accessibility relations can be 'reflexive' (self-referring), 'transitive' (carries over), or 'symmetric' (mutual) [Fitting/Mendelsohn] |
13149 | S5: a) if n ◊X then kX b) if n ¬□X then k ¬X c) if n □X then k X d) if n ¬◊X then k ¬X [Fitting/Mendelsohn] |
13141 | Negation: if σ ¬¬X then σ X [Fitting/Mendelsohn] |
13138 | Disj: a) if σ ¬(X∨Y) then σ ¬X and σ ¬Y b) if σ X∨Y then σ X or σ Y [Fitting/Mendelsohn] |
13142 | Existential: a) if σ ◊X then σ.n X b) if σ ¬□X then σ.n ¬X [n is new] [Fitting/Mendelsohn] |
13144 | T reflexive: a) if σ □X then σ X b) if σ ¬◊X then σ ¬X [Fitting/Mendelsohn] |
13145 | D serial: a) if σ □X then σ ◊X b) if σ ¬◊X then σ ¬□X [Fitting/Mendelsohn] |
13146 | B symmetric: a) if σ.n □X then σ X b) if σ.n ¬◊X then σ ¬X [n occurs] [Fitting/Mendelsohn] |
13147 | 4 transitive: a) if σ □X then σ.n □X b) if σ ¬◊X then σ.n ¬◊X [n occurs] [Fitting/Mendelsohn] |
13148 | 4r rev-trans: a) if σ.n □X then σ □X b) if σ.n ¬◊X then σ ¬◊X [n occurs] [Fitting/Mendelsohn] |
9740 | If a proposition is possibly true in a world, it is true in some world accessible from that world [Fitting/Mendelsohn] |
9739 | If a proposition is necessarily true in a world, it is true in all worlds accessible from that world [Fitting/Mendelsohn] |
13137 | Conj: a) if σ X∧Y then σ X and σ Y b) if σ ¬(X∧Y) then σ ¬X or σ ¬Y [Fitting/Mendelsohn] |
13140 | Bicon: a)if σ(X↔Y) then σ(X→Y) and σ(Y→X) b) [not biconditional, one or other fails] [Fitting/Mendelsohn] |
13139 | Implic: a) if σ ¬(X→Y) then σ X and σ ¬Y b) if σ X→Y then σ ¬X or σ Y [Fitting/Mendelsohn] |
13143 | Universal: a) if σ ¬◊X then σ.m ¬X b) if σ □X then σ.m X [m exists] [Fitting/Mendelsohn] |
9742 | The system K has no accessibility conditions [Fitting/Mendelsohn] |
13114 | □P → P is not valid in D (Deontic Logic), since an obligatory action may be not performed [Fitting/Mendelsohn] |
9743 | The system D has the 'serial' conditon imposed on its accessibility relation [Fitting/Mendelsohn] |
9744 | The system T has the 'reflexive' conditon imposed on its accessibility relation [Fitting/Mendelsohn] |
9746 | The system K4 has the 'transitive' condition on its accessibility relation [Fitting/Mendelsohn] |
9745 | The system B has the 'reflexive' and 'symmetric' conditions on its accessibility relation [Fitting/Mendelsohn] |
9747 | The system S4 has the 'reflexive' and 'transitive' conditions on its accessibility relation [Fitting/Mendelsohn] |
9748 | System S5 has the 'reflexive', 'symmetric' and 'transitive' conditions on its accessibility relation [Fitting/Mendelsohn] |
9404 | Modality affects content, because P→◊P is valid, but ◊P→P isn't [Fitting/Mendelsohn] |
13112 | In epistemic logic knowers are logically omniscient, so they know that they know [Fitting/Mendelsohn] |
13111 | Read epistemic box as 'a knows/believes P' and diamond as 'for all a knows/believes, P' [Fitting/Mendelsohn] |
13113 | F: will sometime, P: was sometime, G: will always, H: was always [Fitting/Mendelsohn] |
13728 | The Barcan says nothing comes into existence; the Converse says nothing ceases; the pair imply stability [Fitting/Mendelsohn] |
13729 | The Barcan corresponds to anti-monotonicity, and the Converse to monotonicity [Fitting/Mendelsohn] |
14352 | '¬', '&', and 'v' are truth functions: the truth of the compound is fixed by the truth of the components [Jackson] |
9725 | 'Predicate abstraction' abstracts predicates from formulae, giving scope for constants and functions [Fitting/Mendelsohn] |
6984 | Smooth reductions preserve high-level laws in the lower level [Jackson] |
16062 | A necessary relation between fact-levels seems to be a further irreducible fact [Lynch/Glasgow] |
16061 | If some facts 'logically supervene' on some others, they just redescribe them, adding nothing [Lynch/Glasgow] |
16060 | Nonreductive materialism says upper 'levels' depend on lower, but don't 'reduce' [Lynch/Glasgow] |
16064 | The hallmark of physicalism is that each causal power has a base causal power under it [Lynch/Glasgow] |
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] |
13730 | The Indiscernibility of Identicals has been a big problem for modal logic [Fitting/Mendelsohn] |
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] |
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] |
13725 | □ must be sensitive as to whether it picks out an object by essential or by contingent properties [Fitting/Mendelsohn] |
13731 | Objects retain their possible properties across worlds, so a bundle theory of them seems best [Fitting/Mendelsohn] |
13726 | Counterpart relations are neither symmetric nor transitive, so there is no logic of equality for them [Fitting/Mendelsohn] |
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] |