19 ideas
| 14352 | '¬', '&', and 'v' are truth functions: the truth of the compound is fixed by the truth of the components [Jackson] |
| 18200 | Very large sets should be studied in an 'if-then' spirit [Putnam] |
| 18199 | Indispensability strongly supports predicative sets, and somewhat supports impredicative sets [Putnam] |
| 8857 | We must quantify over numbers for science; but that commits us to their existence [Putnam] |
| 14360 | Possible worlds for subjunctives (and dispositions), and no-truth for indicatives? [Jackson] |
| 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] |
| 9169 | A statement can be metaphysically necessary and epistemologically contingent [Putnam] |
| 5819 | Conceivability is no proof of possibility [Putnam] |
| 9168 | I can't distinguish elm trees, but I mean by 'elm' the same set of trees as everybody else [Putnam] |
| 5820 | 'Water' has an unnoticed indexical component, referring to stuff around here [Putnam] |
| 9170 | We need to recognise the contribution of society and of the world in determining reference [Putnam] |
| 5817 | Language is more like a cooperative steamship than an individual hammer [Putnam] |
| 5818 | If water is H2O in the actual world, there is no possible world where it isn't H2O [Putnam] |