18 ideas
15545 | Armstrong's analysis seeks truthmakers rather than definitions [Lewis] |
13838 | A decent modern definition should always imply a semantics [Hacking] |
15546 | Predications aren't true because of what exists, but of how it exists [Lewis] |
15548 | Say 'truth is supervenient on being', but construe 'being' broadly [Lewis] |
14399 | Presentism says only the present exists, so there is nothing for tensed truths to supervene on [Lewis] |
13833 | 'Thinning' ('dilution') is the key difference between deduction (which allows it) and induction [Hacking] |
13834 | Gentzen's Cut Rule (or transitivity of deduction) is 'If A |- B and B |- C, then A |- C' [Hacking] |
13835 | Only Cut reduces complexity, so logic is constructive without it, and it can be dispensed with [Hacking] |
13845 | The various logics are abstractions made from terms like 'if...then' in English [Hacking] |
13840 | First-order logic is the strongest complete compact theory with Löwenheim-Skolem [Hacking] |
13844 | A limitation of first-order logic is that it cannot handle branching quantifiers [Hacking] |
13842 | Second-order completeness seems to need intensional entities and possible worlds [Hacking] |
13837 | With a pure notion of truth and consequence, the meanings of connectives are fixed syntactically [Hacking] |
13839 | Perhaps variables could be dispensed with, by arrows joining places in the scope of quantifiers [Hacking] |
13843 | If it is a logic, the Löwenheim-Skolem theorem holds for it [Hacking] |
15543 | How do things combine to make states of affairs? Constituents can repeat, and fail to combine [Lewis] |
16635 | Incorporeal substances are powers or forces [Descartes, by Pasnau] |
16684 | Impenetrability only belongs to the essence of extension [Descartes] |