25 ideas
13838 | A decent modern definition should always imply a semantics [Hacking] |
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] |
12766 | Logical space is abstracted from the actual world [Stalnaker] |
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] |
12764 | For the bare particular view, properties must be features, not just groups of objects [Stalnaker] |
12761 | An essential property is one had in all the possible worlds where a thing exists [Stalnaker] |
12763 | Necessarily self-identical, or being what it is, or its world-indexed properties, aren't essential [Stalnaker] |
12762 | Bare particular anti-essentialism makes no sense within modal logic semantics [Stalnaker] |
16422 | The necessity of a proposition concerns reality, not our words or concepts [Stalnaker] |
16423 | Conceptual possibilities are metaphysical possibilities we can conceive of [Stalnaker] |
16421 | Critics say there are just an a priori necessary part, and an a posteriori contingent part [Stalnaker] |
16429 | A 'centred' world is an ordered triple of world, individual and time [Stalnaker] |
12765 | Why imagine that Babe Ruth might be a billiard ball; nothing useful could be said about the ball [Stalnaker] |
16428 | Meanings aren't in the head, but that is because they are abstract [Stalnaker] |
16432 | One view says the causal story is built into the description that is the name's content [Stalnaker] |
16430 | Two-D says that a posteriori is primary and contingent, and the necessity is the secondary intension [Stalnaker] |
16431 | In one view, the secondary intension is metasemantic, about how the thinker relates to the content [Stalnaker] |