19 ideas
13838 | A decent modern definition should always imply a semantics [Hacking] |
9355 | One sort of circularity presupposes a premise, the other presupposes a rule being used [Braithwaite, by Devitt] |
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] |
19718 | Indefeasibility does not imply infallibility [Grundmann] |
19717 | Can a defeater itself be defeated? [Grundmann] |
19716 | Simple reliabilism can't cope with defeaters of reliably produced beliefs [Grundmann] |
19715 | You can 'rebut' previous beliefs, 'undercut' the power of evidence, or 'reason-defeat' the truth [Grundmann] |
19713 | Defeasibility theory needs to exclude defeaters which are true but misleading [Grundmann] |
19714 | Knowledge requires that there are no facts which would defeat its justification [Grundmann] |
19719 | 'Moderate' foundationalism has basic justification which is defeasible [Grundmann] |