20 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] |
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] |
23304 | The ancient Memorists said virtually all types of thinking could be done simply by memory [Sorabji] |
23303 | Stoics say true memory needs reflection and assent, but animals only have perceptual recognition [Sorabji] |
5662 | Maybe induction could never prove the existence of something unobservable [Ayer] |
5664 | Consciousness must involve a subject, and only bodies identify subjects [Ayer] |
5668 | People own conscious states because they are causally related to the identifying body [Ayer] |
5661 | We identify experiences by their owners, so we can't define owners by their experiences [Ayer] |
5665 | Memory is the best proposal as what unites bundles of experiences [Ayer] |
5666 | Not all exerience can be remembered, as this would produce an infinite regress [Ayer] |
5669 | Personal identity can't just be relations of experiences, because the body is needed to identify them [Ayer] |