21 ideas
7823 | Lucretius was rediscovered in 1417 [Grayling] |
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] |
15645 | Nominal essence are the observable properties of things [Eagle] |
15642 | If kinds depend only on what can be observed, many underlying essences might produce the same kind [Eagle] |
15643 | Nominal essence mistakenly gives equal weight to all underlying properties that produce appearances [Eagle] |
7809 | In an honour code shame is the supreme punishment, and revenge is a duty [Grayling] |
7824 | If suicide is lawful, but assisting suicide is unlawful, powerless people are denied their rights [Grayling] |
15641 | Kinds are fixed by the essential properties of things - the properties that make it that kind of thing [Eagle] |
7819 | Religion gives answers, comforts, creates social order, and panders to superstition [Grayling] |
7817 | To make an afterlife appealing, this life has to be denigrated [Grayling] |
7818 | In Greek mythology only heroes can go to heaven [Grayling] |