17 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] |
12708 | The soul is not a substance but a substantial form, the first active faculty [Leibniz] |
22971 | In moving from capitalism to communism a revolutionary dictatorship of the proletariat is needed [Marx] |
22000 | From each according to his ability, to each according to his need [Marx] |
22969 | People who only have their labour power are the slaves of those permitting them to work [Marx] |
22970 | Freedom is making the state subordinate to its society [Marx] |
22972 | Bourgeois 'freedom of conscience' just tolerates all sorts of religious intolerance [Marx] |