21 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] |
5060 | All substances analyse down to simple substances, which are souls, or 'monads' [Leibniz] |
3546 | 'Phronesis' should translate as 'practical intelligence', not as prudence [Annas] |
3547 | Epicureans achieve pleasure through character development [Annas] |
3543 | Cyrenaics pursue pleasure, but don't equate it with happiness [Annas] |
3541 | Ancient ethics uses attractive notions, not imperatives [Annas] |
3550 | Principles cover life as a whole, where rules just cover actions [Annas] |
3551 | Virtue theory tries to explain our duties in terms of our character [Annas] |
3552 | If excessively good actions are admirable but not required, then duty isn't basic [Annas] |
3542 | We should do good when necessary, not maximise it [Annas] |
5059 | Power rules in efficient causes, but wisdom rules in connecting them to final causes [Leibniz] |