12 ideas
14249 | Boolos reinterprets second-order logic as plural logic [Boolos, by Oliver/Smiley] |
10830 | Second-order logic metatheory is set-theoretic, and second-order validity has set-theoretic problems [Boolos] |
10829 | A sentence can't be a truth of logic if it asserts the existence of certain sets [Boolos] |
10832 | '∀x x=x' only means 'everything is identical to itself' if the range of 'everything' is fixed [Boolos] |
10834 | Weak completeness: if it is valid, it is provable. Strong: it is provable from a set of sentences [Boolos] |
13841 | Why should compactness be definitive of logic? [Boolos, by Hacking] |
10833 | Many concepts can only be expressed by second-order logic [Boolos] |
490 | Everything happens by reason and necessity [Leucippus] |
536 | We should follow the law in public, and nature in private [Antiphon] |
1557 | To gain the greatest advantage only treat law as important when other people are present [Antiphon] |
540 | The way you spend your time will form your character [Antiphon] |
539 | Nothing is worse for mankind than anarchy [Antiphon] |