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] |
468 | Musical performance can reveal a range of virtues [Damon of Ath.] |
23896 | We see our character as a restricting limit, but also as an unshakable support [Weil] |
23894 | The concept of character is at the centre of morality [Weil] |
23893 | We don't see character in a single moment, but only over a period of time [Weil] |
23895 | We modify our character by placing ourselves in situations, or by attending to what seems trivial [Weil] |