3 ideas
17743 | De Morgan introduced a 'universe of discourse', to replace Boole's universe of 'all things' [De Morgan, by Walicki] |
7006 | Observing irrelevant items supports both 'all x are y' and 'all x are non-y', revealing its absurdity [Schofield,J] |
468 | Musical performance can reveal a range of virtues [Damon of Ath.] |