3 ideas
17743 | De Morgan introduced a 'universe of discourse', to replace Boole's universe of 'all things' [De Morgan, by Walicki] |
5880 | Xenocrates held that the soul had no form or substance, but was number [Xenocrates, by Cicero] |
11968 | The intension of a sentence is the set of all possible worlds in which it is true [Carnap, by Kaplan] |