4 ideas
13342 | Carnap defined consequence by contradiction, but this is unintuitive and changes with substitution [Tarski on Carnap] |
13251 | Each person is free to build their own logic, just by specifying a syntax [Carnap] |
5880 | Xenocrates held that the soul had no form or substance, but was number [Xenocrates, by Cicero] |
22489 | 'Good' is an attributive adjective like 'large', not predicative like 'red' [Geach, by Foot] |