display all the ideas for this combination of texts
4 ideas
8078 | Modus ponens is one of five inference rules identified by the Stoics [Chrysippus, by Devlin] |
1312 | If everything is and isn't then everything is true, and a midway between true and false makes everything false [Aristotle on Heraclitus] |
6023 | Every proposition is either true or false [Chrysippus, by Cicero] |
7332 | There is a huge range of sentences of which we do not know the logical form [Davidson] |