11 ideas
22752 | Reasoning is impossible without a preconception [Sext.Empiricus] |
13831 | Logic is based on transitions between sentences [Prawitz] |
13825 | Natural deduction introduction rules may represent 'definitions' of logical connectives [Prawitz] |
13823 | In natural deduction, inferences are atomic steps involving just one logical constant [Prawitz] |
1554 | Contradiction is impossible, since only one side of the argument refers to the true facts [Prodicus, by Didymus the Blind] |
22754 | Saying the good is useful or choiceworth or happiness-creating is not the good, but a feature of it [Sext.Empiricus] |
22755 | Like a warming fire, what is good by nature should be good for everyone [Sext.Empiricus] |
22756 | If a desire is itself desirable, then we shouldn't desire it, as achieving it destroys it [Sext.Empiricus] |
1555 | People used to think anything helpful to life was a god, as the Egyptians think the Nile a god [Prodicus] |
535 | The gods are just personified human benefits [Prodicus] |
1543 | He denied the existence of the gods, saying they are just exaltations of things useful for life [Prodicus] |