6 ideas
19404 | Necessities rest on contradiction, and contingencies on sufficient reason [Leibniz] |
6408 | Russell needed three extra axioms to reduce maths to logic: infinity, choice and reducibility [Grayling] |
6414 | Two propositions might seem self-evident, but contradict one another [Grayling] |
13304 | Learned men gain more in one day than others do in a lifetime [Posidonius] |
19403 | Each of the infinite possible worlds has its own laws, and the individuals contain those laws [Leibniz] |
20820 | Time is an interval of motion, or the measure of speed [Posidonius, by Stobaeus] |