4 ideas
9548 | A mathematical object exists if there is no contradiction in its definition [Waterfield] |
7783 | Bodies, properties, relations, events, numbers, sets and propositions are 'things' if they exist [Lowe] |
13304 | Learned men gain more in one day than others do in a lifetime [Posidonius] |
20820 | Time is an interval of motion, or the measure of speed [Posidonius, by Stobaeus] |