11 ideas
| 12036 | Xenophanes began the concern with knowledge [Annas] |
| 12046 | Plato was the first philosopher who was concerned to systematize his ideas [Annas] |
| 23026 | We know mathematical axioms, such as subtracting equals from equals leaves equals, by a natural light [Leibniz] |
| 13189 | A necessary feature (such as air for humans) is not therefore part of the essence [Leibniz] |
| 19432 | Intelligible truth is independent of any external things or experiences [Leibniz] |
| 19430 | We know objects by perceptions, but their qualities don't reveal what it is we are perceiving [Leibniz] |
| 19431 | There is nothing in the understanding but experiences, plus the understanding itself, and the understander [Leibniz] |
| 12037 | Euripides's Medea is a key case of reason versus the passions [Annas] |
| 12040 | Virtue is a kind of understanding of moral value [Annas] |
| 1748 | Archelaus was the first person to say that the universe is boundless [Archelaus, by Diog. Laertius] |
| 5989 | Archelaus said life began in a primeval slime [Archelaus, by Schofield] |