4 ideas
18465 | An 'equivalence' relation is one which is reflexive, symmetric and transitive [Kunen] |
20544 | Berlin distinguishes 'negative' and 'positive' liberty, and rejects the latter [Berlin, by Swift] |
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] |