8 ideas
| 10882 | Predicative definitions only refer to entities outside the defined collection [Horsten] |
| 10884 | A theory is 'categorical' if it has just one model up to isomorphism [Horsten] |
| 10885 | Computer proofs don't provide explanations [Horsten] |
| 10881 | The concept of 'ordinal number' is set-theoretic, not arithmetical [Horsten] |
| 22725 | When players don't meet again, defection is the best strategy [Axelrod] |
| 22724 | Good strategies avoid conflict, respond to hostility, forgive, and are clear [Axelrod] |
| 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] |