5 ideas
| 21554 | Sets always exceed terms, so all the sets must exceed all the sets [Lackey] |
| 21553 | It seems that the ordinal number of all the ordinals must be bigger than itself [Lackey] |
| 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] |
| 5467 | Euler said nature is instrinsically passive, and minds cause change [Euler, by Ellis] |