4 ideas
17743 | De Morgan introduced a 'universe of discourse', to replace Boole's universe of 'all things' [De Morgan, by Walicki] |
8249 | Class membership is not transitive, unlike being part of a part of the whole [Lesniewski, by George/Van Evra] |
10486 | If we are rebuilding our ship at sea, we should jettison some cargo [Boolos on Neurath] |
8485 | We must always rebuild our ship on the open sea; we can't reconstruct it properly in dry-dock [Neurath] |