I especially liked the discussion about what counts as "intelligent". If we "know" that each particle follow simple rules, and that the interaction of these rules only "looks" intelligent ... how is this different from the human body? Each cell follows simple rules, but put enough of the right kind of cells together and it suddenly seems intelligent.

So is a termite colony intelligent? Is it reasonable to discuss the intelligence of a swarm? Is there a meaningful difference between "intent" and "accident"? Good stuff.