If it were true that every innate predisposition of an organism were the result of some selectional pressure, then I would have to conclude that my dog has been selected for chasing tennis balls.
-- John Searle
Voted this up, but of course Searle's dog was selected for chasing things similar enough to tennis balls.
A monthly thread for posting any interesting rationality-related quotes you've seen recently on the Internet, or had stored in your quotesfile for ages.