Cognitive scientist and philosopher Daniel Dennett is one of America's foremost thinkers. In this extract from his new book, he reveals some of the lessons life has taught him1 USE YOUR MISTAKESWe have all heard the forlorn refrain: "Well, it seemed like a good idea at the time!" This phrase has come to stand for the rueful reflection of an idiot, a sign of stupidity, but in fact we should appreci