What makes the book so compelling is the fluid combination of erudition and entertainment, and the author's obvious pleasure in challenging conventional wisdom. One minute he draws on psychological experiments to defend Glaucon, the cynic in Plato's Republic who argued that people behaved well only because they were scared of being caught. (Here Haidt gives dishonourable mention to Britain's MPs, so happy to abuse expenses when they thought no one was looking at their moats and duck ponds.) The next he is enlisting the Scottish philosopher David Hume to challenge our "rationalist delusion". He asks a series of strange questions – is it wrong to eat your dog if you run it over by accident, or to perform sexual intercourse on a dead chicken? – to prove how people rely on intuition to find answers, then produce reasons to justify them. Transcripts show how people tie themselves in knots arguing against incest, however much their arguments are torn apart. Reason, he concludes, is like a government press secretary, there to defend your decisions to others. "Anyone who values truth should stop worshipping reason."
While our ASET book club will focus on part 1 of Haidt's book, the entire text is well worth a read.