Haidt draws upon the analogy used in the ancient traditions of the East, which see reason as the rider on the back of a huge elephant consisting of all the other forces inside us:
. . . the rider is an advisor or servant: not king, president or charioteer with a firm grip on the reins. . . . The elephant, in contrast, is everything else. The elephant includes the gut feelings, the visceral reactions, emotions and intuitions that comprise much of the automatic system. The elephant and the rider each have their own intelligence, and when they work together well they enable the unique brilliance of human beings. But they don’t always work together well.
(From Jonathan Haidt’s book The Happiness Hypothesis – page 17)
(See ‘Limits of Reason‘ for more on this theme.)