While pleasure mobilizes the world in endless ways, it is also one of the most controversial of the central elements of human life. It is so idiosyncratic, so private, that it is difficult to define, but at the same time this indeterminacy is part of what is so fascinating and engrossing about it. Lionel Tiger's lively prose identifies some major forms of pleasure, such as sex, food and drugs, and explores their variations now and in the past. Tiger's other books include "Men in Groups", "The Imperial Manual" and "The Manufacture of Evil".