Pierre Force studies the history of the concept of self-interest to understand its meaning by the time that Adam Smith used it as an axiom in The Wealth of Nations. He demonstrates that Smith, unlike many of his predecessors and contemporaries, never endorsed the idea that self-interest is the motivation behind all human action, although the "selfish hypothesis" did have a place in his doctrine. This book provides insight on classic puzzles of economic theory and is a major work from an outstanding scholar.