Max Weber was fascinated by the differing historical paths traced by Western civilizaiton and the civilizations of the East. His essay, "The Protestant Ethic and the Spirit of Capitalism" addresses the forces behind the social transformations of the industrial revolution. Weber's thesis proposes a causal link between the forces of the "Protestant ethic" and the "spirit of capitalism". This analysis of Weber's key concepts provides an in-depth study of the evidence of their early formulation. It proposes an original distinction between the Protestant "work" and "profit" ethic and examines the relationship between them. The study compares Adam Smith's "spirit of capitalism" to Weber's, and considers the Protestant ethic in the modern world.