Rationalization refers to the development of rationality and calculation, rather than morals or emotions, as the main motivating factors in a society. According to Weber, the development of modern capitalism and its ideal work ethic represented the rationalization of western society.
Weber's writings on the "spirit of capitalism" describe the relationship between the Protestant style of work ethic and the development of modern capitalism. According to Weber, features of modern capitalist ideology that originated in Protestantism are understanding the pursuit of profit as inherently virtuous, and viewing profit as an end in itself. Protestant ideology suggests that humans have "callings," which provides a spiritual element to worldly activities and emphasizes the moral significance of work. Additionally, the Calvinist belief in predestination suggested that worldly success must be a sign that one has been chosen to be 'saved" by God. While Weber does not suggest that all of capitalism was based on the Protestant work ethic, he does point to ideological similarities between the two to trace the development of contemporary capitalist ideology in the rationalization of western society.