Abstract
James S. Coleman was the major proponent of rational choice theory. This article challenges the traditional reading of his work by showing that under the explicit theory of rational choice lay a latent non-rational theory of action. The article shows that instead of rationality, Coleman's psychological starting point was existential insecurity; that instead of the alleged mechanism of the maximization of utility, actors choose to conform to peer values and norms in order to alleviate insecurity; and that the optimal setting for action is provided by intimate and dense communities, rather than unregulated free markets. These three non-rational presuppositions are analyzed and it is suggested that they are crucial for understanding Coleman's assessment of modernity, social change and his call for the rational reconstruction of society.