Abstract

This paper tries to penetrate Jon Elster’s contribution to ratioanlity in the frame of the problem ofmeans and ends rationality. To treat rationality in Elster, we will study the imperfect rationality and its relation to weakness of will,and the development of precommitment strategies. We will also point out the role of Emotions, false beliefs and cognitive fallacies in the consideration of rationality. We Will show the difference that the author makes between the thin theory and the broad theory of rationality. Taking into account Hamlin’s distinction between means, beliefs, ends and extended rationality, we will explain the relation between his belief rationality and Elster’s broad theory.