Rational choice theory has become very fashionable in all social sciences, from anthropology to history. Actually it is not a theory but a family of models that share two simple and attractive ideas. One of them is the version of the Rationality Postulate according to which people know what is best for them, and act accordingly. The other basic idea is that this feature of human cognition, valuation, choice, volition and action is all we need to know in order to account for social life anywhere and at any time. This is of course the Methodological Individualism Postulate. These two ideas, if true, would be extraordinarily powerful. Indeed, they would allow us to explain, predict and plan all human actions in any society. Furthermore, they would unify all of the social sciences and sociotechnologies. No wonder then that rational choice models have been mushrooming over the past half century in all of the so-called human sciences.