Résumé en anglais

Utilitarianism represents a major reference to which Sen's writings refer back when it comes to the ethics of collective choices. Which utilitarianism is it; Sentham and Sidgwick's historical utilitarianism, the utilitarianism impregnated with marginal calculation a la Edgeworth, or the contemporary utilitarianism of Harsanyi and Hammond? This article's approach is, that what Sen calls "utilitarianism" is the result of a personal construction which serves various purposes. It gives him first of all a unified frame of reference which polarises all the criticisms which he formulates concerning the economic theory of rational individual and collective choices. However, it also suggests some technical possibilities for introducing the ethical dimension into economic analysis.