Abstract
On a general level, this paper proposes a critical analysis of one of the attempts to make bridges between economics and moral and political philosophy. A priori, we may expect that formal methods may lead to clearer and more rigorous arguments, and may facilitate practical applications. However, this paper illustrates how precision is bought at the price of becoming tautological. Therefore, the statement that "it is already widely recognized that formal methods derived from economics can contribute to ethics" seems hasty. The paper is organized as follows: Section 2 discusses some philosophical background assumptions which underlie a decision theoretic argument in favour of utilitarianism. Section 3 recalls briefly John Harsanyi's decision theoretic arguments in favour of utilitarianism. It then focuses on the crucial assumption of separability in order to show that separability can always be saved as an assumption if one applies the strategy of dispersion. Section 4, finally, shows how the theorem may indeed reconcile the concern for equality and utilitarianism, at the price of becoming futile.