“Everybody to count for one, nobody for more than one”

The paper explores the meaning of the principle of equal consideration of interests as expressed by the famous dictum that John Stuart Mill attributed to Jeremy Bentham: “everybody to count for one, nobody for more than one”. It examines the contributions of these two authors and the comments by Henry Sidgwick, Stanley W. Jevons, Francis Y. Edgeworth and Arthur C. Pigou. The hedonistic and cardinalistic assumptions that these authors shared made the question of how to weigh the happiness of different individuals crucial for the application of utilitarian ethics, since the distribution of happiness and the distribution of the means of happiness were strictly related in this perspective. In particular, the hedonistic approach suggested to Edgeworth a strong argument in favour of inequality, and a comparison of his conclusions with those of his predecessors – and with those of Pigou after him – is essential to understand the limits of the egalitarian implications of utilitarian ethics.