General and Personal Good: Harsanyi's Contribution to the Theory of Value

Abstract

In 1955, John Harsanyi published a singular contribution to the theory of value (Harsanyi 1955). He proved a theorem that links together the valuation of uncertain prospects for a single person and the valuation of distributions of good across people. The theorem’s conclusion is important and remarkable; it is by no means obvious, and it requires some mathematics to uncover it. Perhaps as a consequence, philosophers of value have not always given this theorem the attention it deserves. This chapter describes and interprets the theorem, and explains its importance. Harsanyi uses the language of economics, and he sets his argument in a framework that is generally taken for granted by economists but not widely accepted in philosophy. He assumes that each person’s good consists in the satisfaction of her preferences. But his conclusion is about the relation between general good and the good of individual people. It is independent of particular assumptions about the nature of a person’s good, and I shall present it in a way that does not depend on any such assumptions.