Individual Utilities and Utilitarian Ethics

Abstract

The fundamental assumption of utilitarian theory is that we ought to choose our moral standards by rational criteria, more particularly, that we ought to choose the moral standards of the highest expected social utility.¹ Here “expected” stands for “the expected value of ”, while “social utility” refers to the arithmetic mean (or possibly the sum) of all individuals’ utility levels. (Except in discussing the problem of optimum population, we can regard the number of individuals in society as given so that maximizing the arithmetic mean and maximizing the sum of individual utilities will be mathematically equivalent.) Of course, either definition of social utility assumes that individual utilities are cardinal quantities measurable on an interval scale and are interpersonally comparable in a meaningful manner. For convenience, I will sometimes use the term “social-utility function” instead of “social utility”. Note that many economists would employ the term “social welfare function” to describe what I will call “social utility” or the “social-utility function”.