The Universalizability Dilemma

Abstract

According to the Universalizability Principle, similar objects exhibit similar moral characteristics. This claim may be thought to be either trivial or unclear, depending on whether we interpret similarity as indiscernibility (cf. Leibniz’s thesis about the identity of indiscernibles) or as identity in morally relevant respects (the notion of relevance seems to be essentially opaque). In Rabinowicz (1979), Part III, I have argued that there is a simple way out of this dilemma: we can construct a version of the Universalizability Principle which does not make any reference to the notion of relevance but which nevertheless avoids getting trivialized by Leibniz’s thesis. Here follows a short and, hopefully, somewhat improved formulation of the same argument. For some of the improvements I am indebted to Sten Lindström and Sten Kaijser.