Abstract

This study provides a formal framework for considering the so-called "Universalizability Principle" in morality and its relation to such metaphysical theses as "Leibnizianism". That these claims are thought to be ethical and metaphysical in import provides the point of the subtitle. In spite of this, however, Rabinowicz's study is less an examination of the arguments which may be given for or against these claims or the uses which may be made of them in morals or metaphysics, than an attempt on a possible worlds model to frame them clearly and to explore their logical mesh. In the introductory chapter Rabinowicz is concerned first to make clear to us what principle it is which he wishes to designate as the Universalizability Principle and to distinguish it from certain others, e.g., the Golden Rule, Kant's Categorical Imperative, Singer's Generalization Principle, Hare's "thesis of universalizability," and principles of impartiality and fairness, with which it may be confused. Specifically, UP represents a claim that the moral properties of things are essentially independent of what might be called their "individual aspects." In terms of his framework, where w, v, u, and z are possible worlds, E represents an equivalence relation of some unspecified manner of sufficient similarity in non-individual aspects, and D is read as "is a deontic alternative to," UP has the following form: if wEv and wDu, then there is a z such that vDz and uEz. On this formulation we are enabled to see where the main problem with UP lies: E must be specified in such a way as to provide significance for UP, i.e., so as to provide us with a clear, non-trivial, non-vacuous formulation of UP which yet conforms to the intuitions of those ethicists who are "universalists." It is this problem and its proposed solution which constitutes the real theme of this book. For suppose that E is specified in terms of either of the two most intuitively obvious and appealing candidates, namely, "exact similarity" and "morally relevant similarity." Then, on Leibnizianism, the exact-similarity variant becomes trivial, whereas the relevant-similarity variant is, by virtue of the systematic unclarity of the notion of "relevance," confusing and useless. Because he accepts the possibility that Leibnizianism may be true, Rabinowicz conceives of his task as one of inquiring whether some third variant of UP can be framed which slips between the horns of this dilemma.