The moral philosophy of the first half of the twentieth century, at least in the English-speaking part of the world, has been largely devoted to problems of an ontological or epistemological nature. This concentration of effort by many acute analytical minds has not produced any general agreement with respect to the solution of these problems; it seems likely, on the contrary, that the wealth of proposed solutions, each making some claim to plausibility, has resulted in greater disagreement than ever before, (...) and in some cases disagreement about issues so fundamental that certain schools of thought now find it unrewarding, if not impossible, to communicate with one another. Moral philosophers of almost all schools seem to agree, however, that no major possibility has been neglected during this period, and that every proposed solution which can be adjudged at all plausible has been examined with considerable thoroughness. It is now common practice, for example, for the authors of books on moral philosophy to introduce their own theories by what purports to be a classification and review of all \emph{possible} solutions to the basic problems of analysis; and in many cases, indeed, the primary defense of the author's own position seems to consist in the negative argument that his own position cannot fail to be correct because none of the others which he has mentioned is satisfactory. (shrink)