INTRODUCTION

In some of the most widely cited, and certainly the most criticized, passages from the Metaphysics of Morals, Kant infamously insists that we human beings have duties to all human beings: “a human being is under obligation to regard himself, as well as every other human being, as his end” (MS 6:410); but “a human being has duties only to human beings (himself and others)” (MS 6:442). While Kant recognizes many moral constraints upon our behavior toward non-human animals, he insists that these are only duties “with regard to these animals,” rather than duties “to those beings” (MS 6:442–43). “Every human being has a legitimate claim to respect from his fellow human beings and is in turn bound to respect every other”(MS 6:462), but animals are “things,” not persons, and “respect is always directed only to persons, never to things” (KpV 5:76). If anyone thinks otherwise, that is due to an “amphiboly in his concepts of reflection.” It seems as if Kant thinks an animal is no more worthy of our concern than is a turnspit on which we might choose to roast it.

This position on the nature and scope of fundamental “moral status” and its practical implications, both for the treatment of so-called “marginal cases” of seriously immature or radically disabled human beings and for the treatment of non-human animals, has been a source of much consternation.