Kant tells us in the Groundwork of the Metaphysics of Morals that rational nature is an end in itself; that it is the only thing which is unconditionally valuable; and that it is the ultimate condition of all value.1 A striking trend in recent Kant scholarship is to regard these value claims, rather than the formalism of universalizability, as the ultimate foundation of Kant’s theory.2 But does rational nature as Kant conceives it deserve such veneration? Can it really carry the world of value on its shoulders? I think not. As will become clear, I do not doubt the value of rational nature. My claim is rather that we cannot account for the value of rational nature if we conceive it as Kant does. Rational nature cannot be valuable in a Kantian world, where there are no self-subsistent principles about what are good states of affairs, or activities, or whatever, of the sort that a Moorean or a Platonist or a perfectionist believes in. My own views are generally Moorean, and I shall occasionally offer a Moorean perspective on the value of rational nature for comparative purposes, but my criticisms of the Kantian view could be made from an Aristotelian perspective as well, in which the agent pursues not the Good, but a good human life. My main object is not to develop any particular alternative to the Kantian view, but merely to show how unsatisfactory the Kantian view is when we look at it closely. Some readers may think I do not give Kant a fair shake, because I pay almost no attention to any ethical writings except the Groundwork. I shall explain at a few points why I think some particular claim or argument from another work is unhelpful, but it is important to remember the nature of my project. I am interested in whether Kantian rational nature is valuable. I do not dispute here any of Kant’s claims about what would follow if it were once established that rational nature, as Kant conceives it, is valuable in the way he says. So far as I can see, the parts of the Metaphysics of Morals that discuss the value of rational nature are about what would follow.3 The Critique of Practical Reason contains some arguments for the value of rational nature, but none that are not already present in the Groundwork and discussed in Section I or Section IV below. In any event, the reader who thinks I am unfair to Kant can read this article as a critique, not of Kant himself, but of a prominent development in contemporary Kantianism. Perhaps I should also say something about what I mean by “value.” Arguably Kantians, Mooreans, and Aristotelians all have different ideas of the nature of value. But I shall proceed without much attention to any differences. I take it that on any understanding of “value,” to say something is valuable is (normally) to express some sort of pro-attitude toward it and (invariably) to assert that there is some aspect of it that makes such a pro-attitude appropriate. My claim is that if we look closely at rational nature as Kant, or some Kantians, conceive it, we will find nothing to justify a pro-attitude of any sort.
Regan, Donald H. "The Value of Rational Nature." Ethics 112, no. 2 (2002): 267-91.