Journal of the History of Philosophy

As is well known, Kant presents several versions of the Categorical Imperative in the Groundwork for the Metaphysics of Morals. Traditionally readers have focused on the “universal law” formulation (FUL) of his famous moral principle. Friends of Kant have found in the FUL an appealingly formal and seemingly rigorous criterion for right action, while foes have found in it a convenient whipping boy. Recently, however, much attention has shifted to the “humanity” formulation (FH) of the Categorical Imperative. The shift is motivated partly by a general exhaustion with the FUL and the problems it generates—for example, the emptiness charge, as well as the problem of false positives and false negatives—as well as by a widely accepted commitment to the general idea that every human being is worthy of respect. Scholars such as Thomas E. Hill, Jr., Christine Korsgaard, and Allen Wood have greatly enriched our understanding of Kant’s work by emphasizing the role of the FH in his moral theory. [End Page 327]

With his welcome new book, The Value of Humanity in Kant’s Moral Theory, Richard Dean joins the discussion. Dean’s main objective is to explain what Kant means by ‘humanity’ when he enjoins us to treat humanity as an end rather than a mere means. According to the dominant reading, Kant identifies humanity with the capacity to set ends and reason practically about how to achieve those ends. Some scholars add to this the capacity to respond appropriately to moral principles. Dean calls this the “minimal” reading. Against this interpretation, he argues that ‘humanity’ is “Kant’s name for the more fully rational nature that is only possessed by a being who actually accepts moral principles as providing sufficient reason for action” (6). He calls his position the “good will reading,” since it identifies the possession of humanity with the possession of a good will. On this reading, the FH commands us to treat only those with good wills as ends in themselves. This will sound excessively moralistic to Kant’s defenders. In response to this concern, Dean urges that (a) good wills are not rare, and (b) “there are sound Kantian reasons to treat every minimally rational human with respect and benevolence even if some of them lack good wills” (105). Demonstrating an impressive grasp of both the relevant texts and current scholarship, he argues that the good will reading has many advantages over the minimal reading. It renders more consistent Kant’s claims about value and dignity; it establishes tight connections among the various versions of the Categorical Imperative—especially between the FH and the “kingdom of ends” formulation; and it makes good sense of the idea that humanity is a moral ideal for Kant. Dean also offers a detailed defense his construal of the FH as a sound moral principle, showing how it can be used to address a host of concerns central to both normative and applied ethics.

Yet Dean’s view has its difficulties. Even if the good will reading is not overly moralistic, it renders the FH mute with respect to our treatment of strangers, for instance. On the good will reading, application of the FH requires judgments of character. But we are plainly not in the position to judge the character of strangers, since we have no acquaintance with their long-term volitional patterns. It follows that the FH would provide no reason to treat strangers as ends in themselves. One also wonders whether it could guide our treatment of the “humanity in our own person.” On the one hand, if I lack a good will, then the FH gives me no reason to regard my own will as an end in itself. Strictly speaking, there is no humanity in my person. On the other hand, if I already have a good will, then what would be the purpose of the FH? Apparently I already tend to treat the moral law as a sufficient basis for action. This places severe limits...