Stephen Engstrom provides a highly original interpretation of the categorical imperative as the criterion of rational knowledge and action. In focusing on the general formula and the law-of-nature variant, and trying to make them work, the book presents a welcome counterweight to currently fashionable interpretations that dismiss these formulations in favour of the second variation, commonly called the "formula of humanity."
   --Jens Timmermann, University of St Andrews

Stephen Engstrom is Professor of Philosophy at the University of Pittsburgh.