Philosophical Books Vol. 49 No. 2 April 2008 pp. 125 –137 AUTONOMY, TAKING ONE’S CHOICES TO BE GOOD, AND PRACTICAL LAW: REPLIES TO CRITICS andrews reath The University of California, Riverside I Several essays in my book try to understand what Kant means by autonomy and how that concept figures in his foundational project. Since political and juridical terminology runs through much of Kant’s moral theory, I suggest that he models autonomy on a notion of sovereignty. I interpret autonomy not as a motivational capacity, but as the sovereignty of the will over itself: the rational will is not bound to any outside authority and it has the capacity to give universal law. I shall begin with an overview of some of these themes. Since Samuel Kerstein asks whether I am interpreting or defending Kant, let me first say something about my approach. My guiding aim is to reconstruct the underlying ideas and arguments so as to make them philosophically success- ful, where ‘reconstruction’ permits pushing an idea farther in a certain direc- tion than Kant did. My approach is interpretive, since I accept the constraint that the ideas that I develop should have a firm basis in the texts and the underlying arguments. Without claiming that there is a uniquely right reading, I want to get at the deep structure of concepts and arguments that animate the movements of thought in Kant’s texts. But I am also engaged in defending Kant, in that I am trying, as far as I can, to make the arguments work out. Thus a second constraint is that the ideas and arguments attributed to Kant turn out to be philosophically successful. These two constraints are not always compatible, and that is one reason why Kant is hard work (and sometimes frustrating). II To provide background for my responses, I begin with some remarks about the role of autonomy in the overall trajectory of the Groundwork that may clarify the senses in which Kant thinks that moral requirements are laws that the will gives to itself. (Here I am more concerned to lay out an overall picture of what goes on in the Groundwork than to defend it.) Kant thinks that it is part of common moral thought that moral requirements apply with absolute necessity and that we take them to be categorical imperatives. Once this feature of common moral thought is brought to our attention, the question that sets the problematic of the Groundwork naturally arises: how could there be normative requirements with this kind of necessity? Groundwork III attempts to ground the authority of moral requirements in a dual necessity. Greatly simplified, it argues that the Categorical Imperative [CI] is the constitutive or internal principle of a necessary self-conception. First, the CI is the constitutive principle of free Philosophical 2008 The Books Author. Vol. Journal 49 No. 2 compilation © 2008 Blackwell Publishing Ltd. © 2008 The Author. Journal compilation © 2008 Blackwell Publishing Ltd., 9600 Garsington Road, Oxford, OX4 2DQ , UK and 350 Main Street, Malden, MA 02148, USA