The author of this paper explores a central strand in the complex relationship between Peirce and Kant. He argues, against Kant (especially as reconstructed by Christine Korsgaard), that the practical identity of the self-critical agent who undertakes a Critic of reason (as Peirce insisted upon translating this expression) needs to be conceived in substantive, not purely formal, terms. Thus, insofar as there is a reflexive turn in Peirce, it is quite far from the transcendental turn taken by Immanuel Kant. The identity of the being devoted to redefining the bounds of reason (for the drawing of such bounds is always a historically situated and motivated undertaking) is not that of a disembodied, rational will giving laws to itself. Nor is it that of a being whose passions and especially sentiments are heteronomous determinations of the deliberative agency in question. Rather the identity of this being is that of a somatic, social, and historical agent whose very autonomy not only traces its origin to heteronomy but also ineluctably involves an identification with what, time and again, emerges as other than this agent.
A strong claim is made regarding human identity being practical identity (practical identity being understood here as the singular shape acquired by a human being in the complex course of its practical involvements, its participation in the array of practices in and through which such a being carries out its life). An equally strong claim is made regarding the upshot of Peirce's decisive movement beyond Kant's transcendental project: this movement unquestionably drives toward a compelling account of human agency.