Immanuel Kant: Kritik der praktischen Vernunft

"Pure Reason of Itself Alone Suffices to Determine the Will" (42–57) (S. 99-100)

6.1 Context and Structure of the Text

The main problem of KpV is to determine whether "pure reason is really practical" (3), that is, "whether pure reason of itself alone suffices to determine the will" (16). This problem receives its best known treatment in an appeal to what Kant calls the "fact of reason", das Faktum der Vernunft (6, 31, 42, 43, 47, 55, 91, 104). I will refer to the discussion of this issue in Sections I (42–50) and II (50–57) of KpV as the "Faktum Text".

Whereas Section I focuses on the fundamental claim that pure reason really is practical, Section II plays the secondary but essential role of responding to the objection that such an assertion can appear to transcend the bounds of what is permissible to say within the Critical philosophy itself. More specifically, it is clear that for Kant the key problem for the very possibility of morality is the special kind of absolute or "transcendental freedom" (3, 99) that he believes is obviously required if the authority of pure practical reason is not to be challenged as a mere "chimera". In providing, with the "fact of reason", a way of "showing" that pure practical reason in fact, or in deed (in der Tat, 42, this "proto-Fichtean" expression is stressed in Schwemmer 1986 and Willaschek 1992), is real, and therefore possible, Kant takes himself to have "deduced" the actuality of absolute freedom, and this claim raises the problem of whether an improper "extension" has been made in our use of reason.

Since Kant characterizes the concept of freedom as the "keystone" (5) of the "whole structure" of reason, it is only fitting that the Faktum Text’s discussion of the possibility of freedom and morality has a central position in the main part of KpV, right before Ch. II of the Analytic. Whereas the Karl Ameriks earlier part of Chapter I fills out the "principles" of morality, and thus gives its content an initial specification by arguing for various analytic relations between basic concepts of morality and freedom, Ch. II elaborates the "concept" of the "object" of freedom, namely good and evil, and Ch. III addresses the motivational issue of the "incentives" of pure practical reason. Kant’s ordering of these issues only a few years earlier in GMS (1785) is different. Section I begins with questions about the proper motive of moral action (acting "from" duty), Section II offers a formulation of morality’s pure "principle", and then Section III concludes the book with an account of morality’s key "concept", freedom (which is invoked to fill out a more detailed account of moral incentives). The argument of GMS thus goes in a direction that is precisely the reverse of the sequence of terms in its title – from "morals" to "metaphysics" and then to a "groundwork". The end of GMS provides the foundation for morality by presenting an argument for our freedom and autonomy from the mere notion of our having an "intelligible" will, and by grounding this "possibility" (IV 453) ultimately in the Critical doctrine of transcendental idealism.