This chapter looks at Kant’s understanding of the relationship between laws of nature and those of freedom in order to further explain Kant’s grounding argument at 4:453. The two sets of laws constitute two systems, the first governing phenomenal nature and the second the intelligible world, that is, the systematic interrelation of rational wills. How the two sets of laws relate reveal one fundamental philosophical system that can be grasped correctly only from the standpoint of practical reason, namely, that of the agent making use of its intelligence in its practical activity. It is the same understanding and the very same transcendental subject who gives the law to nature, who also gives the law to itself, using the same set of concepts, only differently applied. Our law-giving function in both worlds grounds the primacy of our membership in the intelligible world. Different criteria of application of these concepts to noumenal and phenomenal worlds are discussed, and I show how Kant avoids objections to the idea of timeless agency. Kant espouses a modified Leibizianism through which the intelligible and sensible worlds are harmonized indirectly by the author of nature, who harmonizes the functions in us through which the two are constituted.

This chapter demonstrates that a correct understanding of Kant’s argument for the bindingness of the moral law in Groundwork III succeeds. Through his critique of the conditions of the possibility of the act of willing, Kant demonstrates that any act of the will involves our activity as intelligences. This includes action in accordance with hypothetical imperatives, which involves the capacity to understand what is required in order for us to influence the world and so act in it; it requires the capacity to act in accordance with laws. Kant characterizes his argument in Groundwork III as a deduction answering the question: With what right we are bound by the categorical imperative? It proceeds in three essential steps: an analysis of (1) negative freedom and the logical conditions of judgment in all practical principles; (2) moral valuation and the problem of the circle, and (3) positive freedom as implied in the act of reflection as the self understands itself as acting in accordance with the idea of laws. When we so act, we transfer ourselves into the world of intelligences and must assume the conditions of membership in such a world. These include being bound by the moral law.

This is an account of Kant’s understanding of the conditions of the possibility of willing in general. Kant’s definition of the will as “a capacity to act in accordance with the representation of laws” is analyzed at length, and I argue that this capacity is present not only in maxim-making but also in the making of judgments regarding how the world works imbedded in hypothetical imperatives. I provide a discussion of the nature of hypothetical imperatives, their relation to maxims, and their relation to the categorical imperative. The chapter concludes with a defense of Kant’s derivation of the categorical imperative from its mere concept, highlighting the central role played by the concept of autonomy in it. The upshot of this chapter is that the use of the higher faculty of intelligence must be present if the will is to operative at all.