Groundwork of the Metaphysics of Morals

Kant routinely grapples with the idea of free will in a way that readers may find confusing. After establishing the importance of an autonomous will in the Second Section, he begins the Third Section by claiming that examining a “positive concept of freedom” will yield a line of inquiry that is “so much the richer and more fruitful” (56, 4:447). Positive freedom describes what we are free to do, whereas negative freedom describes what we are free from doing. Since Kant eventually offers a theory of morality that is based on making an active choice to act in a given way, it makes sense he would begin by focusing on an action-oriented definition of freedom.

Kant acknowledges that many of his readers will initially find his connection between morality and free will circular, writing:

We take ourselves to be free in the order efficient causes so as to think ourselves under moral laws in the order of ends, and we afterwards think ourselves as subject to these laws because we have ascribed to ourselves freedom of the will; for freedom and the will’s own legislation are both autonomy, and hence reciprocal concepts; but precisely because of this one of them cannot be used to explicate the other or to state its ground, but at most only to reduce to a single concepts, for logical purposes, representations of just the same object that appear dissimilar [.