An inclination is relevant in practical reason because its object is desirable, not because the inclination is naturally widespread.

Many modern accounts of Aquinas’ theory of natural law give explanatory primacy to the naturalness of the inclinations (to live, to know, etc.) that correspond to these basic goods. But others regard this as a fundamental misunderstanding of Aquinas’ conception of will, and of the epistemological relationship between nature and reason. Will is for him intelligent response to intelligible good: one’s will is “in” one’s reason [voluntas in ratione]. He makes it very explicit both that human action