Kant holds that the applicability of the moral 'ought' depends on a kind of agent-causal freedom that is incompatible with the deterministic structure of phenomenal nature. I argue that Kant understands this determinism to threaten not just morality but the very possibility of our status as rational beings. Rational beings exemplify "cognitive control" in all of their actions, including not just rational willing and the formation of doxastic attitudes, but also more basic cognitive acts such as judging, conceptualizing, and synthesizing. Considered merely as intelligence, a human being is an imputable subject in which, of course, at the same time is united a natural being that subjects it to natural laws; [a being] nevertheless, whose determination depends upon intelligence, insofar as the possibility to act is granted him; therefore it is only to be derived how far a human being can be called cause of his actions and these can be imputed to him; and [it is] just as certain that, if he were led merely by natural laws, it would be impossible to impute to him any action, since the ground of action then would never lie in his control, but rather would be determined in the previous time.