Reason and Freedom of Choice

Despite all the Deontic elements, the source of concrete motivation in Kant's system is what he calls Willkur, i. e. Freedom of Choice.  Now, he acknowledges that disobeying his Categorical Imperative is possible, which seems to entail that Reason and Freedom are not co-extensive.  On the other hand,  Choice requires an object, and, so, is in fact subject to further influence, and, hence, is as such not Free.  But, it can choose Reason, for its own sake, and Reason is independent of external influences.  Hence, concrete Freedom consists in action that is motivated by Reason for its own sake, and it is only by virtue of the absolute privacy of the choosing that it might be classified as a Noumenal Cause. But, Aristotle and Spinoza are among those who define Reason differently than Kant.  So, many of the features of his Moral doctrine are inessential to the concept of Rational Ethics--notably the content of his Categorical Imperative, the Deontic Quantity of his Categorical Imperative, and the Noumenon vs. Phenomenon qua Freedom vs. Nature duality. Instead, a Rational Ethics that is independent of such trappings can thus be developed on the basis of Freedom of Choice, a concept of Reason, and choosing Reason for its own sake, with the latter the focal point.