Political Freedom and Psychological Freedom

Perhaps Kant's most important contribution to Modern Political Philosophy is rarely recognized as such--an implicit critique of the prevailing concept of 'freedom'.  According to that concept, one is 'free' when one's conduct is not subject to the will of another.  In contrast, according to Kant, Freedom is, most fundamentally, a psychological condition that entails mastery of one's impulses.  Thus, mere political 'freedom' is neither a necessary or a sufficient condition of psychological Freedom.  In other words, for example, the 'pursuit of happiness', a treasured 'freedom' in the U. S., can consist in conditioned, i. e. unfree, behavior.