Reason, Consistency, Sufficiency

Kant's concept of 'imperfect duty' is a challenge to his thesis that 'rational' conduct is governed primarily by Consistency, since it requires him to explain how something that does not exist, i. e. a non-performed act, entails a contradiction.  Accordingly, he concocts maxims of impulsive negligence to serve as the bearers of inconsistency.  He thereby circumvents examination of the possibility that conduct can be 'rational' by virtue of maxims that are derived not from impulse, but from Reason itself.  In such cases, Reason is governed by what has here been previously termed a 'Principle of Practical Sufficient Reason', in which Reason is itself creative.  On that basis, Consistency is only a necessary condition of the Rationality of conduct.