Distributive Reason and the Principle of Pure Practical Reason

Kant's principle of Pure Practical Reason is, to all known appearances, unprecedented, i. e. there is no evidence that it antedates him.  Thus, his formulation either makes explicit what is eternally implicit, culminates recent intellectual developments, or is simply an untimely product of genius--his own theory of History seems to suggest that he himself subscribes to the second hypothesis.  In any case, as a novel phenomenon, that he clearly projects as universally applicable, the principle is a product of example-setting Distributive Reason.