pure reason can be of itself practical without the aid of any spring of action that could be derived from any other source, i.e., how the mere principle of the universal validity of all its maxims as laws (which would certainly be the form of a pure practical reason) can of itself supply a spring, without any matter (object) of the will in which one could antecedently take any interest; and how it can produce an interest which would be called purely moral; or in other words, how pure reason can be practical- to explain this is beyond the power of human reason, and all the labour and pains of seeking an explanation of it are loSt. It is just the same as if I sought to find out how freedom itself is possible as the causality of a will.

For then I quit the ground of philosophical explanation, and I have no