No More Learning

Now, this objective reality of a pure concept of the understanding in the sphere of the supersensible, once brought in, gives an objec- tive reality also to all the other categories,           only so far as they stand in necessary connexion with the determining principle of the will (the moral law); a reality only of practical application, which has not the least effect in enlarging our theoretical knowl- edge of these objects, or the discernment of their nature by pure
Immanuel Kant
57
The Critique of Practical Reason
reason.