But even though reason in its merely speculative use is far from ade quate for such a great aim as this namely, attaining to the existence of a supreme being it still has in them a very great utility, that of frecting the cognition of this being by making it agree with itself and with every intelligible aim, and by purifYing it of everything that might be incompatible with the concept of an original being, and of all ad mixture of empirical limitations.