The Cloud of Unknowing, ed. by Evelyn Underhill, , at sacred-texts.com
Of the other two principal powers Reason and Will; and of the work of them before sin and after.
REASON is a power through the which we depart the evil from the good, the evil from the worse, the good from the better, the worse from the worst, the better from the best. Before ere man sinned, might Reason have done all this by nature. But now it is so blinded with the original sin, that it may not con work this work, unless it be illumined by grace. And both the self Reason, and the thing that it worketh in, be comprehended and contained in the Memory.
Will is a power through the which we choose good, after that it be determined p. 279 with Reason; and through the which we love good, we desire good, and rest us with full liking and consent endlessly in God. Before ere man sinned, might not Will be deceived in his choosing, in his loving, nor in none of his works. For why, it had then by nature to savour each thing as it was; but now it may not do so, unless it be anointed with grace. For ofttimes because of infection of the original sin, it savoureth a thing for good that is full evil, and that hath but the likeness of good. And both the Will and the thing that is willed, the Memory containeth and comprehendeth in it. p. 280