490. X. THAT ADULTERIES OF THE THIRD DEGREE ARE ADULTERIES FROM THE REASON, WHICH ARE COMMITTED BY THOSE WHO BY THEIR UNDERSTANDING CONFIRM THEM AS NOT BEING EVILS OF SIN. Every man knows that there is will and understanding, for when he speaks he says, This I will, and This I understand. Still, he does not distinguish between them but makes the one the same as the other. The reason is because he reflects only upon those things which pertain to thought from the understanding, and not upon those which pertain to love from the will; for the latter, unlike the former, do not appear in light. Yet he who does not distinguish between will and understanding cannot distinguish between evil things and good, and so can know nothing whatever concerning blame for sin. But who does not know that good and truth are two distinct things like love and wisdom? and who, when in rational lumen, cannot conclude from this that there are two vessels in man which distinctly receive these and ascribe them to themselves? and that one is the will and the other the understanding? and this because that which the will receives and reproduces is called good, and that which the understanding receives is called truth, what the will loves and does being called good, and what the understanding perceives and thinks being called truth.
 Since the marriage of good and truth was treated of in the first part of this work; and since much was there adduced concerning will and understanding and the various attributes and predicates of each, which, I suppose, is perceived even by those who have had no distinct thought concerning understanding and will--human reason being such that it perceives truths from the light of truths even though it has not previously distinguished between them--therefore, in order that the distinction between will and understanding may be perceived more distinctly, to the end that the nature of adulteries from reason or understanding may be known, and after that the nature of adulteries from the will, I will here present something further.  The following may serve for a knowledge concerning will and understanding: 1. That the will alone does nothing of itself, but whatever it does it does by the understanding. 2. On the other hand, the understanding alone does nothing of itself, but whatever it does it does from the will. 3. That the will flows into the understanding, not the understanding into the will. But the understanding teaches what is good and evil, and consults the will that the latter may choose which of the two is pleasing to it and may do it. 4. That after this a twofold conjunction is effected, one in which the will act from within and the understanding from without, the other in which the understanding acts from within and the will from without.
Thus the adulteries from reason here treated of are distinguished from adulteries from will, of which hereafter. They are distinguished because the one is more grievous than the other, adultery from reason being less grievous than adultery from will. In adultery from reason, the understanding acts from within and the will from without, while in adultery from will, the will acts from within and the understanding from without--the will being the man himself, and the understanding the man from the will--and that which acts within dominates over that which acts without.