DEFINITION OF PRIMARY AND SECONDARY EVIL.
In short, the primary Evil is that which by itself lacks measure. The secondary evil is that which accidentally becomes formless, either by assimilation or participation. In the front rank is the darkness; in the second that which has become obscured. Thus vice, being in the soul the result of ignorance and formlessness, is of secondary rank. It is not absolute Evil, because, on its side, virtue is not absolute Good; it is good only by its assimilation and participation with the Good.
B. BY WHAT PART OF OUR NATURE WE COME TO KNOW EVIL.
HOW THE SOUL COMES TO KNOW VICE.[184]
9. How do we get to know vice and virtue? As to virtue, we know it by the very intelligence and by wisdom; for wisdom knows itself. But how can we know vice? Just as we observe that an object is not in itself straight, by applying a rule, so we discern vice by this characteristic, that it does not comport itself with virtue. But do we, or do we not have direct intuition thereof? We do not have the intuition of absolute vice, because it is indeterminate. We know it, therefore, by a kind of abstraction, observing that virtue is entirely lacking. We cognize relative vice by noticing that it lacks some part of virtue. We see a part of virtue, and, by this part, judging what is lacking in order completely to constitute the form (of virtue), we call vice what is lacking to it; defining as the indeterminate (evil) what is deprived of virtue. Similarly with matter. If, for instance, we notice a figure that is ugly because its ("seminal) reason," being unable to dominate matter, has been unable to hide its deformity, we notice ugliness by what is lacking to form.