That the contrary propensities in good and bad angels have arisen, not from a difference in their nature and origin, since God, the good Author and Creator of all essences, created them both, but from a difference in their wills and desires, it is impossible to doubt. While some steadfastly continued in that which was the common good of all, namely, in God Himself, and in His eternity, truth, and love; others, being enamored rather of their own power, as if they could be their own good, lapsed to this private good of their own, from that higher and beatific good which was common to all, and, bartering the lofty dignity of eternity for the inflation of pride, the most assured verity for the slyness of vanity, uniting love for factious partisanship, they became proud, deceived, envious. The cause, therefore, of the blessedness of the good is adherence to God. And so the cause of the others' misery will be found in the contrary, that is, in their not adhering to God. Wherefore, if when the question is asked, why are the former blessed, it is rightly answered, because they adhere to God; and when it is asked, why are the latter miserable, it is rightly answered, because they do not adhere to God, -- then there is no other good for the rational or intellectual creature save God only. Thus, though it is not every creature that can be blessed (for beasts, trees, stones, and things of that kind have not this capacity), yet that creature which has the capacity cannot be blessed of itself, since it is created out of nothing, but only by Him by whom it has been created. For it is blessed by the possession of that whose loss makes it miserable. He, then, who is blessed not in another, but in himself, cannot be miserable, because he cannot lose himself.
Accordingly we say that there is no unchangeable good but the one, true, blessed God; that the things which He made are indeed good because from Him, yet mutable because made not out of Him, but out of nothing. Although, therefore, they are not the supreme good, for God is a greater good, yet those mutable things which can adhere to the immutable good, and so be blessed, are very good; for so completely is He their good, that without Him they cannot but be wretched. And the other created things in the universe are not better on this account, that they cannot be miserable. For no one would say that the other members of the body are superior to the eyes, because they cannot be blind. But as the sentient nature, even when it feels pain, is superior to the stony, which can feel none, so the rational nature, even when wretched, is more excellent than that which lacks reason or feeling, and can therefore experience no misery. And since this is so, then in this nature which has been created so excellent, that though it be mutable itself, it can yet secure its blessedness by adhering to the immutable good, the supreme God; and since it is not satisfied unless it be perfectly blessed, and cannot be thus blessed save in God, -- in this nature, I say, not to adhere to God, is manifestly a fault.  Now every fault injures the nature, and is consequently contrary to the nature. The creature, therefore, which cleaves to God, differs from those who do not, not by nature, but by fault; and yet by this very fault the nature itself is proved to be very noble and admirable. For that nature is certainly praised, the fault of which is justly blamed. For we justly blame the fault because it mars the praiseworthy nature. As, then, when we say that blindness is a defect of the eyes, we prove that sight belongs to the nature of the eyes; and when we say that deafness is a defect of the ears, hearing is thereby proved to belong to their nature; -- so, when we say that it is a fault of the angelic creature that it does not cleave to God, we hereby most plainly declare that it pertained to its nature to cleave to God. And who can worthily conceive or express how great a glory that is, to cleave to God, so as to live to Him, to draw wisdom from Him, to delight in Him, and to enjoy this so great good, without death, error, or grief? And thus, since every vice is an injury of the nature, that very vice of the wicked angels, their departure from God, is sufficient proof that God created their nature so good, that it is an injury to it not to be with God.
 Vitium: perhaps "fault," most nearly embraces all the uses of this word.