Thomas Aquinas

“ Thus, therefore, the evil which is a constitutive difference in morals is a certain good joined to the privation of another good; as the end proposed by the intemperate man is not the privation of the good of reason, but the delight of sense without the order of reason. Hence evil is not a constitutive difference as such, but by reason of the good that is annexed. ”

“ Hence from a good will, which makes a man use well what he has, man is called good, and from a bad will he is called bad. For a man who has a bad will can use ill even the good he has, as when a grammarian of his own will speaks incorrectly. Therefore, because the fault itself consists in the disordered act of the will, and the pain consists in the privation of something used by the will, fault has more of evil in it than pain has. ”

“ A thing is said to act in a threefold sense. In one way, formally, as when we say that whiteness makes white; and in that sense evil considered even as a privation is said to corrupt good, forasmuch as it is itself a corruption or privation of good. In another sense a thing is said to act effectively, as when a painter makes a wall white. ”

“ For the Philosopher speaks there of good and evil in morality. Because in that respect, between good and evil there is a medium, as good is considered as something rightly ordered, and evil as a thing not only out of right order, but also as injurious to another. Hence the Philosopher says (Ethic. iv, i) that a "prodigal man is foolish, but not evil." And from this evil in morality, there may be a return to good, but not from any sort of evil, for from blindness there is no return to sight, although blindness is an evil. ”

“ I answer that, Fault has the nature of evil more than pain has; not only more than pain of sense, consisting in the privation of corporeal goods, which kind of pain appeals to most men; but also more than any kind of pain, thus taking pain in its most general meaning, so as to include privation of grace or glory. ”

“ The second reason can be taken from the fact that God is the author of the evil of pain, but not of the evil of fault. And this is because the evil of pain takes away the creature's good, which may be either something created, as sight, destroyed by blindness, or something uncreated, as by being deprived of the vision of God, the creature forfeits its uncreated good. But the evil of fault is properly opposed to uncreated good; for it is opposed to the fulfilment of the divine will, and to divine love, whereby the divine good is loved for itself, and not only as shared by the creature. ”

“ It would seem that evil is not adequately divided into pain and fault. For every defect is a kind of evil. But in all creatures there is the defect of not being able to preserve their own existence, which nevertheless is neither a pain nor a fault. Therefore evil is inadequately divided into pain and fault. ”

“ Another grade of goodness is that of the good which can fail in goodness, and this grade is to be found in existence itself; for some things there are which cannot lose their existence as incorruptible things, while some there are which can lose it, as things corruptible. ”

“ Thus, if opaque bodies were interposed to infinity between the sun and the air, the aptitude of the air to light would be infinitely diminished, but still it would never be wholly removed while the air remained, which in its very nature is transparent. Likewise, addition in sin can be made to infinitude, whereby the aptitude of the soul to grace is more and more lessened; and these sins, indeed, are like obstacles interposed between us and God, according to Is. 59:2: "Our sins have divided between us and God." ”

“ Pain and fault do not divide evil absolutely considered, but evil that is found in voluntary things.
Reply to Objection 3: Temptation, as importing provocation to evil, is always an evil of fault in the tempter; but in the one tempted it is not, properly speaking, a fault; unless through the temptation some change is wrought in the one who is tempted; for thus is the action of the agent in the patient. And if the tempted is changed to evil by the tempter he falls into fault. ”

“ But this is to be taken as referring to good and evil in general, but not in reference to any particular good and evil. For white and black, sweet and bitter, and the like contraries, are only considered as contraries in a special sense, because they exist in some determinate genus; whereas good enters into every genus. Hence one good can coexist with the privation of another good. ”

“ Yet neither does the absence of the due end by itself constitute a moral species, except as it is joined to the undue end; just as we do not find the privation of the substantial form in natural things, unless it is joined to another form. ”