Summa Th. I EN Qu.48 a.2
Objection: 1. It would seem that evil is not found in things. For whatever is found in things, is either something, or a privation of something, that is a "not-being." But Dionysius says (Div. Nom. iv) that "evil is distant from existence, and even more distant from non-existence." Therefore evil is not at all found in things.
2. Further, "being" and "thing" are convertible. If therefore evil is a being in things, it follows that evil is a thing, which is contrary to what has been said (Article ).
3. Further, "the white unmixed with black is the most white," as the Philosopher says (Topic. iii, 4). Therefore also the good unmixed with evil is the greater good. But God makes always what is best, much more than nature does. Therefore in things made by God there is no evil.
On the contrary On the above assumptions, all prohibitions and penalties would cease, for they exist only for evils.
I answer that As was said above (Question , Articles ,2), the perfection of the universe requires that there should be inequality in things, so that every grade of goodness may be realized. Now, one grade of goodness is that of the good which cannot fail. 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.
As, therefore, the perfection of the universe requires that there should be not only beings incorruptible, but also corruptible beings; so the perfection of the universe requires that there should be some which can fail in goodness, and thence it follows that sometimes they do fail. Now it is in this that evil consists, namely, in the fact that a thing fails in goodness. Hence it is clear that evil is found in things, as corruption also is found; for corruption is itself an evil.
Reply to Objection: 1. Evil is distant both from simple being and from simple "not-being," because it is neither a habit nor a pure negation, but a privation.
2. As the Philosopher says (Metaph. v, text 14), being is twofold. In one way it is considered as signifying the entity of a thing, as divisible by the ten "predicaments"; and in that sense it is convertible with thing, and thus no privation is a being, and neither therefore is evil a being. In another sense being conveys the truth of a proposition which unites together subject and attribute by a copula, notified by this word "is"; and in this sense being is what answers to the question, "Does it exist?" and thus we speak of blindness as being in the eye; or of any other privation. In this way even evil can be called a being. Through ignorance of this distinction some, considering that things may be evil, or that evil is said to be in things, believed that evil was a positive thing in itself.
3. God and nature and any other agent make what is best in the whole, but not what is best in every single part, except in order to the whole, as was said above (Question , Article ). And the whole itself, which is the universe of creatures, is all the better and more perfect if some things in it can fail in goodness, and do sometimes fail, God not preventing this. This happens, firstly, because "it belongs to Providence not to destroy, but to save nature," as Dionysius says (Div. Nom. iv); but it belongs to nature that what may fail should sometimes fail; secondly, because, as Augustine says (Enchir. 11), "God is so powerful that He can even make good out of evil." Hence many good things would be taken away if God permitted no evil to exist; for fire would not be generated if air was not corrupted, nor would the life of a lion be preserved unless the ass were killed. Neither would avenging justice nor the patience of a sufferer be praised if there were no injustice.
Objection: 1. It would seem that evil is not in good as its subject. For good is something that exists. But Dionysius says (Div. Nom. iv, 4) that "evil does not exist, nor is it in that which exists." Therefore, evil is not in good as its subject.
2. Further, evil is not a being; whereas good is a being. But "non-being" does not require being as its subject. Therefore, neither does evil require good as its subject.
3. Further, one contrary is not the subject of another. But good and evil are contraries. Therefore, evil is not in good as in its subject.
4. Further, the subject of whiteness is called white. Therefore also the subject of evil is evil. If, therefore, evil is in good as in its subject, it follows that good is evil, against what is said (Is 5,20): "Woe to you who call evil good, and good evil!"
On the contrary Augustine says (Enchiridion 14) that "evil exists only in good."
I answer that As was said above (Article ), evil imports the absence of good. But not every absence of good is evil. For absence of good can be taken in a privative and in a negative sense. Absence of good, taken negatively, is not evil; otherwise, it would follow that what does not exist is evil, and also that everything would be evil, through not having the good belonging to something else; for instance, a man would be evil who had not the swiftness of the roe, or the strength of a lion. But the absence of good, taken in a privative sense, is an evil; as, for instance, the privation of sight is called blindness.
Now, the subject of privation and of form is one and the same---viz. being in potentiality, whether it be being in absolute potentiality, as primary matter, which is the subject of the substantial form, and of privation of the opposite form; or whether it be being in relative potentiality, and absolute actuality, as in the case of a transparent body, which is the subject both of darkness and light. It is, however, manifest that the form which makes a thing actual is a perfection and a good; and thus every actual being is a good; and likewise every potential being, as such, is a good, as having a relation to good. For as it has being in potentiality, so has it goodness in potentiality. Therefore, the subject of evil is good.
Reply to Objection: 1. Dionysius means that evil is not in existing things as a part, or as a natural property of any existing thing.
2. "Not-being," understood negatively, does not require a subject; but privation is negation in a subject, as the Philosopher says (Metaph. iv, text 4), and such "not-being" is an evil.
3. Evil is not in the good opposed to it as in its subject, but in some other good, for the subject of blindness is not "sight," but "animal." Yet, it appears, as Augustine says (Enchiridion 13), that the rule of dialectics here fails, where it is laid down that contraries cannot exist together. 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.
4. The prophet invokes woe to those who say that good as such is evil. But this does not follow from what is said above, as is clear from the explanation given.
Objection: 1. It would seem that evil corrupts the whole good. For one contrary is wholly corrupted by another. But good and evil are contraries. Therefore evil corrupts the whole good.
2. Further, Augustine says (Enchiridion 12) that "evil hurts inasmuch as it takes away good." But good is all of a piece and uniform. Therefore it is wholly taken away by evil.
3. Further, evil, as long as it lasts, hurts, and takes away good. But that from which something is always being removed, is at some time consumed, unless it is infinite, which cannot be said of any created good. Therefore evil wholly consumes good.
On the contrary Augustine says (Enchiridion 12) that "evil cannot wholly consume good."
I answer that Evil cannot wholly consume good. To prove this we must consider that good is threefold. One kind of good is wholly destroyed by evil, and this is the good opposed to evil, as light is wholly destroyed by darkness, and sight by blindness. Another kind of good is neither wholly destroyed nor diminished by evil, and that is the good which is the subject of evil; for by darkness the substance of the air is not injured. And there is also a kind of good which is diminished by evil, but is not wholly taken away; and this good is the aptitude of a subject to some actuality.
The diminution, however, of this kind of good is not to be considered by way of subtraction, as diminution in quantity, but rather by way of remission, as diminution in qualities and forms. The remission likewise of this habitude is to be taken as contrary to its intensity. For this kind of aptitude receives its intensity by the dispositions whereby the matter is prepared for actuality; which the more they are multiplied in the subject the more is it fitted to receive its perfection and form; and, on the contrary, it receives its remission by contrary dispositions which, the more they are multiplied in the matter, and the more they are intensified, the more is the potentiality remitted as regards the actuality.
Therefore, if contrary dispositions cannot be multiplied and intensified to infinity, but only to a certain limit, neither is the aforesaid aptitude diminished or remitted infinitely, as appears in the active and passive qualities of the elements; for coldness and humidity, whereby the aptitude of matter to the form of fire is diminished or remitted, cannot be infinitely multiplied. But if the contrary dispositions can be infinitely multiplied, the aforesaid aptitude is also infinitely diminished or remitted; yet, nevertheless, it is not wholly taken away, because its root always remains, which is the substance of the subject. 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." Yet the aforesaid aptitude of the soul is not wholly taken away, for it belongs to its very nature.
Reply to Objection: 1. The good which is opposed to evil is wholly taken away; but other goods are not wholly removed, as said above.
2. The aforesaid aptitude is a medium between subject and act. Hence, where it touches act, it is diminished by evil; but where it touches the subject, it remains as it was. Therefore, although good is like to itself, yet, on account of its relation to different things, it is not wholly, but only partially taken away.
3. Some, imagining that the diminution of this kind of good is like the diminution of quantity, said that just as the continuous is infinitely divisible, if the division be made in an ever same proportion (for instance, half of half, or a third of a third), so is it in the present case. But this explanation does not avail here. For when in a division we keep the same proportion, we continue to subtract less and less; for half of half is less than half of the whole. But a second sin does not necessarily diminish the above mentioned aptitude less than a preceding sin, but perchance either equally or more.
Therefore it must be said that, although this aptitude is a finite thing, still it may be so diminished infinitely, not "per se," but accidentally; according as the contrary dispositions are also increased infinitely, as explained above.
[*Pain here means "penalty": such was its original signification, being derived from "poena." In this sense we say "Pain of death, Pain of loss, Pain of sense."---Ed.]
Objection: 1. 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.
2. Further, in irrational creatures there is neither fault nor pain; but, nevertheless, they have corruption and defect, which are evils. Therefore not every evil is a pain or a fault.
3. Further, temptation is an evil, but it is not a fault; for "temptation which involves no consent, is not a sin, but an occasion for the exercise of virtue," as is said in a gloss on 2Co 12; not is it a pain; because temptation precedes the fault, and the pain follows afterwards. Therefore, evil is not sufficiently divided into pain and fault.
4. On the contrary, It would seem that this division is superfluous: for, as Augustine says (Enchiridion 12), a thing is evil "because it hurts." But whatever hurts is penal. Therefore every evil comes under pain.
I answer that Evil, as was said above (Article ) is the privation of good, which chiefly and of itself consists in perfection and act. Act, however, is twofold; first, and second. The first act is the form and integrity of a thing; the second act is its operation. Therefore evil also is twofold. In one way it occurs by the subtraction of the form, or of any part required for the integrity of the thing, as blindness is an evil, as also it is an evil to be wanting in any member of the body. In another way evil exists by the withdrawal of the due operation, either because it does not exist, or because it has not its due mode and order. But because good in itself is the object of the will, evil, which is the privation of good, is found in a special way in rational creatures which have a will. Therefore the evil which comes from the withdrawal of the form and integrity of the thing, has the nature of a pain; and especially so on the supposition that all things are subject to divine providence and justice, as was shown above (Question , Article ); for it is of the very nature of a pain to be against the will. But the evil which consists in the subtraction of the due operation in voluntary things has the nature of a fault; for this is imputed to anyone as a fault to fail as regards perfect action, of which he is master by the will. Therefore every evil in voluntary things is to be looked upon as a pain or a fault.
Reply to Objection: 1. Because evil is the privation of good, and not a mere negation, as was said above (Article ), therefore not every defect of good is an evil, but the defect of the good which is naturally due. For the want of sight is not an evil in a stone, but it is an evil in an animal; since it is against the nature of a stone to see. So, likewise, it is against the nature of a creature to be preserved in existence by itself, because existence and conservation come from one and the same source. Hence this kind of defect is not an evil as regards a creature.
2. Pain and fault do not divide evil absolutely considered, but evil that is found in voluntary things.
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.
4. In answer to the opposite argument, it must be said that the very nature of pain includes the idea of injury to the agent in himself, whereas the idea of fault includes the idea of injury to the agent in his operation; and thus both are contained in evil, as including the idea of injury.
Objection: 1. It would seem that pain has more of evil than fault. For fault is to pain what merit is to reward. But reward has more good than merit, as its end. Therefore pain has more evil in it than fault has.
2. Further, that is the greater evil which is opposed to the greater good. But pain, as was said above (Article ), is opposed to the good of the agent, while fault is opposed to the good of the action. Therefore, since the agent is better than the action, it seems that pain is worse than fault.
3. Further, the privation of the end is a pain consisting in forfeiting the vision of God; whereas the evil of fault is privation of the order to the end. Therefore pain is a greater evil than fault.
On the contrary A wise workman chooses a less evil in order to prevent a greater, as the surgeon cuts off a limb to save the whole body. But divine wisdom inflicts pain to prevent fault. Therefore fault is a greater evil than pain.
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.
There is a twofold reason for this. The first is that one becomes evil by the evil of fault, but not by the evil of pain, as Dionysius says (Div. Nom. iv): "To be punished is not an evil; but it is an evil to be made worthy of punishment." And this because, since good absolutely considered consists in act, and not in potentiality, and the ultimate act is operation, or the use of something possessed, it follows that the absolute good of man consists in good operation, or the good use of something possessed. Now we use all things by the act of the will. 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.
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. Therefore it is plain that fault has more evil in it than pain has.
Reply to Objection: 1. Although fault results in pain, as merit in reward, yet fault is not intended on account of the pain, as merit is for the reward; but rather, on the contrary, pain is brought about so that the fault may be avoided, and thus fault is worse than pain.
2. The order of action which is destroyed by fault is the more perfect good of the agent, since it is the second perfection, than the good taken away by pain, which is the first perfection.
3. Pain and fault are not to be compared as end and order to the end; because one may be deprived of both of these in some way, both by fault and by pain; by pain, accordingly as a man is removed from the end and from the order to the end; by fault, inasmuch as this privation belongs to the action which is not ordered to its due end.
We next inquire into the cause of evil. Concerning this there are three points of inquire:
(1) Whether good can be the cause of evil?
(2) Whether the supreme good, God, is the cause of evil?
(3) Whether there be any supreme evil, which is the first cause of all evils?
Objection: 1. It would seem that good cannot be the cause of evil. For it is said (Mt 7,18): "A good tree cannot bring forth evil fruit."
2. Further, one contrary cannot be the cause of another. But evil is the contrary to good. Therefore good cannot be the cause of evil.
3. Further, a deficient effect can proceed only from a deficient cause. But evil is a deficient effect. Therefore its cause, if it has one, is deficient. But everything deficient is an evil. Therefore the cause of evil can only be evil.
4. Further, Dionysius says (Div. Nom. iv) that evil has no cause. Therefore good is not the cause of evil.
On the contrary Augustine says (Contra Julian. i, 9): "There is no possible source of evil except good."
I answer that It must be said that every evil in some way has a cause. For evil is the absence of the good, which is natural and due to a thing. But that anything fail from its natural and due disposition can come only from some cause drawing it out of its proper disposition. For a heavy thing is not moved upwards except by some impelling force; nor does an agent fail in its action except from some impediment. But only good can be a cause; because nothing can be a cause except inasmuch as it is a being, and every being, as such, is good.
And if we consider the special kinds of causes, we see that the agent, the form, and the end, import some kind of perfection which belongs to the notion of good. Even matter, as a potentiality to good, has the nature of good. Now that good is the cause of evil by way of the material cause was shown above (Question , Article ). For it was shown that good is the subject of evil. But evil has no formal cause, rather is it a privation of form; likewise, neither has it a final cause, but rather is it a privation of order to the proper end; since not only the end has the nature of good, but also the useful, which is ordered to the end. Evil, however, has a cause by way of an agent, not directly, but accidentally.
In proof of this, we must know that evil is caused in the action otherwise than in the effect. In the action evil is caused by reason of the defect of some principle of action, either of the principal or the instrumental agent; thus the defect in the movement of an animal may happen by reason of the weakness of the motive power, as in the case of children, or by reason only of the ineptitude of the instrument, as in the lame. On the other hand, evil is caused in a thing, but not in the proper effect of the agent, sometimes by the power of the agent, sometimes by reason of a defect, either of the agent or of the matter. It is caused by reason of the power or perfection of the agent when there necessarily follows on the form intended by the agent the privation of another form; as, for instance, when on the form of fire there follows the privation of the form of air or of water. Therefore, as the more perfect the fire is in strength, so much the more perfectly does it impress its own form, so also the more perfectly does it corrupt the contrary. Hence that evil and corruption befall air and water comes from the perfection of the fire: but this is accidental; because fire does not aim at the privation of the form of water, but at the bringing in of its own form, though by doing this it also accidentally causes the other. But if there is a defect in the proper effect of the fire---as, for instance, that it fails to heat---this comes either by defect of the action, which implies the defect of some principle, as was said above, or by the indisposition of the matter, which does not receive the action of the fire, the agent. But this very fact that it is a deficient being is accidental to good to which of itself it belongs to act. Hence it is true that evil in no way has any but an accidental cause; and thus is good the cause of evil.
Reply to Objection: 1. As Augustine says (Contra Julian. i): "The Lord calls an evil will the evil tree, and a good will a good tree." Now, a good will does not produce a morally bad act, since it is from the good will itself that a moral act is judged to be good. Nevertheless the movement itself of an evil will is caused by the rational creature, which is good; and thus good is the cause of evil.
2. Good does not cause that evil which is contrary to itself, but some other evil: thus the goodness of the fire causes evil to the water, and man, good as to his nature, causes an act morally evil. And, as explained above (Question , Article ), this is by accident. Moreover, it does happen sometimes that one contrary causes another by accident: for instance, the exterior surrounding cold heats (the body) through the concentration of the inward heat.
3. Evil has a deficient cause in voluntary things otherwise than in natural things. For the natural agent produces the same kind of effect as it is itself, unless it is impeded by some exterior thing; and this amounts to some defect belonging to it. Hence evil never follows in the effect, unless some other evil pre-exists in the agent or in the matter, as was said above. But in voluntary things the defect of the action comes from the will actually deficient, inasmuch as it does not actually subject itself to its proper rule. This defect, however, is not a fault, but fault follows upon it from the fact that the will acts with this defect.
4. Evil has no direct cause, but only an accidental cause, as was said above.
Objection: 1. It would seem that the supreme good, God, is the cause of evil. For it is said (Is 45,5 Is 45,7): "I am the Lord, and there is no other God, forming the light, and creating darkness, making peace, and creating evil." And Amos 3:6, "Shall there be evil in a city, which the Lord hath not done?"
2. Further, the effect of the secondary cause is reduced to the first cause. But good is the cause of evil, as was said above (Article ). Therefore, since God is the cause of every good, as was shown above (Question , Article ; Question , Articles ,4), it follows that also every evil is from God.
3. Further, as is said by the Philosopher (Phys. ii, text 30), the cause of both safety and danger of the ship is the same. But God is the cause of the safety of all things. Therefore He is the cause of all perdition and of all evil.
On the contrary Augustine says (Questions. 83, qu. 21), that, "God is not the author of evil because He is not the cause of tending to not-being."
I answer that As appears from what was said (Article ), the evil which consists in the defect of action is always caused by the defect of the agent. But in God there is no defect, but the highest perfection, as was shown above (Question , Article ). Hence, the evil which consists in defect of action, or which is caused by defect of the agent, is not reduced to God as to its cause.
But the evil which consists in the corruption of some things is reduced to God as the cause. And this appears as regards both natural things and voluntary things. For it was said (Article ) that some agent inasmuch as it produces by its power a form to which follows corruption and defect, causes by its power that corruption and defect. But it is manifest that the form which God chiefly intends in things created is the good of the order of the universe. Now, the order of the universe requires, as was said above (Question , Article , ad 2; Question , Article ), that there should be some things that can, and do sometimes, fail. And thus God, by causing in things the good of the order of the universe, consequently and as it were by accident, causes the corruptions of things, according to 1S 2,6: "The Lord killeth and maketh alive." But when we read that "God hath not made death" (Sg 1,13), the sense is that God does not will death for its own sake. Nevertheless the order of justice belongs to the order of the universe; and this requires that penalty should be dealt out to sinners. And so God is the author of the evil which is penalty, but not of the evil which is fault, by reason of what is said above.
Reply to Objection: 1. These passages refer to the evil of penalty, and not to the evil of fault.
2. The effect of the deficient secondary cause is reduced to the first non-deficient cause as regards what it has of being and perfection, but not as regards what it has of defect; just as whatever there is of motion in the act of limping is caused by the motive power, whereas what there is of obliqueness in it does not come from the motive power, but from the curvature of the leg. And, likewise, whatever there is of being and action in a bad action, is reduced to God as the cause; whereas whatever defect is in it is not caused by God, but by the deficient secondary cause.
3. The sinking of a ship is attributed to the sailor as the cause, from the fact that he does not fulfil what the safety of the ship requires; but God does not fail in doing what is necessary for the safety of all. Hence there is no parity.
Objection: 1. It would seem that there is one supreme evil which is the cause of every evil. For contrary effects have contrary causes. But contrariety is found in things, according to Si 33,15: "Good is set against evil, and life against death; so also is the sinner against a just man." Therefore there are many contrary principles, one of good, the other of evil.
2. Further, if one contrary is in nature, so is the other. But the supreme good is in nature, and is the cause of every good, as was shown above (Question , Article ; Question , Articles ,4). Therefore, also, there is a supreme evil opposed to it as the cause of every evil.
3. Further, as we find good and better things, so we find evil and worse. But good and better are so considered in relation to what is best. Therefore evil and worse are so considered in relation to some supreme evil.
4. Further, everything participated is reduced to what is essential. But things which are evil among us are evil not essentially, but by participation. Therefore we must seek for some supreme essential evil, which is the cause of every evil.
5. Further, whatever is accidental is reduced to that which is "per se." But good is the accidental cause of evil. Therefore, we must suppose some supreme evil which is the "per se" cause of evils. Nor can it be said that evil has no "per se" cause, but only an accidental cause; for it would then follow that evil would not exist in the many, but only in the few.
6. Further, the evil of the effect is reduced to the evil of the cause; because the deficient effect comes from the deficient cause, as was said above (Articles ,2). But we cannot proceed to infinity in this matter. Therefore, we must suppose one first evil as the cause of every evil.
On the contrary The supreme good is the cause of every being, as was shown above (Question , Article ; Question , Article ). Therefore there cannot be any principle opposed to it as the cause of evils.
I answer that It appears from what precedes that there is no one first principle of evil, as there is one first principle of good.
First, indeed, because the first principle of good is essentially good, as was shown above (Question , Articles ,4). But nothing can be essentially bad. For it was shown above that every being, as such, is good (Question , Article ); and that evil can exist only in good as in its subject (Question , Article ).
Secondly, because the first principle of good is the highest and perfect good which pre-contains in itself all goodness, as shown above (Question , Article ). But there cannot be a supreme evil; because, as was shown above (Question , Article ), although evil always lessens good, yet it never wholly consumes it; and thus, while good ever remains, nothing can be wholly and perfectly bad. Therefore, the Philosopher says (Ethic. iv, 5) that "if the wholly evil could be, it would destroy itself"; because all good being destroyed (which it need be for something to be wholly evil), evil itself would be taken away, since its subject is good.
Thirdly, because the very nature of evil is against the idea of a first principle; both because every evil is caused by good, as was shown above (Article ), and because evil can be only an accidental cause, and thus it cannot be the first cause, for the accidental cause is subsequent to the direct cause.
Those, however, who upheld two first principles, one good and the other evil, fell into this error from the same cause, whence also arose other strange notions of the ancients; namely, because they failed to consider the universal cause of all being, and considered only the particular causes of particular effects. For on that account, if they found a thing hurtful to something by the power of its own nature, they thought that the very nature of that thing was evil; as, for instance, if one should say that the nature of fire was evil because it burnt the house of a poor man. The judgment, however, of the goodness of anything does not depend upon its order to any particular thing, but rather upon what it is in itself, and on its order to the whole universe, wherein every part has its own perfectly ordered place, as was said above (Question , Article , ad 1).
Likewise, because they found two contrary particular causes of two contrary particular effects, they did not know how to reduce these contrary particular causes to the universal common cause; and therefore they extended the contrariety of causes even to the first principles. But since all contraries agree in something common, it is necessary to search for one common cause for them above their own contrary proper causes; as above the contrary qualities of the elements exists the power of a heavenly body; and above all things that exist, no matter how, there exists one first principle of being, as was shown above (Question , Article ).
Reply to Objection: 1. Contraries agree in one genus, and they also agree in the nature of being; and therefore, although they have contrary particular cause, nevertheless we must come at last to one first common cause.
2. Privation and habit belong naturally to the same subject. Now the subject of privation is a being in potentiality, as was said above (Question , Article ). Hence, since evil is privation of good, as appears from what was said above (Question , Articles , 2,3), it is opposed to that good which has some potentiality, but not to the supreme good, who is pure act.
3. Increase in intensity is in proportion to the nature of a thing. And as the form is a perfection, so privation removes a perfection. Hence every form, perfection, and good is intensified by approach to the perfect term; but privation and evil by receding from that term. Hence a thing is not said to be evil and worse, by reason of access to the supreme evil, in the same way as it is said to be good and better, by reason of access to the supreme good.
4. No being is called evil by participation, but by privation of participation. Hence it is not necessary to reduce it to any essential evil.
5. Evil can only have an accidental cause, as was shown above (Article ). Hence reduction to any 'per se' cause of evil is impossible. And to say that evil is in the greater number is simply false. For things which are generated and corrupted, in which alone can there be natural evil, are the smaller part of the whole universe. And again, in every species the defect of nature is in the smaller number. In man alone does evil appear as in the greater number; because the good of man as regards the senses is not the good of man as man---that is, in regard to reason; and more men seek good in regard to the senses than good according to reason.
6. In the causes of evil we do not proceed to infinity, but reduce all evils to some good cause, whence evil follows accidentally.
Summa Th. I EN Qu.48 a.2