Summa contra Gentiles3.8 Chapter VIII and IX. Arguments whereby seemingly it is proved that evil is a nature or a thing

It would seem that certain arguments militate against the aforesaid statement.

For each thing derives its species from its proper difference. Now evil is a specific difference in certain genera, namely in moral habits and acts: because as virtue according to its species is a good habit, so the contrary vice is an evil habit according to its species: and the same applies to virtuous and viciousacts. Therefore evil gives certain things their species. Therefore it is an essence, and is natural to certain things.

Further. Each of two contraries is a nature: for if it predicated nothing, one of the contraries would be a pure privation or negation. But good and evil are stated to be contraries. Therefore evil is a nature.

Again. Aristotle in his Predicaments (Categor. viii. 27) says that good and evil are the genera of contraries. Now every genus has an essence or nature: for there are no species or differences of non-being, so that what is not cannot be a genus. Therefore evil is an essence anda nature. Also. Whatever is active is a thing. Now evil as such is active: for it counteracts and corrupts good. Therefore evil as such is a thing.

Moreover. Whatever can be more or less must be a thing admitting of degrees: since negations and privations do not admit of being more or less. Now among evils we find one to be worse than another. Therefore seemingly, evil must be a thing.

Furthermore. Thing and being are convertible terms. Now evil existsin the world. Therefore it isa thing and anature. Til 2 ‘These objections, however, are easily solved. For evil and good in morals are said to be specific differences, as the first argument stated, because morality depends on the will: for a thing comes under the head of morals so far as it is voluntary. Now the will’s object is the end and the good. Hence moral matters are specified by their end: even as natural actions are by the form of their active principle, for instance, the action of heating is specified by heat. Since then good and evil are predicated in respect of the universal direction to an end, or the privation of that direction, it follows that in morals the first difference is that of good and evil. Now for one genus there must be one first measure: and the measure in morals is reason. Consequently good and evil in moral matters must depend on the end appointed by reason. Accordingly, in morals, that which derives its species from an end that is in accord with reason, is said to be specifically good: and that which derives its species from an end discordant from reason, is said to be specifically bad. And yet this end, though it sets aside the end appointed by reason, is nevertheless some kind of good, such as a pleasurable object of the senses, or something similar, so that in some animals this end is good, and even in man when it is moderated by reason. Also it happens that what is evil for one, is good for another. Wherefore evil, so far as it is a specific difference in the moral genus, does not denote a thing essentially evil; but something that is good in itself, but evil for man, in so far as it removes the order of reason, which isman’s good, From this it follows that evil and good are contraries forasmuch as they are applied to the moral genus; and not in their absolute signification, as the second objection stated: but evil, as such, is a privation of good.

In the same way we may understand the saying that evil and good, taken in the moral order, are the genera of contvaries, on which the third objection was based. For of all moral contraries, either both are evil, as prodigality and stinginess; or one is good and the other evil, as liberality and stinginess. Hence moral evil is both a genus and a differ-by reason, whence it is called evil, but through the nature of the action or habit that is directed to an end incompatible with the right end appointed by reason: thus a blind man is a human individual, not as being blind, but as being this particular man: and irrational is a difference of animal, not through the privation of reason, but on account of this particular nature to which privation of reason is consequent. It may also be said that Aristotle asserts evil and good to be genera, not in his own opinion, since he does not number them among the ten first genera in each of which some contrariety is found, but according to the opinion of Pythagoras, who affirmed that good and evil are supreme genera and first principles. Under each of them he placed ten supreme contraries: so that we have the good which is definite, which is equal, which is one, which is on the right hand, the male, the vestful, the straight, the luminous, the square, and lastly, the good: while under evil jhe placed the indefinite, the unequal, the manifold, the left-hand, the female, the moving, the crooked, the darksome, the oblong, and lastly, the evil. In this way and in several passages of his works on logic, he employs examples according to the opinions of other philosophers, as being probable at the time.

Moreover this saying contains a certain amount of truth:

utterly false. Now of all contraries one is perfect, while the other is incomplete, as containing some kind of privation: thus white and hot are perfect, while cold and black are imperfect, as indicating a kind of privation. Since then incompleteness and privation are a kind of evil, while every perfection and completeness comes under the head of good: it follows that in contraries, one seems to be comprised under good, while the other approaches to the notion of evil. In In this way too it is clear how evil is opposed to good, which was the line taken by the fourth objection. Because in so far as form and end, which have the aspect of good, and are the true principles of action, involve privation of a contrary form and end, the action that is consequent upon this form and end, is ascribed to privation and evil: accidentally however, since privation, as such, is not a principle of action. Rightly therefore does Dionysius say (De Div. Nom. iv.) that evil does not oppose good, except by virtue of a good: and in itself it is powerless and weak, as not being a principle of action. Evil, however, is said to corrupt good, not only as acting by virtue of a good, as explained: but formally by—itself; even as blindness is said to corrupt the sight, through being the very corruption of sight: in the same way whiteness is said to colour the wall, because it is the very colour of the wall.

A thing is said to be a greater or lesser evil by reason of its distance from the good. For thus it is that things which imply privation admit of degrees, as imequality and unlikeness: thus to be more unequal is to be more distant from equality: and to be more unlike is to go further from likeness.

Wherefore that is said to be more evil, which is more deprived of good, as being more distant from good. But privations are subject to increase not as having a kind of essence, as qualities and forms, as the fifth argument presumed, but through the increase of the cause of privation: thus air is more darksome, according as the light is impeded by the interposition of more obstacles, for thus it is further removed from a participation of light.

Again evil is said to be in the world, not as though it had an essence, or were some thing, as the sixth argument supposed, but forasmuch as a thing is said to be evil with evil: even as blindness and privation of any kind is said to be, because an animal is blind with blindness.

For being is predicated in two. ways, as the Philosopher teaches (4 Metaph. vii.). First as indicating the essence of a thing; and thus it is divided into the ten categories: in this way no privation can be called a being. Secondly as denoting a synthetical truth: in this way evil and privation are called a being, forasmuch as a ie is said to be deprived by a privation.