Reading Aquinas on Evil: Is Evil in Good? (Q. 1, Art. 2)

In the First Article of Question One of the De Malo, which we examined in the previous post of this series, Aquinas concluded that evil is not an entity, i.e. it has no positive existence of its own; rather it is a privation or perversion of some good. We turn now to the Second Article, which asks: “Is There Evil in Good?” Aquinas answers in the affirmative.

Quoting Augustine, he declares that “there cannot be evil except in good” [1]. Expanding on this, he says:

“Evil is the privation of good . . . But privation limits its subject, for it is the negation of a form in a substance . . . Therefore, evil limits its subject. But every subject, as an existing thing, is good, since being and good are convertible terms. Therefore, evil is in good” [2].

In the previous article, Aquinas established that 1) good and being are equivalent, 2) hence evil and nonbeing are likewise equivalent, and so 3) evil is the privation/absence (nonbeing) of some good. But as I pointed out before, this does not mean that nonbeing in itself is evil. What is evil, rather, is some nonbeing that ought to be in existence but isn’t. As an example, I pointed out that the absence of wings on a human is not evil, but the absence of legs on a human would be an evil, since wings are not something that should exist on humans, whereas legs are, given human nature. Something that exists has a specific nature/essence with ends towards which it is intrinsically directed, as eyes are directed towards sight. These ends are the “good” of the thing; and the ends are again equivalent to form/being. What is evil is when these ends are frustrated/unfulfilled; so blindness is evil to an eye. But this implies that evil can only exist in some actually existing being. Evil is privation, and privation is “the negation of a form in a substance”. Blindness is evil because eyes are naturally directed towards the good of sight, and blindness deprives the eyes of this good. But blindness could hardly be a real condition, let alone an evil, apart from the eyes. Blindness can only be a real evil insofar as it is in the eyes. And since any substance in which evil would inhere as a privation is, by definition, a good, then evil can only exist in some good.

So this is Aquinas’s position, and now he explains/defends it more fully:

“Evil can only be in good. To prove this, we should note that we may speak of good in two ways: in one way of good absolutely; in the second way as we call a particular thing good, as, for example, we speak of a good man or a good eye. Therefore, when we speak of good absolutely, good has the greatest extension, even greater than being, as the Platonists held. For as good is something desirable, what is as such desirable is as such good and an end. And because we desire an end, we desire the means ordained for the end. Consequently, the means ordained for the end, from the very fact that they are ordained for the end or good, gain the nature of good. And so the useful is included within the classification of good. And everything that has potentiality for good, from the very fact that it has such potentiality, has an ordination to good, since having potentiality is simply being ordained for actuality. Therefore, whatever has potentiality, from the very fact that it does, evidently has the nature of good. Therefore, every subject, even prime matter, insofar as it has potentiality regarding any perfection, by that very fact has the nature of good. And the Platonists, since they failed to distinguish between matter and privation and classified matter with nonbeing, said that good has a greater extension than being” [3].

Similarly to how he distinguished different senses of evil in the previous article, Aquinas begins here by distinguishing different senses of good as well. One is a particular good, or some particular thing that is a good just insofar as good type of the particular thing it is; and the other is “good absolutely”, or we might say the general concept of goodness itself. Next he seems to make a somewhat inconsistent claim. In the prior quote, St. Thomas stated that “being and good are convertible terms”, and this has been a theme underlying both articles so far. But here he claims that good absolutely has “the greatest extension, even greater than being“. How can this be? One immediate answer is that when he speaks of being and good as convertible, he’s referring specifically to the first sense of good, i.e. particular good. As discussed in the previous post, goodness and being are equivalent in referent, but the concept of goodness considers being under the aspect of its desirability in terms of intrinsic, natural ends. So Aquinas says that “as good is something desirable, what is as such desirable is as such good and an end”. But because the good is a (naturally desired) end, and because ends often must be achieved by way of means, we also must desire these means. We do not desire the means for their own sake, but for the sake of the ends to which they are “ordained”; but still, insofar as those means are necessary to fulfill the ends, we desire those means. And since goodness is being considered under the aspect of its desirability, the means directed towards ends can likewise fall under the concept of good.

Furthermore, “everything that has potentiality for good, from the very fact that it has such potentiality, has an ordination to good, since having potentiality is simply being ordained for actuality”. A potentiality is always a potentiality for some actuality; it is intrinsically directed towards that actuality as to an end. But in that case, just as a means is good because and insofar as it is directed towards the good, potentiality itself must also be good, because it is intrinsically directed towards the good as to its end. Aquinas draws out the profound implications of this fact: “Every subject, even prime matter, insofar as it has potentiality regarding any perfection, by that very fact has the nature of good”. The reason this is such a profound conclusion is because Christianity had always stood in opposition to most of the rest of the ancient world in holding that the material in itself is inherently good. Most of the greeks had denied this, as had various Christian heretical offshoots such as Manichaeism which ensnared St. Augustine in his early life. Augustine leaned towards Manichaeism before his full conversion to Christianity because he thought it offered a solution to the problem of evil: if matter is inherently evil, then God does not “allow” evil (since they also held matter to be uncreated by God). Plato similarly thought that matter in itself is disordered and chaotic until it was ordered by the Divine Demiurge. But these doctrines require one to hold that there are aspects of reality outside of the creative and providential power and control of God. Matter exists eternally alongside God, and God is in constant struggle with it. The Christians, in contrast, unhesitatingly declared that all things were created by God, including matter; and hence that all things, insofar as they exist, are good. But St. Thomas takes matter to be equivalent to potentiality; and potentiality by definition is non-actual, not fully in being. But he argues here that we can still affirm even prime matter, pure, uninformed matter, as being good, insofar as it is directed towards being and goodness. But this means that good in the absolute sense has a broader concept than just being, because it includes not only what is actually in being but also what has potential for or is directed towards being.

He continues:

“And although we can call any being, whether actual or potential, good absolutely, nothing is by this very fact a particular good. For example, although human beings are good absolutely, it does not follow that they are good zither players; rather, they are good zither players when they have perfected the skill of zither-playing. Therefore, although human beings, by the very fact that they are human beings, are one kind of good, still they are not by that very fact good human beings; rather, it is the proper virtue of each thing that makes it good. For virtue makes its possessor good, as the Philosopher says in the Ethics. And virtue is a thing’s highest potentiality, as the On Heaven and Earth says. Therefore, we evidently call things particular goods when they have their proper perfection. For example, we call human beings good when they have the perfection proper to human beings, and eyes good when they have the perfection proper to eyes” [4].

So everything both actual and potential falls under good in the absolute sense. But just because something is good in the absolute sense, that does not make it a good in the particular sense. In the absolute sense, something is good just insofar as it exists (or has potential to exist). So a tree, qua tree, is good. But this does not mean that it is a good tree. For a tree to be a good tree, it must fulfill the perfective ends of its nature. Natures are intrinsically directed towards certain ends as their fulfillment and good; and so things are only good types of thing that they are insofar as they fulfill their natural ends. A bird that cannot fly is a good thing just insofar as it exists, but it is not a good bird, because it cannot fulfill its nature; it is “defective”. If we come across two triangles, one drawn with squiggly lines and the other with straight ones, we would conclude that the latter is a “better” triangle than the former. Both exist, and both are good insofar as they exist (i.e., it is good that they exist). But to be a triangle is to be a specific type of thing, and things that come closer to being that are better in relation to triangularity than things that fall short. So to be a particular good involves fulfilling the perfective ends of the nature of that particular thing. This is how we can affirm that all human beings are really good insofar as they exist and even insofar as they exist as human beings; and yet we can also admit that some human beings really are good human beings and some fall short of this, such as the wicked. In other words, this distinction in types of good allows us to say that some individual man is both good and evil at once, without succumbing to contradiction. In the previous post, we noted that evil in itself is a privation of good, but that we can designate things that are evil in which that privation inheres. So a man is good because he exists as a human being; but he can also be evil because he fails to properly fulfill his own human nature. This is what virtue is: whatever makes a particular kind of thing good/excellent at being what it is, is virtue. For humans, this is primarily moral character.

“Therefore, it is evident from the foregoing that we speak of good in three ways. For we in one way call the very perfection of a thing good, as, for example, we call accurate vision the eyes’ good, and virtue the good of human beings. In the second way, we call good the thing that has its proper perfection, as, for example, we call good human beings who are virtuous, and eyes that see accurately. In the third way, we call good the very subject as it has potentiality for perfection, as, for example, we call good the soul that has potentiality for virtue, and eyes that have potentiality for accurate vision. And as I have said before, evil is only the privation of a due perfection, and privation is only a potential being, since we say that things that nature designs to possess a perfection that they do not have are deprived. Therefore, it follows that there is evil in good, since we call potential beings good” [5].

Aquinas now expands to include three senses of good (it seems, however, on reflection, that Aquinas is talking about three senses of good specifically in relation to particular goods. In that case, there are actually four senses of good: good absolutely, and then three senses of particular good). The first is the “perfection” of a thing, the fulfillment of its natural ends. Sight is the good of the eyes. The second is the actual subject in which that perfection is fulfilled. So not only is sight the good of the eyes, but the eyes themselves that see are good. This second sense does not just refer to something as good insofar as it exists, but only to those existing things which have fulfilled their natural ends. There is thus a direct relation between the first and second senses of good; indeed we might even say that they can only be understood in relation to each other. The first is the good which is possessed, and the second is that which possesses the good, and is made good insofar as it possesses it. Virtue is good because it perfects a human; and a virtuous human is good because he is perfected by virtue. The third sense is also the subject, but the subject in which the perfections have not been fulfilled, but there still exists the potential for such. Sight is good in the first sense, eyes that see are good in the second, but the eyes themselves are good in the third sense, just insofar as they are able to see. Evil is the privation of good where good is considered as a natural perfection. It seems thus that evil affects all three senses of good: it is the privation of perfection, so good in the first sense is absent; and since good in the first two senses are co-dependent, where good in the first sense is absent, so is good in the second sense; but even further, it seems that in some cases evil actually deprives something of its very potential for that perfection, as blindness renders eyes physically incapable of sight. Aquinas hints at this:

“But evil deprives things of the good that is perfection. And so there cannot be evil in such a good. And evil lessens the good composed of a subject and its proper perfection insofar as the perfection is removed and the subject remains. For example, blindness takes away sight and lessens the eyes’ power of sight and belongs to the substance of the eyes and even to the very animal as the deprived subject” [6].

At first he notes that there cannot be evil in the good of perfection, since evil is just the complete absence of that good (there cannot be evil in sight; rather the evil is in the eyes which lacks sight, because it lacks sight). Evil is thus not in good in the first sense, but it still affects it in that it removes it. And it definitely affects good in the second sense, because it “lessens the good composed of a subject and its proper perfection”. But finally, he points out that in his example that blindness also “lessens the eyes’ power of sight”, i.e. its potential for the perfection of sight. The good that the evil is “in” is the substance whose perfections have been removed from it.

He concludes:

“And so if there is a good that is pure actuality, an actuality that has no mixture of potentiality—and God is such—there cannot in any way be evil in such a good” [7].

This statement calls for a little reflection. What is it that allows for evil to exist in beings? Evil exists in them insofar as those beings are deprived of their proper good. But how does this happen? If something has perfective ends which it seeks, this means that it has potencies which are directed towards the fulfillment of those ends. So evil is when these natural potencies are frustrated and prevented from realization. But a being that is pure actuality has no potencies which could possibly be frustrated/prevented from realization. It has no perfective ends that are not already fully actualized in itself. And thus, such a being is wholly good and there cannot in any way be evil in that being.In fact, Aquinas goes on to say, in a response to one of the objections, that “the good that is the subject of evil is a potentiality” [8]. What he means by this is that since evil is the privation of a perfection, and since potentiality is a good insofar it is ordained towards a perfection, potentiality is the subject of evil because evil deprives it of the perfections towards which it is directed. So a thing without any potentialities would have no subject in which evil could inhere. A thing without any potentiality whatsoever cannot even in principle admit of evil. A thing that has potentialities but has fulfilled them all will not actually admit in evil but could in principle. So Aquinas says in another reply:

“Both perfect things and those with potentiality for perfection have the nature of good. And there is evil in the latter kind of good” [9].

A thing is only “perfect” or perfected when it has fulfilled all its natural ends, and hence has no other potencies directed towards further perfections. Since there are no other potencies directed towards further perfections, there is nothing that can be frustrated/deprived. An eye that is perfectly seeing by definition has no blindness. Of course, something could happen to cause the eye to be deprived of its perfection, but in that case it would no longer be perfect.

And so we have concluded that evil exists in good (not in the sense of having positive existence of its own, since it is a privation, but in the sense of that privation being a privation of some end in a substance that is good), and indeed that evil could not be at all except in some actual good.



[1]. Aquinas, Thomas. On Evil. Translated by Richard Regan, edited by Brian Davies. New York: Oxford University Press, 2003. Q. 1, Art. 2, On the Contrary.

[2]. Ibid.

[3]. Ibid. Answer.

[4]. Ibid.

[5]. Ibid.

[6]. Ibid.

[7]. Ibid.

[8]. Ibid. Reply Obj. 10.

[9]. Ibid. Reply Obj. 14.

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