188. The Privation Theory of Evil, Part 1


In the previous post I presented some contemporary scientific views on evil and argued both for their importance and their limitations. We saw that such views can be construed as natural evil insofar as they see evil as a non-moral catastrophe, illness, or malfunction of some kind that results in suffering. As a result they leave out moral evil that entails free will, choice, responsibility, guilt, sin, and so on. In the following series of posts I would like to present and defend a theory that can account for both these forms of evil and more, namely, the privation theory of evil. The privation theory is one of the oldest and most influential philosophical theories of evil. It has its roots in Plato (427-347 BC) and Aristotle (384-322 BC), is given an extreme interpretation by Plotinus (circa 204-270 CE), and subsequently finds its most influential mode of exposition in St. Augustine (354-430 CE) and St. Thomas Aquinas (1225-1274 CE). According to this theory, evil does not exist as a thing or property of a thing. Rather, evil is some sort of deficiency or privation of some good that, by nature, should be present. In this post I will give a brief overview of the theory with the help of various thinkers. In the second post I will present and respond to various objections to the theory. And in the third and final post I will present a set of positive reasons to embrace the theory. I will conclude that these reasons, when taken together, suggest the privation theory, although rejected by many contemporary philosophers, should be a viable option for both defining and explaining various types of evil. 

Early Notions of Privation: Plato, Aristotle, and Plotinus

Let’s begin with some insights from three figures who helped lay the groundwork for the privation theory of evil. After doing so, we will consider the more influential formulations in Augustine and Aquinas before moving to a convincing contemporary formulation.


One idea suggested in various places in Plato’s dialogues is that the physical world is an imperfect imitation of the immaterial, eternal, and perfect Ideas or Forms. And this imperfection implies that privations are built into nature: things fall short of what they, by nature, should be. For example, every physical circle, by virtue of being physical, falls short of, is deprived of, the full essence that the perfect Form of circularity possesses (no physical circle actually has all points equidistant from the center). These privations would be forms of what G.W. Leibniz would later, in his book Theodicy (see “Essays on the Justice of God and the Freedom of Man in the Origin of Evil”, Part One, section 21), call metaphysical evil or evil as ontological limitation, that is, limitation in terms of reality or being. Harold Cherniss, in his excellent article “The Sources of Evil According to Plato”, elaborates: “the phenomenal world is a spatial reflection of the ideas, which alone are perfectly real entities. Since no copy or reflection can be identical with its model or original, all phenomena must fall short of the reality of the ideas, and all must therefore be something less than perfect. So all the phenomenal world is always involved in what might be called “negative evil,” since it is a derogation of reality, the degree of deviation from the original which at the very least is implied in the existence of a copy or reflection.” 

The limitations of metaphysical evil contribute to the non-moral suffering that marks natural evil. In Plato’s dialogue Timaeus (43c, translation Benjamin Jowett) we learn that the imperfect physical world, rather than completely following the measure and harmony of the divine realm of the ideas, falls short of it and includes elements of radical chaos. We also learn that once human souls were fastened to bodies they were placed in the wild stream of this physical world where “the affections produced by external contact caused still greater tumult when the body of any one met and came into collision with some external fire, or with the solid earth or the gliding waters, or was caught in the tempest borne on the air, and the motions produced by any of these impulses were carried through the body to the soul.” These collisions cause us suffering. But they also compromise the functions of the soul: “If, when powerfully experiencing these and similar effects, the revolutions of the soul come in contact with some external thing, either of the class of the same or of the other, they speak of the same or of the other in a manner the very opposite of the truth; and they become false and foolish, and there is no course or revolution in them which has a guiding or directing power; and if again any sensations enter in violently from without and drag after them the whole vessel of the soul, then the courses of the soul, though they seem to conquer, are really conquered.” Thus we see that the effects of the unruly physical world on our souls can lead to falsehood and foolishness: privations of knowledge and virtue that lead people to pursue fleeting bodily pleasures among the reflections of the ideas rather than pursue wisdom by seeking to grasp the ideas themselves. Here is Cherniss again: 

“It follows that the soul, in ignorance or forgetfulness of the true nature of the ideas and especially of the relation obtaining between any of them and the idea of the good, must cause evil in whatever part of the phenomenal world it affects by its motion, for it will misarrange the reflections of reality and may in its error even come to regard as real and take for the patterns of its action these spatial reflections themselves instead of their originals.”

Plato writes of this ignorance and its relation to evil in his dialogue Protagoras: “When people make a wrong choice of pleasures and pains – that, of good and evil – the cause of their mistake is lack of knowledge” (357d, translation Guthrie). Of course such misguided action, if it is completely a function of ignorance, might also be construed as natural evil for which no one is responsible. There are passages in Plato that support this reading. For example, at Timaeus (86b3, translated by R. G. Bury) we read: “We must agree that folly is a disease of the soul; and of folly there are two kinds, the one of which is madness, the other ignorance. Whatever affection a man suffers from, if it involves either of these conditions it must be termed “disease”; and we must maintain that pleasures and pains in excess are the greatest of the soul’s diseases.” And in many cases people are not morally responsible for getting a disease.

But Plato also appears to endorse moral evil, or evil which is the effect of free will and responsible agency, in other places like Republic 617e (translated by Cornford): “But Virtue owns no master: as a man dishonors or dishonours her, so shall he have more or less. The blame is his who chooses; Heaven is blameless.” And we learn that choices that lead to evil are made in part because of thoughtlessness. For example, at the end of Republic (619, translation Cornford) Plato depicts a soul that thoughtlessly chooses to be tyrant in his next life and is blamed for his actions: “In his thoughtless greed he was not careful to examine the life he chose at every point, and he did not see the many evils it contained and that he was fated to devour his own children; but when the time came to look more closely, he began to beat his breast and bewail his choice, forgetting the warning proclaimed by the Interpreter; for he laid blame on fortune, the decrees of the gods, anything rather than himself.” And this all occurred because he became virtuous merely “from habit without pursuing wisdom.” This emphasis on choice allows us to see how there is evidence of moral evil in Plato as well.

We can conclude this brief overview by noting how all three forms of evil relate: we wouldn’t have the opportunity for immoral choices if we didn’t have, on the one hand, metaphysical evil or a world full of privations that falls terribly short of the perfect model upon which it is based and, on the other hand, natural evils which damage our faculties depriving them of proper function.


In his Metaphysics (Book Theta, chapter 9) Aristotle makes a comment that suggests he also thinks of bad/evil as a privation. Rather than being some positive substance that exists on its own, it is a deficiency, corruption, of perversion of something else that is a substance. He writes: “Clearly, then, the bad does not exist apart from bad things; for the bad is in its nature posterior to the potency. And therefore we may also say that in the things which are from the beginning, i.e. in eternal things, there is nothing bad, nothing defective, nothing perverted (for perversion is something bad).” This connects nicely to Aristotle’s analysis of virtue in Nicomachean Ethics: vices are insufficiently actualized potentials for virtues that, insofar as they are perversions, dispose us to bad and/or evil actions that thwart the actualization of our rational and social nature. For example, rashness and cowardice are both vices or perversions of the virtue of courage which can lead us to make irrational decisions that adversely affect our relations with others.


In Plotinus’ Enneads (Book One, Tractate 8, Chapter 5) we encounter an extreme view of privation that asserts evil is absolute lack that has no share in the Good or the One which, for Plotinus, is the immaterial, simple, and perfect foundation for everything that has being. Everything except matter participates in the being offered by the One. So Plotinus thinks matter is evil since it has no being: it is that which is not. As such, matter is the principle of evil that can influence people, who are not evil themselves, to act evil. We can avoid such evil actions if we align ourselves with the immaterial Good and the powers that flow from it:

“Evil is not in any and every lack; it is in absolute lack. What falls in some degree short of the Good is not Evil; considered in its own kind it might even be perfect, but where there is utter dearth, there we have Essential Evil, void of all share in Good; this is the case with Matter. Matter has not even existence whereby to have some part in Good: Being is attributed to it by an accident of words: the truth would be that it has Non-Being. Mere lack brings merely Not-Goodness: Evil demands the absolute lack… In fine we are not to think of Evil as some particular bad thing – injustice, for example, or any other ugly trait – but as a principle distinct from any of the particular forms in which, by the addition of certain elements, it becomes manifest….If all this be true, we cannot be, ourselves, the source of Evil, we are not evil in ourselves; Evil was before we came to be; the Evil which holds men down binds them against their will; and for those that have the strength – not found in all men, it is true – there is a deliverance from the evils that have found lodgement in the soul. In a word since Matter belongs only to the sensible world, vice in men is not the Absolute Evil; not all men are vicious; some overcome vice, some, the better sort, are never attacked by it; and those who master it win by means of that in them which is not material.” (translated by Stephen MacKenna and B. S. Page)

The Privation Theory in Augustine and Aquinas

Perhaps the most definitive versions of the privation theory of evil are developed in the middle ages by  St. Augustine and St. Thomas Aquinas. Let’s first look at a passage from the former: 

“For what is that which we call evil but the absence of good? In the bodies of animals, disease and wounds mean nothing but the absence of health; for when a cure is effected, that does not mean that the evils which were present – namely, the diseases and wounds – go away from the body and dwell elsewhere: they altogether cease to exist; for the wound or disease is not a substance, but a defect in the fleshly substance – the flesh itself being a substance, and therefore something good, of which those evils – that is, privations of the good which we call health – are accidents. Just in the same way, what are called vices in the soul are nothing but privations of natural good. And when they are not transferred elsewhere: when they cease to exist in the healthy soul, they cannot exist anywhere else.” See The Essential Augustine (Hackett, 1974), p. 65.

Here we see Augustine arguing that privations have no substance of their own. But, unlike Plotinus who claimed evil is the absence of all good, he is claiming privations must be understood as absences in relation to things that have some degree of goodness. And if privations are evil then we must be talking about the absence of some “natural good” for some particular being. This view is more in line with what is implicitly or explicitly presented in Plato and Aristotle. For example, a stone’s inability to see isn’t evil since a stone, by nature, can’t see. But blindness in a cat would be evil since a properly functioning cat should, by nature, have the good of sight. Turning to humans, we could argue, following Aristotle, that we are by nature rational animals. Thus actualizing our rational potential leads to the fulfillment of proper functioning. This functioning would be naturally good and any act that facilitates it would be right. Once we have this account of our nature in place we can discern various privations as evil insofar as they contribute to undermining reason.  

In his Summa Theologica (First Part, Question 49) St. Thomas Aquinas concurs with this understanding of privation and then offers an account of the cause of it which shows how the privation theory need not exclude positive factors: 

“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.”

Evil doesn’t itself cause anything; rather, it can only come about because some good or non-privative factors are present. For example, a person with a privation of empathy can only do a morally evil act because of certain goods that are present, namely, a properly functioning body, certain cognitive abilities, free will, and so on.

The Privation Theory of Evil

This brief survey shows how subtle thinking about evil as privation has been. In the interest of distilling things down a bit, I think we should accept Peter King’s more specific and defensible formulation of Augustine’s privation theory in Evil: A History (Oxford, 2019): 

  • “More exactly, an evil for x is not having something x naturally needs to be able to flourish (to do well) as an x of kind K.”

He also adds a helpful account of evil tendencies:

  • “Where appropriate, we can say that it is not merely the privation of some requisite natural good that is evil, but whatever tends to such privation. This has two aspects: First, it can refer to the progressive diminution of the requisite feature, much as a disease can progressively sap someone’s strength and will to live. Second, it can refer to habits or dispositions that work against enabling the realization of the relevant natural good, even when it is not actively interfering; a choleric disposition may count as evil because the tendency to anger may interfere with one’s ability to exercise rationality. Including tendencies as evil allows us to treat the factors contributing to privations as themselves evil.” (162-163)

As we have seen the word ‘evil’ in the privation tradition has been used widely and can refer to moral, natural, and even, in some rare cases, metaphysical evil. So let’s summarize these types of evil in accordance with privation before moving on to the next two posts: 

(1) Metaphysical evil privations: these would be the various ways things in the world, simply by virtue of being finite, are deprived of some certain powers to act, know, will, exist, and so on. This form of privation will only make sense if there is a way to speak of these limitations as privations of what, by nature, should be there. Plato’s metaphysics, as we have seen, may offer such an account by claiming that the world is an imperfect imitation of the perfect ideas. Ontological limitation as such is not evil according to the privation theory; only limitations that thwart something’s nature are. However, in most cases we will be accepting that things are imperfect and limited by nature so this form of evil will have limited application when using the privation theory.    

(2) Naturally evil privations: these would be all the ways things are deprived from realizing their natural goods by illness, environmental disaster, genetic mutations, etc. in ways that cause suffering. These privations wouldn’t be connected to free will and moral accountability. So the blindness of a cat would refer to a privation that is naturally evil, that is, one that leads to suffering, failure, and so on for which no one is morally responsible.

(3) Morally evil privations: these would all the ways privations are connected to free choice and responsibility. For example, one can have a privation of courage and be a bit of a coward. Then, based on this privation, one might freely decide to tell a lie in order to avoid a conflict which a courageous person would face. Thus we would have are certain privation of courage that, when aligned with free will, led to immoral action that can introduce further privations in others. Of course, we might be inclined to label this act of lying as bad rather than evil. However, someone with a privation of empathy who freely chose to blind a child for fun would, presumably, commit an evil act. So we might delineate a set of privations under this heading as properly evil rather than bad. This can be done with a careful analysis of the nature of the privations as far as motives, acts, and consequences are concerned. But whatever the case may be, the badness and evil will have to be understood to with reference to what should, by nature, be present. 

In the next post we will look at some objections to the privation theory and responses to them.

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