• on 19th October 2017

The Problem of Evil in St Thomas Aquinas

Front of church from low angle image
St Thomas Aquinas on the problem of evil
St Thomas Aquinas on the problem of evil

Beginning with a brief look at the Summa Theologiæ; right at the beginning the problem of evil makes an entrance. “Videtur quod Deus non sit…Invenitur autem malum in mundo. Ergo Deus non est.” “It seems that God does not exist…We find evil in the world. Therefore God is not.” (S.T. Ia, 2, 3). Fear not, the Angelic Doctor is not actually arguing for God’s non-existence, indeed this is followed shortly by his famous ‘five ways’ as a rebuttal, but the fact that he states the problem of evil as his first objection to God’s existence suggests that he regards it as a potent and important argument. His response, to my mind, whilst entirely true, is not going to cause many atheists to embrace the faith.

Composed at about the same time as the Summa his text Quaestiones disputatae de malo (‘Disputed Questions Concerning Evil’ or simply de Malo) goes into the subject in more depth – considering this text it is, perhaps, worth keeping in mind that St Thomas regards this as the strongest argument against God’s existence, and therefore there is a real pressing need to produce convincing arguments to deal with it.

At the beginning Leo XIII was quoted, citing Cajetan, he ascribed St Thomas’ greatness not merely to his own merits but to his assimilation within himself of the great work done by the thinkers who preceded him. His position can be seen as in continuity, building on the work of earlier thinkers, and especially pseudo-Denys; and hopefully thereby creating a stronger case than would otherwise be offered.

St Thomas begins with a question “whether evil is something” and responds that it is not, but rather that it is a privation. As is often the case he proceeds by dividing out the nature of that which is under analysis. There are two types of privation: privation of perfection of existence (such as death or blindness) and privation as reduction of perfections (such as illness or ophthalmia) – these two relate to each other, in that the latter privations place a person on the road to the former.

Considering whether evil exists in the good St Thomas makes a critical step which, in my opinion, is central to understanding God’s rôle in evil; by this he solves a significant problem which his predecessors faced. He begins by noting that good and evil are opposites, and thus the latter cannot exist in the former (just as cold cannot exist in hot); however, evil is there in good which is potential – potency is not the opposite of perfection or privation, and thus can be alongside them.

‘The good’ is, surprisingly enough, split into two senses: the absolute good, and particular good (e.g., a good man or a good eye). In the former, evil does not exist; the absolute good has the greatest possible extension (broader even than being) and thus does not admit of scope for privation. The particular good, however, does admit of privation, because it admits of potentiality.

Potential has itself the form of a good; matter is in itself potency (cf. Aristotle’s prime matter which is potency alone) and thus is good. Man, therefore, is good simply by being; it does not follow from this that he is a good man. A good man has a set of perfections proper to him (the virtues); similarly a good eye has a set of perfections proper to it. The fulfilment of these proper perfections is the particular good. They exist first in a man (or an eye, or an anything) in potential, which potential is to be actualised. Now he gives us three ways of speaking of the good: a thing’s perfection (sharp vision), the thing having proper perfections (a sharp eye), and a thing in potency to perfection. Evil is the privation of due perfection, that is the prevention of the potential’s actualisation. Thus evil is in good insofar as potency is called good. When good is seen as the combination of the subject and its perfections, then good is diminished by evil, and thus is not in it. Where good is pure act, and has no potency, then there is no scope for evil – this applies primarily to God.

The separation here into potency and actuality is of vital importance. One of the problems in the thought of pseudo-Denys’ account of evil as a privation was that there is an apparent necessity behind the privation. His neo-Platonic account of being, with privation represented by departure from a central point, can be seen as meaning that God created beings and forced this privation upon them – the difference between this and a position that God created evil is not entirely clear.

St Thomas proceeds to consider whether good is the cause of evil. He states “In the manner in which evil can have a cause, that cause is the good. But evil cannot have an essential cause.” An essential cause needs to be intended, and evil is never intended only accidental – his chosen example being an adulterer who does not choose the evil of adultery because it is evil but rather because there are sensual pleasures involved (or so we are led to believe), the adulterer pursues these pleasures, which are goods. How, then, does evil come about – again the division into potentiality and actuality is critical; it inheres where a proper perfection should be. Importantly it does not do so by nature, because the natural lack of a perfection is not evil (for example a stone’s being unable to see).

Evil still needs an accidental cause, however, and that cause has to be good. Good causes evil in two ways: where good is deficient, and where good is accidental. His example here appears at first to be hopelessly outdated in its physics – fire is not essentially destructive of water, however it does essentially seek to the production of its own form in matter, and this in turn, accidentally necessitates the destruction of water. We need not, I think, embrace the physics of four elements if rather than fire we consider heat as a form of energy – it seeks to propagate itself (higher energy), it does not seek to transform liquids into gases though this is an effect of higher energy levels in them. Having had the good sense to stop studying physics after receiving an A level I am more than willing to be corrected if this doesn’t follow. In the moral sphere, however, I think that the principle of accidental effects is well established – he notes that relative goods are pursued, and these are often conjoined with evil (as in the case of sensual pleasures being conjoined with adultery).

This move into the moral sphere presents us with the action of the will; this is capable of causing evil accidentally (as mentioned a few moments ago), but also of causing evil through a deficiency. The good involves things which are to be ruled being ruled; when the will produces choices without considering appropriate rules it is causing sin through a defect. It seems that these two are not without potential overlap; the adulterer is seeking a relative good conjoined to evil, and is also allowing an inordinate attraction to sensual pleasure to guide him (a deficiency of the will).

There then follows a discussion of dividing evil into sin and punishment. This does not strike me as contributing greatly to the question at hand; however, in brief, St Thomas suggests that sin is an evil of action itself, whereas punishment is an evil of acting. In the natural realm the evil of the agent follows the evil of action (for example limping follows and is caused by a crooked leg); by contrast in voluntary beings the evil of action follows the evil of the agent. This evil of action is sin, and the evil of the agent punishment. Whilst this is mostly tangential to our particular discussion, it is worth noting that there is a constant pattern of instances where a deficiency leads to evil – it is impossible to escape this fundamental insight, that evil is a privation of good.

The final article in our chapter jumps to the third question of de Malo. Here we reach the finish line with the question “does God cause evil” – well sort of, the Latin text states the question as “utrum Deus sit causa peccati”, the translation I was able to use seems to treat ‘sin’ and ‘evil’ as synonymous at a number of points, so caveat lector. There are two ways in which one can sin: by committing a sin, or by making another commit a sin. Considering the former, sin arises in natural things that in acting do not achieve the end for which they act; in moral things they sin where there is a short-fall of will – clearly neither of these can apply to God. However, in the second instance, ‘does God cause others to sin?’ the question is more complex. It is impossible for God to prevent the will of others from its ultimate end because God himself is the ultimate end; God does not attract to evil, however in some instances he does not prevent the attraction to evil.

St Thomas gives the example of a man seeing another who is about to fall, if he fails to put out his hand to steady the man he could be said to be a cause of the man’s falling – is the same true of God? God’s foreknowledge means that he is aware of the many instances in which we are going to fall; should he always steady us? St Thomas contends that his foreknowledge also means that his awareness include knowledge as to those instances in which his aid will prevent, or not prevent, the falling. As God’s action would not have changed the outcome, it cannot be said to have been caused by him. This is, of course, and quite legitimately, based on human free-will; God can prevent a stone from falling without doing violence to the nature of a stone, however, he cannot prevent a man from falling morally without doing violence to the man’s freedom to fall. It is part of the almost inscrutable nature of free-will that although God causes free-will in his creation of us, he is not thereby the cause of the choices which result from it. Sins, in particular, do not arise from the irascible and concupiscible elements within us as created by God; but from our failure to comply with their created natures. St Thomas gives the example of a knee; its movement is caused by the motive power of the animal influencing it, its limitations (for example if the knee is injured) do not come from that motive power but rather from the knee’s failure to receive the power. Thus God causes our actions, but our (self-)injured position prevents us from receiving his power at all times.

This brings us to a position where, I suggest, St Thomas has established that evil does not exist, but rather is a privation of existence. Through the separation of actuality and potentiality it is possible that evil is with us not having been caused by God (despite his being the creator of all that is); however, this does still leave the alternative formulation of the problem of evil which is ‘why does a benevolent God allow it?’ This is different to asking how he could have created it. One might ask why God in creating allowed for this potentiality into which evil could, as it were, sneak. An answer, which St Thomas gives, can be found in the Summa article I mentioned at the beginning – he cites St Augustine, and agrees with him that God’s benevolence meets with his omnipotence, and that he could only allow evil because he can bring further good out of it. “This is part of the infinite goodness of God that he should allow evil to exist, and out of it produce good.” This strikes me as entirely true; however, it also strikes me as working backwards from God’s existence – the argument presupposes God, thus in an apologetic debate I doubt that it would convince many waverers. Perhaps what this illustrates is that in the realm of philosophy we can answer the problem of evil only in terms of showing that it is not incompatible with God; but this will leave us scratching our heads wondering why he would even allow it, until we allow a more Theological account to answer.

There is also something of a lacuna in the lack of a consideration of natural suffering; it is fairly clear that free will can be the cause of moral evil, but the step from my sinning through making bad choices to innocent children dying from diseases or earthquakes is still not entirely covered. The answer given in the Summa does have the potential to cover this as well – allowing for a greater good to emerge, but that’s at the level of divine permission, I think, and does not explain the cause.

What I think is clear is that St Thomas has contributed significantly to an understanding of how we may find evil’s constant present not to challenge our belief in God. However, a question with such great power (as the Angelic Doctor implicitly acknowledges) is not subject to tidy, simple, and final answers. Thus, the question is not finally answered by St Thomas and is in need of constant meditation and consideration if the Church is to offer a credible apologetic to an increasingly sceptical world.