Summa contra Gentiles3.109 Chapter CIX. That sin is possible in the demons, and how

That sin of the will is in the demons is clear from the authority of Scripture. For it is said (1 Jo. iii. 8) that the devil sinneth from the beginning; and (Jo. viii. 44) it is said that the devil is a liar, and the father of lies, and that he was a murderer from the beginning: and (Wis. ii. 24) that by the envy of the devil, death came into the world.

If anyone chose to follow the opinions of the Platonists, he would easily explain these authorities. For they assert that demons have a body composed of air: and so, since they have a body united to them, there can be a faculty of sense in them. Hence they ascribe to them passions which in us are a cause of sin, namely anger, hate and the like, wherefore Apuleius says that they are passive in mind.

Moreover, independently of their being united to bodies, as the Platonists aver, perhaps yet another kind of knowledge might be assigned to them besides that of the intellect. For, according to Plato, the sensitive soul also is incorruptible: so that it must have an operation in which the body does not concur. Consequently, nothing prevents the operation of the sensitive soul, and therefore the passions, from being in an intellectual substance, even though it be not united to a body. Hence the same source of sin is seated in them as in us.

But both of these explanations are impossible. For it has been proved above that with the exception of human souls no other intellectual substances are united to bodies.—And that the operations of the sensitive soul are impossible apart from a body, is clear from the fact, that when a sensorial organ is destroyed, the one operation of the sense is destroyed: thus sight ceases with the loss of an eye. For this reason as soon as the organ of touch is destroyed, the animal must die, for it cannot live without it.

In order to solve the question proposed, then, we must observe that, just as there is order among active causes, so too is there in final causes: so that, to wit, the secondary end depends on the principal end, even as the secondary agent depends on the principal agent. Now, a fault occurs in active causes when the secondary agent strays from the order of the principal agent; just as, when the tibia fails to accomplish the movement commanded by the appetitive power through being crooked, the result is a limping gait. In the same way, therefore, in final causes also, when the secondary end is not subordinate to the principal end, there is sin in the will, the obj ect of which is the good and the end.

Now every will naturally desires that which is the proper good of the wilier, namely perfect being, nor can it will anything contrary to this. Accordingly, no sin of the will can occur in a wilier whose proper good is the ultimate end, which is not subordinate to any other end, and to which all other ends are subordinate. Such a wilier is God, whose being is the sovereign good, which is the ultimate end. Therefore in God there can be no sin of the will.

But in every other wilier, whose proper good must needs be subordinate to another good, sin of the will can occur, if we consider him in his nature. For, though the natural inclination of the will in every wilier be to will and love his own perfection, so that it cannot will anything contrary thereto; yet it is not naturally implanted in him so that he directs his perfection to another end unfailingly: since the higher end is not his proper end, but that of the superior nature. Wherefore it is left to his discretion to direct his own perfection to a higher end. For beings endowed with a will differ from those which are not so endowed, in that the former direct themselves and what is theirs to an end, wherefore they are said to have free-will: whereas the latter do not direct themselves to an end, but are directed by a higher agent, being, as it were, moved to the end by another’s action, and not by their own.

Hence there could be sin in the will of a separate substance, through his not directing his own good and perfection to his last end, and adhering to his own good as his end. And since rules of action must needs be taken from the end, the consequence was that, through making himself his own end, he pretended to submit other things to his rule, and that his will was not subject to another higher than himself. But this belongs to God alone. In this sense then we are to understand that he desired to be equal to God: not that his good might be equal to the divine good; because such a thing could not come into his mind; and because by desiring it he would desire not to be, since the distinction of species is according to the various degrees of things, as is clear from what has been said above.2—Now, the will to rule others, and the refusal to submit one’s will to the ruling of a superior, is the will to be supreme and, so to say, not to be subject, which is the sin of pride. Hence it is reasonably said that the demon’s first sin was pride.—But as from one error about 1 Isa. xiv. ia. 2 Ch. xcvii.; Bk. II., ch. xcv.

a principle, errors various and manifold result, so from the first disorder in the demon’s will, there arose all manner of sins in his will: both of hate towards God as resisting his pride, and most justly punishing his fault; and of envy towards man; and of many such sins.

We must also observe that, as the proper good of a thing is subordinate to several higher goods, the wilier is free to depart from the order of one superior, and not from the order of another that is either higher or lower than the former: thus a soldier who is subordinate both to his king and to his general, can direct his will to the good of the general, and not that of the king, or vice versa. But if the general depart from the order of the king, the will of the soldier will be good, if he depart from the will of his general, and direct his own will, to his king; and the will of the soldier who obeys the will of his general against the will of his king will be evil: because the order of the lower principle depends on the order of the higher. Now, separate substances are not only subordinate to God, but one of them is subordinate to another, from the first to the last, as we proved in the Second Book. And since in every wilier under God there can be sin of the will, if he be considered in his nature, it was possible for one of the higher separate substances, or even the highest of all, to sin in his will. And this indeed is not improbable; for he would not have rested in his good as his end unless that good were very perfect. Possibly then, some of the lower separate substances, of their own will, directed their good to him, thus departing from the divine order, and so sinned even as he did: while others adhering, by the movement of their will, to the divine order, rightly departed from the order of the one who sinned, although he was higher than they in the natural order. In the Fourth Book we shall show how in either case that will of theirs continues unchangeable: for this regards the punishments or rewards of the good or wicked.

There is, however, this difference between a man and a separated substance that in any one man there are several 1 Ch. xcv. 2 Ch. xcii. seqq.

appetitive powers which are subordinated one to the other. But this is not the case with separate substances, although one substance is subordinated to another. Now sin occurs in the will whenever the inferior appetite is turned aside. Just as sin, therefore, would be brought about in a separate substance either by its being turned aside from the divine order or because an inferior substance is turned aside from its order to a superior one, which latter remains under the divine order, so in a man sin occurs in two ways. It occurs in one way from the fact that the human will does not direct its proper good to God; and this sin is common both to man and to separate substances. It occurs in another way from the fact that the lower appetite is not regulated with regard to the higher, as for instance when we will the delights of the flesh, towards which the concupiscible appetite tends, not in accordance with reason. But this kind of sin is not found in separate substances.