Objection 1: It would seem that there can be other sins in the angels besides those of pride and envy. Because whosoever can delight in any kind of sin, can fall into the sin itself. But the demons delight even in the obscenities of carnal sins; as Augustine says (De Civ. Dei xiv, 3). Therefore there can also be carnal sins in the demons.
Obj. 2: Further, as pride and envy are spiritual sins, so are sloth, avarice, and anger. But spiritual sins are concerned with the spirit, just as carnal sins are with the flesh. Therefore not only can there be pride and envy in the angels; but likewise sloth and avarice.
Obj. 3: Further, according to Gregory (Moral. xxxi), many vices spring from pride; and in like manner from envy. But, if the cause is granted, the effect follows. If, therefore, there can be pride and envy in the angels, for the same reason there can likewise be other vices in them.
On the contrary, Augustine says (De Civ. Dei xiv, 3) that the devil "is not a fornicator nor a drunkard, nor anything of the like sort; yet he is proud and envious."
I answer that, Sin can exist in a subject in two ways: first of all by actual guilt, and secondly by affection. As to guilt, all sins are in the demons; since by leading men to sin they incur the guilt of all sins. But as to affection only those sins can be in the demons which can belong to a spiritual nature. Now a spiritual nature cannot be affected by such pleasures as appertain to bodies, but only by such as are in keeping with spiritual things; because nothing is affected except with regard to something which is in some way suited to its nature. But there can be no sin when anyone is incited to good of the spiritual order; unless in such affection the rule of the superior be not kept. Such is precisely the sin of pride--not to be subject to a superior when subjection is due. Consequently the first sin of the angel can be none other than pride.
Yet, as a consequence, it was possible for envy also to be in them, since for the appetite to tend to the desire of something involves on its part resistance to anything contrary. Now the envious man repines over the good possessed by another, inasmuch as he deems his neighbor's good to be a hindrance to his own. But another's good could not be deemed a hindrance to the good coveted by the wicked angel, except inasmuch as he coveted a singular excellence, which would cease to be singular because of the excellence of some other. So, after the sin of pride, there followed the evil of envy in the sinning angel, whereby he grieved over man's good, and also over the Divine excellence, according as against the devil's will God makes use of man for the Divine glory.
Reply Obj. 1: The demons do not delight in the obscenities of the sins of the flesh, as if they themselves were disposed to carnal pleasures: it is wholly through envy that they take pleasure in all sorts of human sins, so far as these are hindrances to a man's good.
Reply Obj. 2: Avarice, considered as a special kind of sin, is the immoderate greed of temporal possessions which serve the use of human life, and which can be estimated in value of money; to these demons are not at all inclined, any more than they are to carnal pleasures. Consequently avarice properly so called cannot be in them. But if every immoderate greed of possessing any created good be termed avarice, in this way avarice is contained under the pride which is in the demons. Anger implies passion, and so does concupiscence; consequently they can only exist metaphorically in the demons. Sloth is a kind of sadness, whereby a man becomes sluggish in spiritual exercises because they weary the body; which does not apply to the demons. So it is evident that pride and envy are the only spiritual sins which can be found in demons; yet so that envy is not to be taken for a passion, but for a will resisting the good of another.
Reply Obj. 3: Under envy and pride, as found in the demons, are comprised all other sins derived from them.