Summa Theologica, by St. Thomas Aquinas, [1947], at sacred-texts.com
We must now consider the cause of virtues; and under this head there are four points of inquiry:
(1) Whether virtue is in us by nature?
(2) Whether any virtue is caused in us by habituation?
(3) Whether any moral virtues are in us by infusion?
(4) Whether virtue acquired by habituation, is of the same species as infused virtue?
Objection 1: It would seem that virtue is in us by nature. For Damascene says (De Fide Orth. iii, 14): "Virtues are natural to us and are equally in all of us." And Antony says in his sermon to the monks: "If the will contradicts nature it is perverse, if it follow nature it is virtuous." Moreover, a gloss on Mat. 4:23, "Jesus went about," etc., says: "He taught them natural virtues, i.e. chastity, justice, humility, which man possesses naturally."
Objection 2: Further, the virtuous good consists in accord with reason, as was clearly shown above (Q[55], A[4], ad 2). But that which accords with reason is natural to man; since reason is part of man's nature. Therefore virtue is in man by nature.
Objection 3: Further, that which is in us from birth is said to be natural to us. Now virtues are in some from birth: for it is written (Job 31:18): "From my infancy mercy grew up with me; and it came out with me from my mother's womb." Therefore virtue is in man by nature.
On the contrary, Whatever is in man by nature is common to all men, and is not taken away by sin, since even in the demons natural gifts remain, as Dionysius states (Div. Nom. iv). But virtue is not in all men; and is cast out by sin. Therefore it is not in man by nature.
I answer that, With regard to corporeal forms, it has been maintained by some that they are wholly from within, by those, for instance, who upheld the theory of "latent forms" [*Anaxagoras; Cf. FP, Q[45], A[8]; Q[65], A[4]]. Others held that forms are entirely from without, those, for instance, who thought that corporeal forms originated from some separate cause. Others, however, esteemed that they are partly from within, in so far as they pre-exist potentially in matter; and partly from without, in so far as they are brought into act by the agent.
In like manner with regard to sciences and virtues, some held that they are wholly from within, so that all virtues and sciences would pre-exist in the soul naturally, but that the hindrances to science and virtue, which are due to the soul being weighed down by the body, are removed by study and practice, even as iron is made bright by being polished. This was the opinion of the Platonists. Others said that they are wholly from without, being due to the inflow of the active intellect, as Avicenna maintained. Others said that sciences and virtues are within us by nature, so far as we are adapted to them, but not in their perfection: this is the teaching of the Philosopher (Ethic. ii, 1), and is nearer the truth.
To make this clear, it must be observed that there are two ways in which something is said to be natural to a man; one is according to his specific nature, the other according to his individual nature. And, since each thing derives its species from its form, and its individuation from matter, and, again, since man's form is his rational soul, while his matter is his body, whatever belongs to him in respect of his rational soul, is natural to him in respect of his specific nature; while whatever belongs to him in respect of the particular temperament of his body, is natural to him in respect of his individual nature. For whatever is natural to man in respect of his body, considered as part of his species, is to be referred, in a way, to the soul, in so far as this particular body is adapted to this particular soul.
In both these ways virtue is natural to man inchoatively. This is so in respect of the specific nature, in so far as in man's reason are to be found instilled by nature certain naturally known principles of both knowledge and action, which are the nurseries of intellectual and moral virtues, and in so far as there is in the will a natural appetite for good in accordance with reason. Again, this is so in respect of the individual nature, in so far as by reason of a disposition in the body, some are disposed either well or ill to certain virtues: because, to wit, certain sensitive powers are acts of certain parts of the body, according to the disposition of which these powers are helped or hindered in the exercise of their acts, and, in consequence, the rational powers also, which the aforesaid sensitive powers assist. In this way one man has a natural aptitude for science, another for fortitude, another for temperance: and in these ways, both intellectual and moral virtues are in us by way of a natural aptitude, inchoatively, but not perfectly, since nature is determined to one, while the perfection of these virtues does not depend on one particular mode of action, but on various modes, in respect of the various matters, which constitute the sphere of virtue's action, and according to various circumstances.
It is therefore evident that all virtues are in us by nature, according to aptitude and inchoation, but not according to perfection, except the theological virtues, which are entirely from without.
This suffices for the Replies to the Objections. For the first two argue about the nurseries of virtue which are in us by nature, inasmuch as we are rational beings. The third objection must be taken in the sense that, owing to the natural disposition which the body has from birth, one has an aptitude for pity, another for living temperately, another for some other virtue.
Objection 1: It would seem that virtues can not be caused in us by habituation. Because a gloss of Augustine [*Cf. Lib. Sentent. Prosperi cvi.] commenting on Rom. 14:23, "All that is not of faith is sin," says: "The whole life of an unbeliever is a sin: and there is no good without the Sovereign Good. Where knowledge of the truth is lacking, virtue is a mockery even in the best behaved people." Now faith cannot be acquired by means of works, but is caused in us by God, according to Eph. 2:8: "By grace you are saved through faith." Therefore no acquired virtue can be in us by habituation.
Objection 2: Further, sin and virtue are contraries, so that they are incompatible. Now man cannot avoid sin except by the grace of God, according to Wis. 8:21: "I knew that I could not otherwise be continent, except God gave it." Therefore neither can any virtues be caused in us by habituation, but only by the gift of God.
Objection 3: Further, actions which lead toward virtue, lack the perfection of virtue. But an effect cannot be more perfect than its cause. Therefore a virtue cannot be caused by actions that precede it.
On the contrary, Dionysius says (Div. Nom. iv) that good is more efficacious than evil. But vicious habits are caused by evil acts. Much more, therefore, can virtuous habits be caused by good acts.
I answer that, We have spoken above (Q[51], AA[2],3) in a general way about the production of habits from acts; and speaking now in a special way of this matter in relation to virtue, we must take note that, as stated above (Q[55], AA[3],4), man's virtue perfects him in relation to good. Now since the notion of good consists in "mode, species, and order," as Augustine states (De Nat. Boni. iii) or in "number, weight, and measure," as expressed in Wis. 11:21, man's good must needs be appraised with respect to some rule. Now this rule is twofold, as stated above (Q[19], AA[3],4), viz. human reason and Divine Law. And since Divine Law is the higher rule, it extends to more things, so that whatever is ruled by human reason, is ruled by the Divine Law too; but the converse does not hold.
It follows that human virtue directed to the good which is defined according to the rule of human reason can be caused by human acts: inasmuch as such acts proceed from reason, by whose power and rule the aforesaid good is established. On the other hand, virtue which directs man to good as defined by the Divine Law, and not by human reason, cannot be caused by human acts, the principle of which is reason, but is produced in us by the Divine operation alone. Hence Augustine in giving the definition of the latter virtue inserts the words, "which God works in us without us" (Super Ps. 118, Serm. xxvi). It is also of these virtues that the First Objection holds good.
Reply to Objection 2: Mortal sin is incompatible with divinely infused virtue, especially if this be considered in its perfect state. But actual sin, even mortal, is compatible with humanly acquired virtue; because the use of a habit in us is subject to our will, as stated above (Q[49], A[3]): and one sinful act does not destroy a habit of acquired virtue, since it is not an act but a habit, that is directly contrary to a habit. Wherefore, though man cannot avoid mortal sin without grace, so as never to sin mortally, yet he is not hindered from acquiring a habit of virtue, whereby he may abstain from evil in the majority of cases, and chiefly in matters most opposed to reason. There are also certain mortal sins which man can nowise avoid without grace, those, namely, which are directly opposed to the theological virtues, which are in us through the gift of grace. This, however, will be more fully explained later (Q[109], A[4]).
Reply to Objection 3: As stated above (A[1]; Q[51], A[1]), certain seeds or principles of acquired virtue pre-exist in us by nature. These principles are more excellent than the virtues acquired through them: thus the understanding of speculative principles is more excellent than the science of conclusions, and the natural rectitude of the reason is more excellent than the rectification of the appetite which results through the appetite partaking of reason, which rectification belongs to moral virtue. Accordingly human acts, in so far as they proceed from higher principles, can cause acquired human virtues.
Objection 1: It would seem that no virtues besides the theological virtues are infused in us by God. Because God does not do by Himself, save perhaps sometimes miraculously, those things that can be done by second causes; for, as Dionysius says (Coel. Hier. iv), "it is God's rule to bring about extremes through the mean." Now intellectual and moral virtues can be caused in us by our acts, as stated above (A[2]). Therefore it is not reasonable that they should be caused in us by infusion.
Objection 2: Further, much less superfluity is found in God's works than in the works of nature. Now the theological virtues suffice to direct us to supernatural good. Therefore there are no other supernatural virtues needing to be caused in us by God.
Objection 3: Further, nature does not employ two means where one suffices: much less does God. But God sowed the seeds of virtue in our souls, according to a gloss on Heb. 1 [*Cf. Jerome onGal. 1:15, 16]. Therefore it is unfitting for Him to cause in us other virtues by means of infusion.
On the contrary, It is written (Wis. 8:7): "She teacheth temperance and prudence and justice and fortitude."
I answer that, Effects must needs be proportionate to their causes and principles. Now all virtues, intellectual and moral, that are acquired by our actions, arise from certain natural principles pre-existing in us, as above stated (A[1]; Q[51], A[1]): instead of which natural principles, God bestows on us the theological virtues, whereby we are directed to a supernatural end, as stated (Q[62], A[1]). Wherefore we need to receive from God other habits corresponding, in due proportion, to the theological virtues, which habits are to the theological virtues, what the moral and intellectual virtues are to the natural principles of virtue.
Reply to Objection 1: Some moral and intellectual virtues can indeed be caused in us by our actions: but such are not proportionate to the theological virtues. Therefore it was necessary for us to receive, from God immediately, others that are proportionate to these virtues.
Reply to Objection 2: The theological virtues direct us sufficiently to our supernatural end, inchoatively: i.e. to God Himself immediately. But the soul needs further to be perfected by infused virtues in regard to other things, yet in relation to God.
Reply to Objection 3: The power of those naturally instilled principles does not extend beyond the capacity of nature. Consequently man needs in addition to be perfected by other principles in relation to his supernatural end.
Objection 1: It would seem that infused virtue does not differ in species from acquired virtue. Because acquired and infused virtues, according to what has been said (A[3]), do not differ seemingly, save in relation to the last end. Now human habits and acts are specified, not by their last, but by their proximate end. Therefore the infused moral or intellectual virtue does not differ from the acquired virtue.
Objection 2: Further, habits are known by their acts. But the act of infused and acquired temperance is the same, viz. to moderate desires of touch. Therefore they do not differ in species.
Objection 3: Further, acquired and infused virtue differ as that which is wrought by God immediately, from that which is wrought by a creature. But the man whom God made, is of the same species as a man begotten naturally; and the eye which He gave to the man born blind, as one produced by the power of generation. Therefore it seems that acquired and infused virtue belong to the same species.
On the contrary, Any change introduced into the difference expressed in a definition involves a difference of species. But the definition of infused virtue contains the words, "which God works in us without us," as stated above (Q[55], A[4]). Therefore acquired virtue, to which these words cannot apply, is not of the same species as infused virtue.
I answer that, There is a twofold specific difference among habits. The first, as stated above (Q[54], A[2]; Q[56], A[2]; Q[60], A[1]), is taken from the specific and formal aspects of their objects. Now the object of every virtue is a good considered as in that virtue's proper matter: thus the object of temperance is a good in respect of the pleasures connected with the concupiscence of touch. The formal aspect of this object is from reason which fixes the mean in these concupiscences: while the material element is something on the part of the concupiscences. Now it is evident that the mean that is appointed in such like concupiscences according to the rule of human reason, is seen under a different aspect from the mean which is fixed according to Divine rule. For instance, in the consumption of food, the mean fixed by human reason, is that food should not harm the health of the body, nor hinder the use of reason: whereas, according to the Divine rule, it behooves man to "chastise his body, and bring it into subjection" (1 Cor. 9:27), by abstinence in food, drink and the like. It is therefore evident that infused and acquired temperance differ in species; and the same applies to the other virtues.
The other specific differences among habits is taken from the things to which they are directed: for a man's health and a horse's are not of the same species, on account of the difference between the natures to which their respective healths are directed. In the same sense, the Philosopher says (Polit. iii, 3) that citizens have diverse virtues according as they are well directed to diverse forms of government. In the same way, too, those infused moral virtues, whereby men behave well in respect of their being "fellow-citizens with the saints, and of the household [Douay: 'domestics'] of God" (Eph. 2:19), differ from the acquired virtues, whereby man behaves well in respect of human affairs.
Reply to Objection 1: Infused and acquired virtue differ not only in relation to the ultimate end, but also in relation to their proper objects, as stated.
Reply to Objection 2: Both acquired and infused temperance moderate desires for pleasures of touch, but for different reasons, as stated: wherefore their respective acts are not identical.
Reply to Objection 3: God gave the man born blind an eye for the same act as the act for which other eyes are formed naturally: consequently it was of the same species. It would be the same if God wished to give a man miraculously virtues, such as those that are acquired by acts. But the case is not so in the question before us, as stated.