Summa Th. I-II EN Qu.71 a.3
1423
Objection: 1. It would seem that vice, i.e. a bad habit, is worse than a sin, i.e. a bad act. For, as the more lasting a good is, the better it is, so the longer an evil lasts, the worse it is. Now a vicious habit is more lasting than vicious acts, that pass forthwith. Therefore a vicious habit is worse than a vicious act.
2. Further, several evils are more to be shunned than one. But a bad habit is virtually the cause of many bad acts. Therefore a vicious habit is worse than a vicious act.
3. Further, a cause is more potent than its effect. But a habit produces its actions both as to their goodness and as to their badness. Therefore a habit is more potent than its act, both in goodness and in badness.
On the contrary A man is justly punished for a vicious act; but not for a vicious habit, so long as no act ensues. Therefore a vicious action is worse than a vicious habit.
I answer that A habit stands midway between power and act. Now it is evident that both in good and in evil, act precedes power, as stated in Metaph. ix, 19. For it is better to do well than to be able to do well, and in like manner, it is more blameworthy to do evil, than to be able to do evil: whence it also follows that both in goodness and in badness, habit stands midway between power and act, so that, to wit, even as a good or evil habit stands above the corresponding power in goodness or in badness, so does it stand below the corresponding act. This is also made clear from the fact that a habit is not called good or bad, save in so far as it induces to a good or bad act: wherefore a habit is called good or bad by reason of the goodness or badness of its act: so that an act surpasses its habit in goodness or badness, since "the cause of a thing being such, is yet more so."
Reply to Objection: 1. Nothing hinders one thing from standing above another simply, and below it in some respect. Now a thing is deemed above another simply if it surpasses it in a point which is proper to both; while it is deemed above it in a certain respect, if it surpasses it in something which is accidental to both. Now it has been shown from the very nature of act and habit, that act surpasses habit both in goodness and in badness. Whereas the fact that habit is more lasting than act, is accidental to them, and is due to the fact that they are both found in a nature such that it cannot always be in action, and whose action consists in a transient movement. Consequently act simply excels in goodness and badness, but habit excels in a certain respect.
2. A habit is several acts, not simply, but in a certain respect, i.e. virtually. Wherefore this does not prove that habit precedes act simply, both in goodness and in badness.
3. Habit causes act by way of efficient causality: but act causes habit, by way of final causality, in respect of which we consider the nature of good and evil. Consequently act surpasses habit both in goodness and in badness.
1424
Objection: 1. It would seem that a vicious act, i.e. sin, is incompatible with virtue. For contraries cannot be together in the same subject. Now sin is, in some way, contrary to virtue, as stated above (Article [1]). Therefore sin is incompatible with virtue.
2. Further, sin is worse than vice, i.e. evil act than evil habit. But vice cannot be in the same subject with virtue: neither, therefore, can sin.
3. Further, sin occurs in natural things, even as in voluntary matters (Phys. ii, text. 82). Now sin never happens in natural things, except through some corruption of the natural power; thus monsters are due to corruption of some elemental force in the seed, as stated in Phys. ii. Therefore no sin occurs in voluntary matters, except through the corruption of some virtue in the soul: so that sin and virtue cannot be together in the same subject.
On the contrary The Philosopher says (Ethic. ii, 2,3) that "virtue is engendered and corrupted by contrary causes." Now one virtuous act does not cause a virtue, as stated above (Question [51], Article [3]): and, consequently, one sinful act does not corrupt virtue. Therefore they can be together in the same subject.
I answer that Sin is compared to virtue, as evil act to good habit. Now the position of a habit in the soul is not the same as that of a form in a natural thing. For the form of a natural thing produces, of necessity, an operation befitting itself; wherefore a natural form is incompatible with the act of a contrary form: thus heat is incompatible with the act of cooling, and lightness with downward movement (except perhaps violence be used by some extrinsic mover): whereas the habit that resides in the soul, does not, of necessity, produce its operation, but is used by man when he wills. Consequently man, while possessing a habit, may either fail to use the habit, or produce a contrary act; and so a man having a virtue may produce an act of sin. And this sinful act, so long as there is but one, cannot corrupt virtue, if we compare the act to the virtue itself as a habit: since, just as habit is not engendered by one act, so neither is it destroyed by one act as stated above (Question [63], Article [2], ad 2). But if we compare the sinful act to the cause of the virtues, then it is possible for some virtues to be destroyed by one sinful act. For every mortal sin is contrary to charity, which is the root of all the infused virtues, as virtues; and consequently, charity being banished by one act of mortal sin, it follows that all the infused virtues are expelled "as virtues." And I say on account of faith and hope, whose habits remain unquickened after mortal sin, so that they are no longer virtues. On the other hand, since venial sin is neither contrary to charity, nor banishes it, as a consequence, neither does it expel the other virtues. As to the acquired virtues, they are not destroyed by one act of any kind of sin.Accordingly, mortal sin is incompatible with the infused virtues, but is consistent with acquired virtue: while venial sin is compatible with virtues, whether infused or acquired.
Reply to Objection: 1. Sin is contrary to virtue, not by reason of itself, but by reason of its act. Hence sin is incompatible with the act, but not with the habit, of virtue.
2. Vice is directly contrary to virtue, even as sin to virtuous act: and so vice excludes virtue, just as sin excludes acts of virtue.
3. The natural powers act of necessity, and hence so long as the power is unimpaired, no sin can be found in the act. On the other hand, the virtues of the soul do not produce their acts of necessity; hence the comparison fails.
1425
Objection: 1. It would seem that every sin includes an action. For as merit is compared with virtue, even so is sin compared with vice. Now there can be no merit without an action. Neither, therefore, can there be sin without action.
2. Further, Augustine says (De Lib. Arb. iii, 18) [*Cf. De Vera Relig. xiv.]: So "true is it that every sin is voluntary, that, unless it be voluntary, it is no sin at all." Now nothing can be voluntary, save through an act of the will. Therefore every sin implies an act.
3. Further, if sin could be without act, it would follow that a man sins as soon as he ceases doing what he ought. Now he who never does something that he ought to do, ceases continually doing what he ought. Therefore it would follow that he sins continually; and this is untrue. Therefore there is no sin without an act.
On the contrary It is written (Jc 4,17): "To him . . . who knoweth to do good, and doth it not, to him it is a sin." Now "not to do" does not imply an act. Therefore sin can be without act.
I answer that The reason for urging this question has reference to the sin of omission, about which there have been various opinions. For some say that in every sin of omission there is some act, either interior or exterior---interior, as when a man wills "not to go to church," when he is bound to go---exterior, as when a man, at the very hour that he is bound to go to church (or even before), occupies himself in such a way that he is hindered from going. This seems, in a way, to amount to the same as the first, for whoever wills one thing that is incompatible with this other, wills, consequently, to go without this other: unless, perchance, it does not occur to him, that what he wishes to do, will hinder him from that which he is bound to do, in which case he might be deemed guilty of negligence. On the other hand, others say, that a sin of omission does not necessarily suppose an act: for the mere fact of not doing what one is bound to do is a sin.Now each of these opinions has some truth in it. For if in the sin of omission we look merely at that in which the essence of the sin consists, the sin of omission will be sometimes with an interior act, as when a man wills "not to go to church": while sometimes it will be without any act at all, whether interior or exterior, as when a man, at the time that he is bound to go to church, does not think of going or not going to church.If, however, in the sin of omission, we consider also the causes, or occasions of the omission, then the sin of omission must of necessity include some act. For there is no sin of omission, unless we omit what we can do or not do: and that we turn aside so as not to do what we can do or not do, must needs be due to some cause or occasion, either united with the omission or preceding it. Now if this cause be not in man's power, the omission will not be sinful, as when anyone omits going to church on account of sickness: but if the cause or occasion be subject to the will, the omission is sinful; and such cause, in so far as it is voluntary, must needs always include some act, at least the interior act of the will: which act sometimes bears directly on the omission, as when a man wills "not to go to church," because it is too much trouble; and in this case this act, of its very nature, belongs to the omission, because the volition of any sin whatever, pertains, of itself, to that sin, since voluntariness is essential to sin. Sometimes, however, the act of the will bears directly on something else which hinders man from doing what he ought, whether this something else be united with the omission, as when a man wills to play at the time he ought to go to church---or, precede the omission, as when a man wills to sit up late at night, the result being that he does not go to church in the morning. In this case the act, interior or exterior, is accidental to the omission, since the omission follows outside the intention, and that which is outside the intention is said to be accidental (Phys. ii, text. 49,50). Wherefore it is evident that then the sin of omission has indeed an act united with, or preceding the omission, but that this act is accidental to the sin of omission.Now in judging about things, we must be guided by that which is proper to them, and not by that which is accidental: and consequently it is truer to say that a sin can be without any act; else the circumstantial acts and occasions would be essential to other actual sins.
Reply to Objection: 1. More things are required for good than for evil, since "good results from a whole and entire cause, whereas evil results from each single defect," as Dionysius states (Div. Nom. iv): so that sin may arise from a man doing what he ought not, or by his not doing what he ought; while there can be no merit, unless a man do willingly what he ought to do: wherefore there can be no merit without act, whereas there can be sin without act.
2. The term "voluntary" is applied not only to that on which the act of the will is brought to bear, but also to that which we have the power to do or not to do, as stated in Ethic. iii, 5. Hence even not to will may be called voluntary, in so far as man has it in his power to will, and not to will.
3. The sin of omission is contrary to an affirmative precept which binds always, but not for always. Hence, by omitting to act, a man sins only for the time at which the affirmative precept binds him to act.
1426
Objection: 1. It would seem that sin is unfittingly defined by saying: "Sin is a word, deed, or desire, contrary to the eternal law." Because "Word," "deed," and "desire" imply an act; whereas not every sin implies an act, as stated above (Article [5]). Therefore this definition does not include every sin.
2. Further, Augustine says (De Duab. Anim. xii): "Sin is the will to retain or obtain what justice forbids." Now will is comprised under desire, in so far as desire denotes any act of the appetite. Therefore it was enough to say: "Sin is a desire contrary to the eternal law," nor was there need to add "word" or "deed."
3. Further, sin apparently consists properly in aversion from the end: because good and evil are measured chiefly with regard to the end as explained above (Question [1], Article [3]; Question [18], Articles [4],6; Question [20], Articles [2],3): wherefore Augustine (De Lib. Arb. i) defines sin in reference to the end, by saying that "sin is nothing else than to neglect eternal things, and seek after temporal things": and again he says (Qq. lxxxii, qu. 30) that "all human wickedness consists in using what we should enjoy, and in enjoying what we should use." Now the definition is question contains no mention of aversion from our due end: therefore it is an insufficient definition of sin.
4. Further, a thing is said to be forbidden, because it is contrary to the law. Now not all sins are evil through being forbidden, but some are forbidden because they are evil. Therefore sin in general should not be defined as being against the law of God.
5. Further, a sin denotes a bad human act, as was explained above (Article [1]). Now man's evil is to be against reason, as Dionysius states (Div. Nom. iv). Therefore it would have been better to say that sin is against reason than to say that it is contrary to the eternal law.
On the contrary the authority of Augustine suffices (Contra Faust. xxii, 27).
I answer that As was shown above (Article [1]), sin is nothing else than a bad human act. Now that an act is a human act is due to its being voluntary, as stated above (Question [1], Article [1]), whether it be voluntary, as being elicited by the will, e.g. to will or to choose, or as being commanded by the will, e.g. the exterior actions of speech or operation. Again, a human act is evil through lacking conformity with its due measure: and conformity of measure in a thing depends on a rule, from which if that thing depart, it is incommensurate. Now there are two rules of the human will: one is proximate and homogeneous, viz. the human reason; the other is the first rule, viz. the eternal law, which is God's reason, so to speak. Accordingly Augustine (Contra Faust. xxii, 27) includes two things in the definition of sin; one, pertaining to the substance of a human act, and which is the matter, so to speak, of sin, when he says "word," "deed," or "desire"; the other, pertaining to the nature of evil, and which is the form, as it were, of sin, when he says, "contrary to the eternal law."
Reply to Objection: 1. Affirmation and negation are reduced to one same genus: e.g. in Divine things, begotten and unbegotten are reduced to the genus "relation," as Augustine states (De Trin. v, 6,7): and so "word" and "deed" denote equally what is said and what is not said, what is done and what is not done.
2. The first cause of sin is in the will, which commands all voluntary acts, in which alone is sin to be found: and hence it is that Augustine sometimes defines sin in reference to the will alone. But since external acts also pertain to the substance of sin, through being evil of themselves, as stated, it was necessary in defining sin to include something referring to external action.
3. The eternal law first and foremost directs man to his end, and in consequence, makes man to be well disposed in regard to things which are directed to the end: hence when he says, "contrary to the eternal law," he includes aversion from the end and all other forms of inordinateness.
4. When it is said that not every sin is evil through being forbidden, this must be understood of prohibition by positive law. If, however, the prohibition be referred to the natural law, which is contained primarily in the eternal law, but secondarily in the natural code of the human reason, then every sin is evil through being prohibited: since it is contrary to natural law, precisely because it is inordinate.
5. The theologian considers sin chiefly as an offense against God; and the moral philosopher, as something contrary to reason. Hence Augustine defines sin with reference to its being "contrary to the eternal law," more fittingly than with reference to its being contrary to reason; the more so, as the eternal law directs us in many things that surpass human reason, e.g. in matters of faith.
1440
We must now consider the distinction of sins or vices: under which head there are nine points of inquiry:
(1) Whether sins are distinguished specifically by their objects?
(2) Of the distinction between spiritual and carnal sins;
(3) Whether sins differ in reference to their causes?
(4) Whether they differ with respect to those who are sinned against?
(5) Whether sins differ in relation to the debt of punishment?
(6) Whether they differ in regard to omission and commission?
(7) Whether they differ according to their various stages?
(8) Whether they differ in respect of excess and deficiency?
(9) Whether they differ according to their various circumstances?
1441
Objection: 1. It would seem that sins do not differ in species, according to their objects. For acts are said to be good or evil, in relation, chiefly, to their end, as shown above (Question [1], Article [3]; Question [18], Articles [4],6). Since then sin is nothing else than a bad human act, as stated above (Question [71], Article [1]), it seems that sins should differ specifically according to their ends rather than according to their objects.
2. Further, evil, being a privation, differs specifically according to the different species of opposites. Now sin is an evil in the genus of human acts. Therefore sins differ specifically according to their opposites rather than according to their objects.
3. Further, if sins differed specifically according to their objects, it would be impossible to find the same specific sin with diverse objects: and yet such sins are to be found. For pride is about things spiritual and material as Gregory says (Moral. xxxiv, 18); and avarice is about different kinds of things. Therefore sins do not differ in species according to their objects.
On the contrary "Sin is a word, deed, or desire against God's law." Now words, deeds, and desires differ in species according to their various objects: since acts differ by their objects, as stated above (Question [18], Article [2]). Therefore sins, also differ in species according to their objects.
I answer that As stated above (Question [71], Article [6]), two things concur in the nature of sin, viz. the voluntary act, and its inordinateness, which consists in departing from God's law. Of these two, one is referred essentially to the sinner, who intends such and such an act in such and such matter; while the other, viz. the inordinateness of the act, is referred accidentally to the intention of the sinner, for "no one acts intending evil," as Dionysius declares (Div. Nom. iv). Now it is evident that a thing derives its species from that which is essential and not from that which is accidental: because what is accidental is outside the specific nature. Consequently sins differ specifically on the part of the voluntary acts rather than of the inordinateness inherent to sin. Now voluntary acts differ in species according to their objects, as was proved above (Question [18], Article [2]). Therefore it follows that sins are properly distinguished in species by their objects.
Reply to Objection: 1. The aspect of good is found chiefly in the end: and therefore the end stands in the relation of object to the act of the will which is at the root of every sin. Consequently it amounts to the same whether sins differ by their objects or by their ends.
2. Sin is not a pure privation but an act deprived of its due order: hence sins differ specifically according to their objects of their acts rather than according to their opposites, although, even if they were distinguished in reference to their opposite virtues, it would come to the same: since virtues differ specifically according to their objects, as stated above (Question [60], Article [5]).
3. In various things, differing in species or genus, nothing hinders our finding one formal aspect of the object, from which aspect sin receives its species. It is thus that pride seeks excellence in reference to various things; and avarice seeks abundance of things adapted to human use.
1442
Objection: 1. It would seem that spiritual sins are unfittingly distinguished from carnal sins. For the Apostle says (Ga 5,19): "The works of the flesh are manifest, which are fornication, uncleanness, immodesty, luxury, idolatry, witchcrafts," etc. from which it seems that all kinds of sins are works of the flesh. Now carnal sins are called works of the flesh. Therefore carnal sins should not be distinguished from spiritual sins.
2. Further, whosoever sins, walks according to the flesh, as stated in Rm 8,13: "If you live according to the flesh, you shall die. But if by the spirit you mortify the deeds of the flesh, you shall live." Now to live or walk according to the flesh seems to pertain to the nature of carnal sin. Therefore carnal sins should not be distinguished from spiritual sins.
3. Further, the higher part of the soul, which is the mind or reason, is called the spirit, according to Ep 4,23: "Be renewed in the spirit of your mind," where spirit stands for reason, according to a gloss. Now every sin, which is committed in accordance with the flesh, flows from the reason by its consent; since consent in a sinful act belongs to the higher reason, as we shall state further on (Question [74], Article [7]). Therefore the same sins are both carnal and spiritual, and consequently they should not be distinguished from one another.
4. Further, if some sins are carnal specifically, this, seemingly, should apply chiefly to those sins whereby man sins against his own body. But, according to the Apostle (1Co 6,18), "every sin that a man doth, is without the body: but he that committeth fornication, sinneth against his own body." Therefore fornication would be the only carnal sin, whereas the Apostle (Ep 5,3) reckons covetousness with the carnal sins.
On the contrary Gregory (Moral. xxxi, 17) says that "of the seven capital sins five are spiritual, and two carnal."
I answer that As stated above (Article [1]), sins take their species from their objects. Now every sin consists in the desire for some mutable good, for which man has an inordinate desire, and the possession of which gives him inordinate pleasure. Now, as explained above (Question [31], Article [3]), pleasure is twofold. One belongs to the soul, and is consummated in the mere apprehension of a thing possessed in accordance with desire; this can also be called spiritual pleasure, e.g. when one takes pleasure in human praise or the like. The other pleasure is bodily or natural, and is realized in bodily touch, and this can also be called carnal pleasure.Accordingly, those sins which consist in spiritual pleasure, are called spiritual sins; while those which consist in carnal pleasure, are called carnal sins, e.g. gluttony, which consists in the pleasures of the table; and lust, which consists in sexual pleasures. Hence the Apostle says (2Co 7,1): "Let us cleanse ourselves from all defilement of the flesh and of the spirit."
Reply to Objection: 1. As a gloss says on the same passage, these vices are called works of the flesh, not as though they consisted in carnal pleasure; but flesh here denotes man, who is said to live according to the flesh, when he lives according to himself, as Augustine says (De Civ. Dei xiv, 2,3). The reason of this is because every failing in the human reason is due in some way to the carnal sense.
2. This suffices for the Reply to the Second Objection.
3. Even in the carnal sins there is a spiritual act, viz. the act of reason: but the end of these sins, from which they are named, is carnal pleasure.
4. As the gloss says, "in the sin of fornication the soul is the body's slave in a special sense, because at the moment of sinning it can think of nothing else": whereas the pleasure of gluttony, although carnal, does not so utterly absorb the reason. It may also be said that in this sin, an injury is done to the body also, for it is defiled inordinately: wherefore by this sin alone is man said specifically to sin against his body. While covetousness, which is reckoned among the carnal sins, stands here for adultery, which is the unjust appropriation of another's wife. Again, it may be said that the thing in which the covetous man takes pleasure is something bodily, and in this respect covetousness is numbered with the carnal sins: but the pleasure itself does not belong to the body, but to the spirit, wherefore Gregory says (Moral. xxxi, 17) that it is a spiritual sin.
1443
Objection: 1. It would seem that sins differ specifically in reference to their causes. For a thing takes its species from that whence it derives its being. Now sins derive their being from their causes. Therefore they take their species from them also. Therefore they differ specifically in reference to their causes.
2. Further, of all the causes the material cause seems to have least reference to the species. Now the object in a sin is like its material cause. Since, therefore, sins differ specifically according to their objects, it seems that much more do they differ in reference to their other causes.
3. Further, Augustine, commenting on Ps 79,17, "Things set on fire and dug down," says that "every sin is due either to fear inducing false humility, or to love enkindling us to undue ardor." For it is written (1Jn 2,16) that "all that is in the world, is the concupiscence of the flesh, or [Vulg.: 'and'] the concupiscence of the eyes, or [Vulg.: 'and'] the pride of life." Now a thing is said to be in the world on account of sin, in as much as the world denotes lovers of the world, as Augustine observes (Tract. ii in Joan.). Gregory, too (Moral. xxxi, 17), distinguishes all sins according to the seven capital vices. Now all these divisions refer to the causes of sins. Therefore, seemingly, sins differ specifically according to the diversity of their causes.
On the contrary If this were the case all sins would belong to one species, since they are due to one cause. For it is written (Si 10,15) that "pride is the beginning of all sin," and (1Tm 6,10) that "the desire of money is the root of all evils." Now it is evident that there are various species of sins. Therefore sins do not differ specifically according to their different causes.
I answer that Since there are four kinds of causes, they are attributed to various things in various ways. Because the "formal" and the "material" cause regard properly the substance of a thing; and consequently substances differ in respect of their matter and form, both in species and in genus. The "agent" and the "end" regard directly movement and operation: wherefore movements and operations differ specifically in respect of these causes; in different ways, however, because the natural active principles are always determined to the same acts; so that the different species of natural acts are taken not only from the objects, which are the ends or terms of those acts, but also from their active principles: thus heating and cooling are specifically distinct with reference to hot and cold. On the other hand, the active principles in voluntary acts, such as the acts of sins, are not determined, of necessity, to one act, and consequently from one active or motive principle, diverse species of sins can proceed: thus from fear engendering false humility man may proceed to theft, or murder, or to neglect the flock committed to his care; and these same things may proceed from love enkindling to undue ardor. Hence it is evident that sins do not differ specifically according to their various active or motive causes, but only in respect of diversity in the final cause, which is the end and object of the will. For it has been shown above (Question [1], Article [3]; Question [18], Articles [4],6) that human acts take their species from the end.
Reply to Objection: 1. The active principles in voluntary acts, not being determined to one act, do not suffice for the production of human acts, unless the will be determined to one by the intention of the end, as the Philosopher proves (Metaph. ix, text. 15,16), and consequently sin derives both its being and its species from the end.
2. Objects, in relation to external acts, have the character of matter "about which"; but, in relation to the interior act of the will, they have the character of end; and it is owing to this that they give the act its species. Nevertheless, even considered as the matter "about which," they have the character of term, from which movement takes its species (Phys. v, text. 4; Ethic. x, 4); yet even terms of movement specify movements, in so far as term has the character of end.
3. These distinctions of sins are given, not as distinct species of sins, but to show their various causes.
1444
Objection: 1. It would seem that sin is unfittingly divided into sin against God, against one's neighbor, and against oneself. For that which is common to all sins should not be reckoned as a part in the division of sin. But it is common to all sins to be against God: for it is stated in the definition of sin that it is "against God's law," as stated above (Question [66], Article [6]). Therefore sin against God should not be reckoned a part of the division of sin.
2. Further, every division should consist of things in opposition to one another. But these three kinds of sin are not opposed to one another: for whoever sins against his neighbor, sins against himself and against God. Therefore sin is not fittingly divided into these three.
3. Further, specification is not taken from things external. But God and our neighbor are external to us. Therefore sins are not distinguished specifically with regard to them: and consequently sin is unfittingly divided according to these three.
On the contrary Isidore (De Summo Bono), in giving the division of sins, says that "man is said to sin against himself, against God, and against his neighbor."
I answer that As stated above (Question [71], Articles [1],6), sin is an inordinate act. Now there should be a threefold order in man: one in relation to the rule of reason, in so far as all our actions and passions should be commensurate with the rule of reason: another order is in relation to the rule of the Divine Law, whereby man should be directed in all things: and if man were by nature a solitary animal, this twofold order would suffice. But since man is naturally a civic and social animal, as is proved in Polit. i, 2, hence a third order is necessary, whereby man is directed in relation to other men among whom he has to dwell. Of these orders the second contains the first and surpasses it. For whatever things are comprised under the order of reason, are comprised under the order of God Himself. Yet some things are comprised under the order of God, which surpass the human reason, such as matters of faith, and things due to God alone. Hence he that sins in such matters, for instance, by heresy, sacrilege, or blasphemy, is said to sin against God. In like manner, the first order includes the third and surpasses it, because in all things wherein we are directed in reference to our neighbor, we need to be directed according to the order of reason. Yet in some things we are directed according to reason, in relation to ourselves only, and not in reference to our neighbor; and when man sins in these matters, he is said to sin against himself, as is seen in the glutton, the lustful, and the prodigal. But when man sins in matters concerning his neighbor, he is said to sin against his neighbor, as appears in the thief and murderer. Now the things whereby man is directed to God, his neighbor, and himself are diverse. Wherefore this distinction of sins is in respect of their objects, according to which the species of sins are diversified: and consequently this distinction of sins is properly one of different species of sins: because the virtues also, to which sins are opposed, differ specifically in respect of these three. For it is evident from what has been said (Question [62], Articles [1],2,3) that by the theological virtues man is directed to God; by temperance and fortitude, to himself; and by justice to his neighbor.
Reply to Objection: 1. To sin against God is common to all sins, in so far as the order to God includes every human order; but in so far as order to God surpasses the other two orders, sin against God is a special kind of sin.
2. When several things, of which one includes another, are distinct from one another, this distinction is understood to refer, not to the part contained in another, but to that in which one goes beyond another. This may be seen in the division of numbers and figures: for a triangle is distinguished from a four-sided figure not in respect of its being contained thereby, but in respect of that in which it is surpassed thereby: and the same applies to the numbers three and four.
3. Although God and our neighbor are external to the sinner himself, they are not external to the act of sin, but are related to it as to its object.
Summa Th. I-II EN Qu.71 a.3