Objection 3: Further, every law is made for the common good, as Isidore says (Etym. v, 21). But of all the virtues justice alone regards the common good, as the Philosopher says (Ethic. v, 1). Therefore the moral precepts are only about the acts of justice.
On the contrary, Ambrose says (De Paradiso viii) that "a sin is a transgression of the Divine law, and a disobedience to the commandments of heaven." But there are sins contrary to all the acts of virtue. Therefore it belongs to Divine law to direct all the acts of virtue.
I answer that, Since the precepts of the Law are ordained to the common good, as stated above (Q[90], A[2]), the precepts of the Law must needs be diversified according to the various kinds of community: hence the Philosopher (Polit. iv, 1) teaches that the laws which are made in a state which is ruled by a king must be different from the laws of a state which is ruled by the people, or by a few powerful men in the state. Now human law is ordained for one kind of community, and the Divine law for another kind. Because human law is ordained for the civil community, implying mutual duties of man and his fellows: and men are ordained to one another by outward acts, whereby men live in communion with one another. This life in common of man with man pertains to justice, whose proper function consists in directing the human community. Wherefore human law makes precepts only about acts of justice; and if it commands acts of other virtues, this is only in so far as they assume the nature of justice, as the Philosopher explains (Ethic. v, 1).
But the community for which the Divine law is ordained, is that of men in relation to God, either in this life or in the life to come. And therefore the Divine law proposes precepts about all those matters whereby men are well ordered in their relations to God. Now man is united to God by his reason or mind, in which is God's image. Wherefore the Divine law proposes precepts about all those matters whereby human reason is well ordered. But this is effected by the acts of all the virtues: since the intellectual virtues set in good order the acts of the reason in themselves: while the moral virtues set in good order the acts of the reason in reference to the interior passions and exterior actions. It is therefore evident that the Divine law fittingly proposes precepts about the acts of all the virtues: yet so that certain matters, without which the order of virtue, which is the order of reason, cannot even exist, come under an obligation of precept; while other matters, which pertain to the well-being of perfect virtue, come under an admonition of counsel.
Reply to Objection 1: The fulfilment of the commandments of the Law, even of those which are about the acts of the other virtues, has the character of justification, inasmuch as it is just that man should obey God: or again, inasmuch as it is just that all that belongs to man should be subject to reason.
Reply to Objection 2: Justice properly so called regards the duty of one man to another: but all the other virtues regard the duty of the lower powers to reason. It is in relation to this latter duty that the Philosopher speaks (Ethic. v, 11) of a kind of metaphorical justice.
The Reply to the Third Objection is clear from what has been said about the different kinds of community.
Whether all the moral precepts of the Old Law are reducible to the ten precepts of the decalogue?
Objection 1: It would seem that not all the moral precepts of the Old Law are reducible to the ten precepts of the decalogue. For the first and principal precepts of the Law are, "Thou shalt love the Lord thy God," and "Thou shalt love thy neighbor," as stated in Matt. 22:37 , 39 But these two are not contained in the precepts of the decalogue. Therefore not all the moral precepts are contained in the precepts of the decalogue.
Objection 2: Further, the moral precepts are not reducible to the ceremonial precepts, but rather vice versa. But among the precepts of the decalogue, one is ceremonial, viz. "Remember that thou keep holy the Sabbath-day." Therefore the moral precepts are not reducible to all the precepts of the decalogue.
Objection 3: Further, the moral precepts are about all the acts of virtue. But among the precepts of the decalogue are only such as regard acts of justice; as may be seen by going through them all. Therefore the precepts of the decalogue do not include all the moral precepts.
On the contrary, The gloss on Mat. 5:11 : "Blessed are ye when they shall revile you," etc. says that "Moses, after propounding the ten precepts, set them out in detail." Therefore all the precepts of the Law are so many parts of the precepts of the decalogue.
I answer that, The precepts of the decalogue differ from the other precepts of the Law, in the fact that God Himself is said to have given the precepts of the decalogue; whereas He gave the other precepts to the people through Moses. Wherefore the decalogue includes those precepts the knowledge of which man has immediately from God. Such are those which with but slight reflection can be gathered at once from the first general principles: and those also which become known to man immediately through divinely infused faith. Consequently two kinds of precepts are not reckoned among the precepts of the decalogue: viz. first general principles, for they need no further promulgation after being once imprinted on the natural reason to which they are self-evident; as, for instance, that one should do evil to no man, and other similar principles: and again those which the careful reflection of wise men shows to be in accord with reason; since the people receive these principles from God, through being taught by wise men. Nevertheless both kinds of precepts are contained in the precepts of the decalogue; yet in different ways. For the first general principles are contained in them, as principles in their proximate conclusions; while those which are known through wise men are contained, conversely, as conclusions in their principles.
Reply to Objection 1: Those two principles are the first general principles of the natural law, and are self-evident to human reason, either through nature or through faith. Wherefore all the precepts of the decalogue are referred to these, as conclusions to general principles.
Reply to Objection 2: The precept of the Sabbath observance is moral in one respect, in so far as it commands man to give some time to the things of God, according to Ps. 45:11 : "Be still and see that I am God." In this respect it is placed among the precepts of the decalogue: but not as to the fixing of the time, in which respect it is a ceremonial precept.
Reply to Objection 3: The notion of duty is not so patent in the other virtues as it is in justice. Hence the precepts about the acts of the other virtues are not so well known to the people as are the precepts about acts of justice. Wherefore the acts of justice especially come under the precepts of the decalogue, which are the primary elements of the Law.
Whether the precepts of the decalogue are suitably distinguished from one another?
Objection 1: It would seem that the precepts of the decalogue are unsuitably distinguished from one another. For worship is a virtue distinct from faith. Now the precepts are about acts of virtue. But that which is said at the beginning of the decalogue, "Thou shalt not have strange gods before Me," belongs to faith: and that which is added, "Thou shalt not make . . . any graven thing," etc. belongs to worship. Therefore these are not one precept, as Augustine asserts (Qq. in Exod. qu. lxxi), but two.
Objection 2: Further, the affirmative precepts in the Law are distinct from the negative precepts; e.g. "Honor thy father and thy mother," and, "Thou shalt not kill." But this, "I am the Lord thy God," is affirmative: and that which follows, "Thou shalt not have strange gods before Me," is negative. Therefore these are two precepts, and do not, as Augustine says (Qq. in Exod. qu. lxxi), make one.
Objection 3: Further, the Apostle says ( Rom. 7:7 ): "I had not known concupiscence, if the Law did not say: 'Thou shalt not covet.'" Hence it seems that this precept, "Thou shalt not covet," is one precept; and, therefore, should not be divided into two.
On the contrary, stands the authority of Augustine who, in commenting on Exodus (Qq. in Exod. qu. lxxi) distinguishes three precepts as referring to God, and seven as referring to our neighbor.
I answer that, The precepts of the decalogue are differently divided by different authorities. For Hesychius commenting on Lev. 26:26, "Ten women shall bake your bread in one oven," says that the precept of the Sabbath-day observance is not one of the ten precepts, because its observance, in the letter, is not binding for all time. But he distinguishes four precepts pertaining to God, the first being, "I am the Lord thy God"; the second, "Thou shalt not have strange gods before Me," (thus also Jerome distinguishes these two precepts, in his commentary on Osee 10:10, "On thy" [Vulg.: "their"] "two iniquities"); the third precept according to him is, "Thou shalt not make to thyself any graven thing"; and the fourth, "Thou shalt not take the name of the Lord thy God in vain." He states that there are six precepts pertaining to our neighbor; the first, "Honor thy father and thy mother"; the second, "Thou shalt not kill"; the third, "Thou shalt not commit adultery"; the fourth, "Thou shalt not steal"; the fifth, "Thou shalt not bear false witness"; the sixth, "Thou shalt not covet."
But, in the first place, it seems unbecoming for the precept of the Sabbath-day observance to be put among the precepts of the decalogue, if it nowise belonged to the decalogue. Secondly, because, since it is written ( Mat. 6:24 ), "No man can serve two masters," the two statements, "I am the Lord thy God," and, "Thou shalt not have strange gods before Me" seem to be of the same nature and to form one precept. Hence Origen (Hom. viii in Exod.) who also distinguishes four precepts as referring to God, unites these two under one precept; and reckons in the second place, "Thou shalt not make . . . any graven thing"; as third, "Thou shalt not take the name of the Lord thy God in vain"; and as fourth, "Remember that thou keep holy the Sabbath-day." The other six he reckons in the same way as Hesychius.
Since, however, the making of graven things or the likeness of anything is not forbidden except as to the point of their being worshipped as gods---for God commanded an image of the Seraphim [Vulg.: Cherubim] to be made and placed in the tabernacle, as related in Ex. 25:18 ---Augustine more fittingly unites these two, "Thou shalt not have strange gods before Me," and, "Thou shalt not make . . . any graven thing," into one precept. Likewise to covet another's wife, for the purpose of carnal knowledge, belongs to the concupiscence of the flesh; whereas, to covet other things, which are desired for the purpose of possession, belongs to the concupiscence of the eyes; wherefore Augustine reckons as distinct precepts, that which forbids the coveting of another's goods, and that which prohibits the coveting of another's wife. Thus he distinguishes three precepts as referring to God, and seven as referring to our neighbor. And this is better.
Reply to Objection 1: Worship is merely a declaration of faith: wherefore the precepts about worship should not be reckoned as distinct from those about faith. Nevertheless precepts should be given about worship rather than about faith, because the precept about faith is presupposed to the precepts of the decalogue, as is also the precept of charity. For just as the first general principles of the natural law are self-evident to a subject having natural reason, and need no promulgation; so also to believe in God is a first and self-evident principle to a subject possessed of faith: "for he that cometh to God, must believe that He is" ( Heb. 11:6 ). Hence it needs no other promulgation that the infusion of faith.