On the contrary, It is written ( Dt. 6:1 ): "These are the precepts and ceremonies and judgments which the Lord your God commanded . . . you." And these words are placed at the beginning of the Law. Therefore all the precepts of the Law are included under them.
I answer that, Some things are included in the Law by way of precept; other things, as being ordained to the fulfilment of the precepts. Now the precepts refer to things which have to be done: and to their fulfilment man is induced by two considerations, viz. the authority of the lawgiver, and the benefit derived from the fulfilment, which benefit consists in the attainment of some good, useful, pleasurable or virtuous, or in the avoidance of some contrary evil. Hence it was necessary that in the Old Law certain things should be set forth to indicate the authority of God the lawgiver: e.g. Dt. 6:4 : "Hear, O Israel, the Lord our God is one Lord"; and Gn. 1:1 : "In the beginning God created heaven and earth": and these are called "testimonies." Again it was necessary that in the Law certain rewards should be appointed for those who observe the Law, and punishments for those who transgress; as it may be seen in Dt. 28 : "If thou wilt hear the voice of the Lord thy God . . . He will make thee higher than all the nations," etc.: and these are called "justifications," according as God punishes or rewards certain ones justly.
The things that have to be done do not come under the precept except in so far as they have the character of a duty. Now a duty is twofold: one according to the rule of reason; the other according to the rule of a law which prescribes that duty: thus the Philosopher distinguishes a twofold just---moral and legal (Ethic. v, 7).
Moral duty is twofold: because reason dictates that something must be done, either as being so necessary that without it the order of virtue would be destroyed; or as being useful for the better maintaining of the order of virtue. And in this sense some of the moral precepts are expressed by way of absolute command or prohibition, as "Thou shalt not kill, Thou shalt not steal": and these are properly called "precepts." Other things are prescribed or forbidden, not as an absolute duty, but as something better to be done. These may be called "commandments"; because they are expressed by way of inducement and persuasion: an example whereof is seen in Ex. 22:26 : "If thou take of thy neighbor a garment in pledge, thou shalt give it him again before sunset"; and in other like cases. Wherefore Jerome (Praefat. in Comment. super Marc.) says that "justice is in the precepts, charity in the commandments." Duty as fixed by the Law, belongs to the judicial precepts, as regards human affairs; to the "ceremonial" precepts, as regards Divine matters.
Nevertheless those ordinances also which refer to punishments and rewards may be called "testimonies," in so far as they testify to the Divine justice. Again all the precepts of the Law may be styled "justifications," as being executions of legal justice. Furthermore the commandments may be distinguished from the precepts, so that those things be called "precepts" which God Himself prescribed; and those things "commandments" which He enjoined [mandavit] through others, as the very word seems to denote.
From this it is clear that all the precepts of the Law are either moral, ceremonial, or judicial; and that other ordinances have not the character of a precept, but are directed to the observance of the precepts, as stated above.
Reply to Objection 1: Justice alone, of all the virtues, implies the notion of duty. Consequently moral matters are determinable by law in so far as they belong to justice: of which virtue religion is a part, as Tully says (De Invent. ii). Wherefore the legal just cannot be anything foreign to the ceremonial and judicial precepts.
The Replies to the other Objections are clear from what has been said.
Whether the Old Law should have induced men to the observance of its precepts, by means of temporal promises and threats?
Objection 1: It would seem that the Old Law should not have induced men to the observance of its precepts, by means of temporal promises and threats. For the purpose of the Divine law is to subject man to God by fear and love: hence it is written ( Dt. 10:12 ): "And now, Israel, what doth the Lord thy God require of thee, but that thou fear the Lord thy God, and walk in His ways, and love Him?" But the desire for temporal goods leads man away from God: for Augustine says (Qq. lxxxiii, qu. 36), that "covetousness is the bane of charity." Therefore temporal promises and threats seem to be contrary to the intention of a lawgiver: and this makes a law worthy of rejection, as the Philosopher declares (Polit. ii, 6).
Objection 2: Further, the Divine law is more excellent than human law. Now, in sciences, we notice that the loftier the science, the higher the means of persuasion that it employs. Therefore, since human law employs temporal threats and promises, as means of persuading man, the Divine law should have used, not these, but more lofty means.
Objection 3: Further, the reward of righteousness and the punishment of guilt cannot be that which befalls equally the good and the wicked. But as stated in Eccles. 9:2, "all" temporal "things equally happen to the just and to the wicked, to the good and the evil, to the clean and to the unclean, to him that offereth victims, and to him that despiseth sacrifices." Therefore temporal goods or evils are not suitably set forth as punishments or rewards of the commandments of the Divine law.
On the contrary, It is written ( Isa. 1:19 , 20 ): "If you be willing, and will hearken to Me, you shall eat the good things of the land. But if you will not, and will provoke Me to wrath: the sword shall devour you."
I answer that, As in speculative sciences men are persuaded to assent to the conclusions by means of syllogistic arguments, so too in every law, men are persuaded to observe its precepts by means of punishments and rewards. Now it is to be observed that, in speculative sciences, the means of persuasion are adapted to the conditions of the pupil: wherefore the process of argument in sciences should be ordered becomingly, so that the instruction is based on principles more generally known. And thus also he who would persuade a man to the observance of any precepts, needs to move him at first by things for which he has an affection; just as children are induced to do something, by means of little childish gifts. Now it has been said above (Q[98], AA[1],2,3) that the Old Law disposed men to (the coming of) Christ, as the imperfect in comparison disposes to the perfect, wherefore it was given to a people as yet imperfect in comparison to the perfection which was to result from Christ's coming: and for this reason, that people is compared to a child that is still under a pedagogue ( Gal. 3:24 ). But the perfection of man consists in his despising temporal things and cleaving to things spiritual, as is clear from the words of the Apostle ( Phil. 3:13 , 15 ): "Forgetting the things that are behind, I stretch [Vulg.: 'and stretching'] forth myself to those that are before . . . Let us therefore, as many as are perfect, be thus minded." Those who are yet imperfect desire temporal goods, albeit in subordination to God: whereas the perverse place their end in temporalities. It was therefore fitting that the Old Law should conduct men to God by means of temporal goods for which the imperfect have an affection.
Reply to Objection 1: Covetousness whereby man places his end in temporalities, is the bane of charity. But the attainment of temporal goods which man desires in subordination to God is a road leading the imperfect to the love of God, according to Ps. 48:19 : "He will praise Thee, when Thou shalt do well to him."
Reply to Objection 2: Human law persuades men by means of temporal rewards or punishments to be inflicted by men: whereas the Divine law persuades men by meas of rewards or punishments to be received from God. In this respect it employs higher means.
Reply to Objection 3: As any one can see, who reads carefully the story of the Old Testament, the common weal of the people prospered under the Law as long as they obeyed it; and as soon as they departed from the precepts of the Law they were overtaken by many calamities. But certain individuals, although they observed the justice of the Law, met with misfortunes---either because they had already become spiritual (so that misfortune might withdraw them all the more from attachment to temporal things, and that their virtue might be tried)---or because, while outwardly fulfilling the works of the Law, their heart was altogether fixed on temporal goods, and far removed from God, according to Is. 29:13 ( Mat. 15:8 ): "This people honoreth Me with their lips; but their hearts is far from Me."