is added the precept about honoring the aged, according to Lev. 19:32:  “Rise up before the hoary head, and honor the person of the aged man”; and likewise all the precepts prescribing the reverence to be observed towards our betters, or kindliness towards our equals or inferiors.  To the fifth commandment, which forbids murder, is added the prohibition of hatred and of any kind of violence inflicted on our neighbor, according to Lev. 19:16:  “Thou shalt not stand against the blood of thy neighbor”:  likewise the prohibition against hating one’s brother (Lev. 19:17):  “Thou shalt not hate thy brother in thy heart.”  To the sixth commandment which forbids adultery, is added the prohibition about whoredom, according to Deut. 23:17:  “There shall be no whore among the daughters of Israel, nor whoremonger among the sons of Israel”; and the prohibition against unnatural sins, according to Lev. 28:22, 23:  “Thou shalt not lie with mankind . . . thou shalt not copulate with any beast.”  To the seventh commandment which prohibits theft, is added the precept forbidding usury, according to Deut. 23:19:  “Thou shalt not lend to thy brother money to usury”; and the prohibition against fraud, according to Deut. 25:13:  “Thou shalt not have divers weights in thy bag”; and universally all prohibitions relating to peculations and larceny.  To the eighth commandment, forbidding false testimony, is added the prohibition against false judgment, according to Ex. 23:2:  “Neither shalt thou yield in judgment, to the opinion of the most part, to stray from the truth”; and the prohibition against lying (Ex. 23:7):  “Thou shalt fly lying,” and the prohibition against detraction, according to Lev. 19:16:  “Thou shalt not be a detractor, nor a whisperer among the people.”  To the other two commandments no further precepts are added, because thereby are forbidden all kinds of evil desires.

Reply Obj. 1:  The precepts of the decalogue are ordained to the love of God and our neighbor as pertaining evidently to our duty towards them; but the other precepts are so ordained as pertaining thereto less evidently.

Reply Obj. 2:  It is in virtue of their institution that the ceremonial and judicial precepts are determinations of the precepts of the decalogue, not by reason of a natural instinct, as in the case of the superadded moral precepts.

Reply Obj. 3:  The precepts of a law are ordained for the common good, as stated above (Q. 90, A. 2).  And since those virtues which direct our conduct towards others pertain directly to the common good, as also does the virtue of chastity, in so far as the generative act conduces to the common good of the species; hence precepts bearing directly on these virtues are given, both in the decalogue and in addition thereto.  As to the act of fortitude there are the order to be given by the commanders in the war, which is undertaken for the common good:  as is clear from Deut. 20:3, where the priest is commanded (to speak thus):  “Be not afraid, do not give back.”  In like manner the prohibition of acts of gluttony is left to paternal admonition, since it is contrary to the good of the household; hence it is said (Deut. 21:20) in the person of parents:  “He slighteth hearing our admonitions, he giveth himself to revelling, and to debauchery and banquetings.” ________________________