Section VIII: The Order of the Commandments of the Decalogue, § 54.
SECTION VIII: THE ORDER OF THE COMMANDMENTS OF THE DECALOGUE
§ 54. The elegant arrangement of the commandments of the Decalogue is truly a great proof for the wisdom of God. The commandments of the First Tablet speak about the immediate service [cultus] to God; those of the Second Tablet, about mediate service to God since obligations which must be fulfilled to one’s neighbor should proceed from a genuine love and fear of God. In this way they become pleasing and acceptable services to God. The First Commandment rises from the most noble object—namely, the true God—and it takes for itself the most noble subject—the very heart of man which it commands to adhere to God with true fear, trust, and love. The Second Commandment controls man’s tongue,1 which should praise, invoke, celebrate, and give thanks to God, correctly known on the basis of His Word. If you do not count the heart, the tongue is man’s most noble member, for it is the instrument of the articulated voice which separates man from brute animals. This little bell should ring as it is tolled by the heart’s rope. The Third Commandment establishes the hallowing of the Sabbath—that is, the public worship of God through the ministry of the Word—for it is by this medium that God wants to stir up in man the true knowledge and invocation of Himself.
The Second Tablet, which speaks about responsibilities due to one’s neighbor, arises from that first natural relationship which exists between parents and children. The family relationship [oeconomica societas] is the foundation and seedbed of the state. It is fitting, then, that the Fourth Commandment, which is the first of the Second Tablet, treats honor for parents. The Fifth Commandment protects the life of a human being and defends it against all injuries. The Sixth Commandment keeps inviolate the integrity of marriage. The Seventh keeps inviolate man’s possessions. The Eighth surrounds one’s reputation with a strong rampart and wall. The Ninth requires uprightness of one’s inner emotions toward his neighbor. The Tenth contains the general declaration of the Law, namely, that the Law requires an inner conformity of all one’s powers with God, a conformity so complete that it is not contaminated by even the smallest stain of corrupt concupiscence.
Thomas ([ST,] 1.2., q. 100, art. 5) proceeds in this way:
Just as the commands of human law direct man’s conduct to respect some community, so also the commandments of God’s Law direct man toward a community or state under God. Now, for man to live well in a human community, two things are required: that he behave well toward him who presides over the community and, second, that he behave well also toward the fellow members of the community. The first three commandments explain the principle of loving God and direct man toward it according to the three things a subject owes his master: faithfulness, reverence, and service. Faithfulness consists in not transferring his allegiance to another. Reverence requires that one commit nothing insulting against his master. Service is owed to God in compensation for the benefits that His subjects receive from Him. The rest of the commandments direct man toward his neighbor. There are some neighbors from whom we receive special benefits and to whom we are obligated to give special gratitude. Thus the Fourth Commandment is given about parents, under which we understand “all benefactors.” Generally, a man should not harm any neighbor in deed, word, or thought. Now, harming one’s neighbor in deed happens in three ways: by destroying him in his own person; by destroying him in a related person—especially to the extent that this applies to the procreation of children; or by destroying him in the wealth of his goods in exterior matters. Harming with one’s mouth implies harm through slander. Harming in thought happens through the unlawful concupiscence of the flesh and eyes—the former of which is forbidden by the Ninth Commandment; the latter, by the Tenth.
1 Read linguam with Cotta instead of lingua.