(b) The Beatitudes assigned here are the fourth (Blessed are they that hunger and thirst after justice, for they shall have their fill), which agrees with justice, and the fifth (Blessed are the merciful, for they shall obtain mercy), which is suitable for piety inasmuch as one who finds his love and joy in God as Father will be compassionate to the suffering creatures of God. Like justice, both of these Beatitudes are exercised in reference to the neighbor (see 164).
(c) The Fruits that seem most appropriate here are good will and kindness, which find a sweet joy in purposing and performing services for others. Like justice, these acts have reference to others (163); like piety, they see in their neighbors the children of the same heavenly Father. Thus, justice when alone is guided by prudence; it pays what is due to God as Lord, to man as neighbor; it acts perhaps with pain, but from a sense of duty. But when justice is supernaturally perfected, it is the Spirit of Piety which guides, and which makes one to see in God one’s Father and in man the child of God; even that which is not owed is given from mercy, and there is a hunger and thirst for justice; and in the payment of duty to others there is at last a joy found in the very difficulty itself.
2434. The Commandments of Justice.—The various precepts regarding justice are contained in the Decalogue. For justice consists in the fulfillment of duties towards others whether they be superiors, equals or inferiors. The Ten Commandments sum up these duties of justice; the first three prescribe the duties owed to God, the fourth the duties owed to human superiors, and the other six the obligations which man has to his equals or to all fellowmen.
2435. The order of the Commandments is most appropriate, for their purpose is to form man to virtue and to lead him to perfection, which consists in the love of God and neighbor (see 1118, 1553 sqq.), and they therefore outline first the service that is owed to God (Commandments of the First Table) and next the service that is owed to man (Commandments of the Second Table).
(a) The Commandments of the First Table lay the foundation of the edifice of justice, for they teach us that our first duty is to render to God the things that are God’s. We must avoid, therefore, the excess of superstition (Thou shalt not have strange gods before Me) and the defect of irreligiousness (Thou shalt not take the name of the Lord Thy God in vain); we must practise the virtue of religion (Remember thou keep holy the Sabbath Day).
(b) The Commandments of the Second Table begin with the duties owed to those to whom we are most bound after God, namely, parents, country, superiors (Honor thy father and thy mother). Next follow prohibitions against injuries done to any neighbor by deeds or words, whether the harm be to his person (Thou shalt not kill), or to those who are as one person with him (Thou shalt not commit adultery), or to a neighbor’s external corporal goods (Thou shalt not steal), or to his external incorporeal goods of fame and honor (Thou shalt not bear false witness against thy neighbor). Finally, there are prohibitions against thoughts or desires injurious to the neighbor, mention being made specially of those internal sins that are most common on account of the utility (Thou shalt not covet thy neighbor’s goods) or the pleasure (Thou shalt not covet thy neighbor’s wife) they afford.
2436. We shall not give here any special treatment of the Decalogue. Rather we refer the reader to the excellent explanations that are contained in Part III of The Catechism of the Council of Trent. Moreover, each of the Commandments has been treated in the present work, chiefly in the Articles on justice, and supplementary matter can be drawn from some others of its articles. For the sake of convenience, however, we give here a list of references, showing the passages of this Moral Theology in which the Commandments of the Decalogue are explained.
(a) Thus, for the First Commandment read on superstition (2274 sqq.) for the prohibitory part, on faith, hope and charity (746 sqq.) for the perceptive part.
(b) For the Second Commandment read on irreligiousness (2299) for the prohibitory part; on oaths, adjuration and praise (2245 sqq.) for the preceptive part.
(c) For the Third Commandment as to its natural precept, read on the virtue of religion (2145 sqq.); as to its positive precept, read on positive laws (340 sqq., 352, 425) and on the first Commandment of the Church (see 2575 sqq.).