11. Second, transgressors of the commandments plunge into abominable crimes: whence in Baruch: We have not obeyed the voice of the Lord, that we should walk in His commandments, and we have gone away each one into the sense of his own malicious heart. Of such transgressors the Psalm says: My people did not hear My voice, and Israel did not attend to Me, and I dismissed them according to the desires of their hearts. For the Lord delivers such transgressors into the hands of demons. This was well signified in the third chapter of Daniel, where it is said that the three youths standing in the furnace of fire said: We have sinned and acted wickedly and transgressed; there follows: And we have been delivered into the hands of our enemies, wicked and most vile transgressors, and to a king unjust and most wicked beyond all the earth.
12. Third, transgressors of the commandments merit eternal punishments: the Psalm: Cursed are they who decline from Thy commandments: cursed, because it shall be said to them: Depart, ye cursed, into everlasting fire, Matthew twenty-five.
13. Behold, the wondrous benefit of observance and the wondrous calamity of transgression. Whence the Lord through Moses: Behold, He says, I set before thee blessing and curse: blessing, if thou shalt keep My commandments: curse, if thou shalt not keep them. The Lord places us in the middle and works with us wonderfully.
When someone wishes to demonstrate something to another, he proceeds against him by a twofold way, namely by ostensive reasoning and by reasoning leading to an impossibility . Thus does the Lord: He places man in the middle between heaven and hell: in heaven is eternal glory, in hell are eternal punishments. And when the Lord shows man the glory of paradise, which he can merit by keeping the commandments, then He inclines him to the observance of the commandments by ostensive reasoning. But when He shows him the punishments of hell, into which he will fall if he transgresses the commandments, then He inclines him by reasoning leading to an impossibility.
Behold, He sets before us curse and blessing; let us leave to Judas the traitor the curse and the snares, of whom it is said that he did not will blessing, and it shall be far from him; and let us with blessed Matthias receive the blessing.
14. Fourth, what ought to move us to the observance of the commandments is the irreproachability of the commandments. A commandment is called irreproachable when it contains nothing impossible, nor anything burdensome, nor anything unjust. So it is with the commandments of God.
15. First, I say, the commandments of God are irreproachable, because they contain nothing impossible: whence in First John: This is the love of God, that we keep his commandments, and his commandments are not burdensome. He premises: this is the love of God: for to one having charity the commandments of God are easy and sweet, but to one not having charity they seem difficult. And Augustine gives the example of a bird having feathers and a bird without feathers: and he says that for a bird having feathers it is easy to fly, but for a bird not having feathers it is difficult. Similarly, to a man of perverse will the commandments seem difficult, which to one having charity are easy. Whence it is said in Deuteronomy: This commandment which I command you today is not above you nor placed far off nor set in heaven nor placed beyond the sea, but the word is very near to you, in your mouth and in your heart, that you may do it.
16. Second, the commandments of God are irreproachable, because they contain nothing burdensome, but rather they are sweet. Whence it is said in Ecclesiasticus: Nothing is better than the fear of God, and nothing is sweeter than to look upon the commandments of the Lord: the Psalm: More to be desired than gold and much precious stone, and sweeter than honey and the honeycomb. It is joy to the just to do judgment, that is, justice. But we see that to an infected palate sweet food seems bitter; similarly, to a man of perverse will the commandments of God, which are easy and sweet, seem difficult.
17. Third, the commandments of God are irreproachable, because they contain nothing unjust: whence the Apostle: The law indeed is holy, and the commandment holy and just and good. On account of this he says elsewhere: I command you before God, who gives life to all things, that you keep the commandment without stain, irreproachable.
Therefore the irreproachability of the commandments is now evident.
18. Let us therefore join together these four, namely the authority of the one commanding, the usefulness of observance, the danger of transgression, and the irreproachability of the commandments: and we shall see that there is no one who will be able to excuse himself from the observance of the precepts.
19. But which is the first and great commandment in the Law? The Lord responds in Matthew: You shall love the Lord your God with your whole heart and with your whole soul and with your whole mind. This is the greatest and first commandment. And the second is like it: you shall love your neighbor as yourself. On these two the whole Law and the Prophets depend. Augustine shows that in this word: But it is good for me to adhere to God, the whole of what is said is contained: You shall love the Lord your God, etc. For we ought to love God, because this is just, holy, easy, and sweet. Whence Augustine: "Lord, who are you to me? And who am I to you, that you command me to love you, and if I do not love you, you threaten me with immense miseries?"
20. Moreover, the sacred decalogue, which was given to Moses on Mount Sinai, shows how we ought to keep the commandments of God: and I wish to show you that just as there are eight parts of speech, which are the foundation of all things that can be expressed by voice in grammar, and just as there are ten categories, which are the foundation of all things that are determined in dialectic: so the ten precepts are the foundation of all laws and divine commandments. For the Lord willed that they were not given to Moses without reason. - I shall now state these precepts in general:
Thou shalt not have strange gods.
Thou shalt not take the name of thy God in vain.
Remember to keep holy the Sabbath day.
Honor thy father and thy mother.
Thou shalt not kill.
Thou shalt not commit adultery.
Thou shalt not steal.
Thou shalt not bear false witness.
Thou shalt not covet thy neighbor's wife.
Nor any thing that is his.
21. And it should be noted that every law commands nothing but justice. For law is the rule of justice; and justice is that according to which man is to be ordered toward God and toward neighbor. According to this there is a twofold justice: one, by which we are ordered toward God; another, by which we are ordered toward neighbor; and according to this two tablets were given to Moses, namely the first and the second. In the first are contained the commandments ordering us toward God; in the second are contained the commandments ordering us toward neighbor.
22. In the first tablet, I say, are contained the commandments ordering us toward God: but God is the Trinity, Father and Son and Holy Spirit. To the Father is attributed majesty, to the Son truth, and to the Holy Spirit goodness. In the Father there is supreme majesty to be humbly adored; in the Son there is supreme truth to be faithfully asserted; in the Holy Spirit there is supreme goodness to be sincerely loved. But if we ought to do these three things by eternal ordination, then it is necessary that in the first tablet there be three commandments according to these three things appropriated to the three divine persons. In the first commandment indeed is commanded the humble adoration of divine majesty, when it is said: Thou shalt not have strange gods. In the second commandment is commanded the faithful assertion of divine truth, when it is said: Thou shalt not take the name of thy God in vain. In the third is commanded the sincere love of divine goodness, when it is said: Remember to keep holy the Sabbath day. These are the three commandments of the first tablet.