A reason is given why this book did not open with a discussion of the above-mentioned virtues. It is also concisely pointed out that the same virtues existed in the ancient fathers.
116. Perhaps, as the different classes of duties are derived from these four virtues, some one may say that they ought to have been described first of all. But it would have been artificial to have given a definition of duty at the outset, and then to have gone on to divide it up into various classes. We have avoided what is artificial, and have put forward the examples of the fathers of old. These certainly offer us no uncertainty as regards our understanding them, and give us no room for subtlety in our discussion of them. Let the life of the fathers, then, be for us a mirror of virtue, not a mere collection of shrewd and clever acts. Let us show reverence in following them, not mere cleverness in discussing them.
117. Prudence held the first place in holy Abraham. For of him the Scriptures say: “Abraham believed God, and that was counted to him for righteousness;” for no one is prudent who knows not God. Again: “The fool has said, There is no God;” for a wise man would not say so. How is he wise who looks not for his Maker, but says to a stone: “You are my father”? Who says to the devil as the Manichæan does: “You are the author of my being”? How is Arius wise, who prefers an imperfect and inferior creator to one who is a true and perfect one? How can Marcion or Eunomius be wise, who prefer to have an evil rather than a good God? And how can he be wise who does not fear his God? For: “The fear of the Lord is the beginning of wisdom.” Elsewhere, too, it stands: “The wise turn not aside from the mouth of the Lord, but come near Him in their confession of His greatness.” So when the Scripture says: “It was counted to him for righteousness,” that brought to him the grace of another virtue.
118. The chief among ourselves have stated that prudence lies in the knowledge of the truth. But who of them all excelled Abraham, David, or Solomon in this? Then they go on to say that justice has regard to the whole community of the human race. So David said: “He has dispersed abroad and given to the poor, His righteousness remains for ever.” The just man has pity, the just man lends. The whole world of riches lies at the feet of the wise and the just. The just man regards what belongs to all as his own, and his own as common property. The man just accuses himself rather than others. For he is just who does not spare himself, and who does not suffer his secret actions to be concealed. See now how just Abraham was! In his old age he begot a son according to promise, and when the Lord demanded him for sacrifice he did not think he ought to refuse him, although he was his only son.
119. Note here all these four virtues in one act. It was wise to believe God, and not to put love for his son before the commands of his Creator. It was just to give back what had been received. It was brave to restrain natural feelings by reason. The father led the victim; the son asked where it was: the father's feelings were hardly tried, but were not overcome. The son said again: “My father,” and thus pierced his father's heart, though without weakening his devotion to God. The fourth virtue, temperance, too, was there. Being just he preserved due measure in his piety, and order in all he had to carry out. And so in bringing what was needed for the sacrifice, in lighting the fire, in binding his son, in drawing the knife, in performing the sacrifice in due order; thus he merited as his reward that he might keep his son.
120. Is there greater wisdom than holy Jacob's, who saw God face to face and won a blessing? Can there be higher justice than his in dividing with his brother what he had acquired, and offering it as a gift? What greater fortitude than his in striving with God? What moderation so true as his, who acted with such moderation as regards time and place, as to prefer to hide his daughter's shame rather than to avenge himself? For being set in the midst of foes, he thought it better to gain their affections than to concentrate their hate on himself.
121. How wise also was Noah, who built the whole of the ark! How just again! For he alone, preserved of all to be the father of the human race, was made a survivor of past generations, and the author of one to come; he was born, too, rather for the world and the universe than for himself. How brave he was to overcome the flood! How temperate to endure it! When he had entered the ark, with what moderation he passed the time! When he sent forth the raven and the dove, when he received them on their return, when he took the opportunity of leaving the ark, with what moderation did he make use of these occasions!
Source: On the Duties of the Clergy (New Advent)