The Law of Nature Bound People from the Beginning

When God created man, he planted in him by nature a complete knowledge of the law. If man had kept it as at the beginning, according to the Lord’s purpose, there would have been no need for another law to be given, the one God afterward proclaimed in writing. For it would be pointless to offer a remedy from outside where one within was still planted and vigorous. But since, as we have said, this natural law had been utterly corrupted by freedom and the opportunity of sinning, the strict restraints of the law of Moses were added as its executor and enforcer and, to use the expression of Scripture, as its helper. This was so that, through fear of immediate punishment, people might be kept from losing the good of natural knowledge altogether, as the prophet says: “He gave the law to help them.” The apostle also describes the law as given as a guardian to little children, since it instructs and guards them, to keep them from departing through sheer forgetfulness from the teaching they had received by the light of nature. [a]

That a complete knowledge of the law was planted in man at his first creation is clearly proved by this: we know that before the law, and indeed even before the flood, all holy men kept the commands of the law without having its letter to read. For how could Abel, without the command of the law, have known that he ought to offer God a sacrifice of the firstborn of his flock and of their fat, unless he had been taught by the law naturally planted in him? How could Noah have told which animals were clean and which unclean, when the commandment of the law had not yet made the distinction, unless he had been taught by natural knowledge? Where did Enoch learn how to “walk with God,” never having received any light of the law from another? Where had Shem and Japheth read, “You shall not uncover the nakedness of your father,” so that they walked backward and covered their father’s shame? How was Abraham taught to refuse the spoils of the enemy that were offered to him, so as not to receive any reward for his toil, or to pay the priest Melchizedek the tithes that are ordered by the law of Moses? How was it, too, that the same Abraham, and Lot as well, humbly offered acts of kindness and the washing of their feet to passersby and strangers, while the command of the gospel had not yet shone out? Where did Job get such earnestness of faith, such purity of chastity, such knowledge of humility, gentleness, pity and kindness as we do not see now even in those who know the Gospels by heart?

Which of the saints do we read of who did not keep some commandment of the law before the law was given? Which of them failed to keep this: “Hear, O Israel, the Lord your God is one Lord”? Which of them did not fulfill this: “You shall not make for yourself any carved image, nor the likeness of anything that is in heaven or on the earth or under the earth”? Which of them did not observe this: “Honor your father and your mother,” or what follows in the Ten Commandments: “You shall not murder. You shall not commit adultery. You shall not steal. You shall not bear false witness. You shall not covet your neighbor’s wife”? And there were many other things besides, in which they anticipated the commands not only of the law but even of the gospel.