With respect to his first thesis, Zanchi offers at proof the variegated worship of God in pagan history. Although no race's culture is so barbaric, or its philosophy so primitive so as to bar entirely the thought that God exists, Zanchi insists that in the area of worship peoples have historically show great divergence, from external offering of idols to a God viewed as corporeal to a true internal, spiritual worship recognizing that God is spirit. Even within a people there is diversity, thus Cicero "came closer to the truth than many other Romans" in advocating an internal, pure, and integral worship of God in his book On the Nature of the Gods (De natura deorum). Similarly, great divergence is seen within a people's history. Thus the Romans "had also been taught by natural law that because God is spirit, he must not be represented or worshipped with idols, a belief that was continued for one hundred seventy years from the founding of Rome." This purity in worship was lost, and thus the "natural law failed their descendants in part," when they incorporated idols in the worship of God. This corruption is discussed by Augustine in his City of God (6.4) and by Plutarch in his Life of Numa Pompilius. Another example of this corruption in morals is in the matter of oaths. At first, the Romans shunned swearing of oaths on the grounds that God's name was holy, but barbarians had no similar piety.
The divergence, corruption, or lack of integrity in the natural law is not limited to the notion of God and his worship. It is also seen in the area of social life. There have been countries where "deception, thievery, and robbery" are not considered evil. (334) Historical examples that may be adduced are the Spartans, who advanced thievery as good. Though Romans punished false witness harshly by throwing perjurers off the Tarpaeian Rock, not all cultures have been severe with lying, and some nations have praised lying. Though the Romans had rigorous view of marriage and incest, the Canaanites might be pointed to as a culture that violated the natural law in the area of marriage and sexual relations, allowing incestuous marriage as a matter of course. Indeed, so pristine were the Roman laws on marriage that "their laws about unlawful marriages were always honored very reverently by Christians so that whatever was lewd to the Romans had to be lewd to them, while whatever was not lewd to the Romans also was not condemned by the Christians as lewd." (335)
The natural law is even seen where there is a variety of customs. The Greeks, for example, considered it unseemly for a man to grow his hair long, and for a woman to keep it short. The Persians, however, did not share this custom. Yet through both cultures, the natural law that "good and proper behavior should be maintained" persisted, though its content was modified by the cultural norms. (335)
All this establishes the validity of Zanchi's thesis that "natural law has not been inscribed equally on the hearts of all people nor is it today, though in the hearts of the elect, of course, it is always more fully and more effectively written as the Lord promised in Jeremiah." (335, referring to Jer. 31:31-34) "From this it is clear that natural law is one and the same among all nations if we look at its presuppositions, not at its conclusions or applications." (335)
Zanchi's penultimate thesis on the natural law is that the law "is so impressed upon the human heart that it cannot be altered by anyone or completely blotted out from the heart." (336) Zanchi explains that God wants all men judged by the same standard, and so the "same law" must "exist inside all people." (336) The law sets forth those standards by which they are convicted as well as those for which they are forgiven if they act justly. It is this feature that St. Augustine in his Confessions refers to when he says: "Your law [has been] written on men's hearts, which iniquity itself cannot blot out" (et lex scripta in cordibus hominum, quam ne ipsa quidem delet iniquitas). Conf., ii.4. For Zanchi, the principles are never blotted out, and they remain there to "prick the human conscience," and thus "convicts human beings of sin." (336) However, the conclusions that come from the fundamental principles of natural law may be "blotted from human hearts when they are handed over to their sins, as Romans 1 proves." (336)
Zanchi completes his analysis of the natural law by equating its content with the Decalogue. "[B]ecause the Decalogue defines and describes the same things that are called natural law," Zanchi states, "the Ten Commandments themselves are often called "natural law." (337) Before going into his discussion of human laws, which "are derived from natural law through human reason," Zanchi closes his treatment of the natural with this gem:
[I]t must be mentioned that just as Christ is the fulfillment of the entire Mosaic law, so, too, is he the fulfillment of the natural law because, as human beings are convicted of sin through the law, they flee to Christ for forgiveness . . . .
There is one statement which appears odd: "Remember that because of Adam's sin, natural law had been destroyed and became an offense but that it is not one now." (336) It is unclear to me exactly what Zanchi intended to communicate by this cryptic statement.
This terminates our discussion on Zanchi's treatment of the natural law, though his treatment on human law, ecclesiastical law, custom and title, divine law, and the law of the spirit, Mosaic law, the law of the Jewish State, and ceremonial laws warrant review. These will be handled in subsequent posts.