Heinrich Bullinger, the Swiss successor of Zwingli, says that the natural law is an act of the conscience and an innate knowledge of good and evil. This is similar to Thomas Aquinas’s view of the natural law, the conscience is an act and synderesis is a habit of knowledge of the difference between good and evil, the principle which provides the foundation of the law of nature. Yet, where Thomas emphasized the whole faculty of reason and the necessity of virtue, Bullinger places emphasis upon the act of conscience in accusing and excusing the acts of man. This emphasis upon the intellect over the will does not mean that Bullinger de-emphasized or overlooked the role of the desiring faculty or the necessity of virtue in the natural law. He simply attributes the moving of men toward good things to the inspiration of God that comes by means of the conscience. He also attributes the natural law itself to God’s work in men’s souls:
The law of nature is an instruction of the conscience, and, as it were, a certain direction placed by God himself in the mind and hearts of men, to teach them what they have to do and what to eschew. And the conscience, verily, is the knowledge, judgment, and reason of a man, whereby every man in himself, and in his own mind, being made privy to everything that he either hath committed or not committed, doth either condemn or else acquit himself. And this reason proceedeth from God, who both prompteth and writeth his judgments in the hearts and minds of men. Moreover, that which we call nature is the proper disposition or inclination of every thing. But the disposition of mankind being flatly corrupted by sin, as it is blind, so also is it in all points evil and naughty. It knoweth not God, it worshippeth not God, neither doth it love the neighbour; but rather is affected with self-love toward itself, and seeketh still for its own advantage. For which cause the apostle said, “that we by nature are the children of wrath.” Wherefore the law of nature is not called the law of nature, because in the nature and disposition of man there is of or by itself that reason of light exhorting to the best things, and that holy working; but for because God hath imprinted or engraven in our minds some knowledge, and certain general principles of religion, justice, and goodness, which, because they be grafted in us and born together with us, do therefore seem to be naturally in us. (Decades, II.194.)
The Reformers tended to answer the apparent discrepancy between Plato’s idealism and Aristotle’s empiricism by referring to the narrative of Genesis three, where the representatives of the human race fell from their upright state by sinning against the will of God. In the Garden of Eden, Adam had innate knowledge and virtues. Yet, these gifts were not “natural” in the sense that they were produced solely by nature but they were “natural” in the sense that Adam was created with these gifts. They were not added later. After the fall, and because of original sin, men are no longer born with supernatural virtue or knowledge, yet, God does continue to write his law upon men’s hearts – both Melanchthon and Vermigli follow the Stoic notion of prolepseis, or precognitions that stir men up to think on divine things. So, just as Adam’s gifts were not produced by nature in the beginning, much less may this knowledge be produced by nature after nature has become corrupt. Bullinger, in the above statement, appears to present this same resolution between the two concepts of innate and acquired knowledge. The natural law cannot come from nature because of the corruption of original sin. Yet, Bullinger seems to display a rather extreme doctrine of original sin in this passage. He notes that man’s nature, defined as “the proper disposition or inclination of every thing,” has been so corrupted by sin that reason no longer functions, leaving men utterly evil and debauched. And, because of this corruption the law of nature can only exist if God so delights to write it upon the hearts of men – these principles are written upon the hearts of all men by God and only seem to be natural.
I do not think Bullinger is truly saying that after the fall man’s nature was so corrupt that the very faculty that distinguishes man from beast was lost, that reason no longer held any directive power over the passions. Other Reformers such as Calvin and Vermigli hold to a less than optimistic view of original sin, but even they admit that man’s reason has been preserved from utter destruction, to the extent that even pagans may regulate their passions to the common good of society. Bullinger is being somewhat polemical in concert with Augustine’s condemnation of pagan virtue as “splendid vices.” He is viewing the first table of the law from the perspective of the second. In other words, he is speaking of the potentialities of nature in the City of Man from the perspective of the City of God. Viewed from this perspective, and the boasts of the City of Man that claims a purely autonomous path to perfection, the law of nature is utterly destroyed by the Fall. This is the case because the natural law originally guided man toward his supernatural goal, but after the fall man pursues whatever seems right in his own eyes. So, the pagans would know nothing of God or the difference between good and evil if God did not form the souls of men with these principles from the instant of their creation. Therefore, the City of Man cannot boast in an autonomous acquisition of this knowledge since these principles have been given to it by God. Bullinger seeks to keep Aristotle’s principles of acquired virtue and knowledge while at them same time safeguarding the Biblical doctrine of original sin and innate knowledge of God. He continues, explaining how this law is written in man’s nature:
But in what sort have they it [the law of nature] in themselves? This again is made manifest by that which followeth: “For they shew the work of the law written in their hearts.” But who is he that writeth in their hearts, but God alone, who is the searcher of all hearts? And what, I pray you, writeth he there? The law of nature, forsooth; the law, I say, itself, commanding good and forbidding evil, so that without the written law, by the instruction of nature, that is, by the knowledge imprinted of God in nature, they may understand what is good and what is evil , what is to be desired and what is to be shunned. By these words of the apostle we do understand, that the law of nature is set against the written law of God; and that therefore is is called the law of nature, because it seemeth to be, as it were, placed or graffed in nature. We understand, that the law of nature, not the written law, but that which is graffed in man, hath the same office that the written law hath; I mean, to direct men, and to teach them, and also to discern betwixt good and evil, and to be able to judge of sin. We understand, that the beginning of this law is not to the corrupt disposition of mankind, but of God himself, who with his finger writeth in our hearts, fasteneth in our nature, and planteth in us a rule to know justice, equity, and goodness. (ibid.)
Thus, this law is perfectly natural, just like every good with which man is adorned. But, in order to stay in line with the Aristotelian notion of acquired good while maintaining the Pauline notion of natural corruption, we must not speak of this law as natural. God has given us these moral principles to lead us back to him, and they are ours, but as a corrupt nature cannot begin to lead man to do good things without the hand of God molding it and adorning it with knowledge of good and evil, so the Gentiles would have an utterly depraved nature were it not for the common grace of God.