I’ve just now taken notice of these discussions by Stephen Grabill on natural law and Protestant catholicism. These are excellent surveys in which the catholic nature of the Reformation is thoroughly demonstrated. Grabill quotes Zanchi’s complex definition of natural law:
Natural law is the will of God, and consequently, the divine rule and principle for knowing what to do and what not to do. It is, the knowledge of what is good or bad, fair or unfair, upright or shameful, that was inscribed upon the hearts of all people by God himself also after the fall. For this reason, we are all universally taught what activities should be pursued and what should be avoided; that is, to do one thing and to avoid another, and we know that we are obligated and pushed to act for the glory of God, our own good, and the welfare of our neighbor both in private and in public. In addition, we know that if we do what should be avoided or avoid what we should do, we are condemned; but if we do the opposite, we are defended and absolved. (Girolamo Zanchi, quoted by Stephen Grabill, “Part VI: Recovering and Reviving the Catholicity of Protestant Ethics” at percaritatem.com)
One interesting thing to note in this definition, as Grabill points out, is the fact that God inscribes the natural law upon the hearts of man again after the fall. Thus, Zanchi does not use the doctrine of a natural law merely for the explanation of the acts of certain noble pagans and civilizations but this “divine principle for knowing what to do” also sparks a passion that pushes men toward God.
When I write this Confession of faith, I write everie thing uppon a good conscience, and as I beleeved, so I spake freelie, as the holie scriptures doe teach that wee ought to doe. My faith is grounded simplie and principallie on the word of God and next, somewhat upon the common consent of the whole auncient catholicke church, if it doe not gainsaye the holie scriptures. For I beleeve that the thinges which were decreed and received of the fathers, by common consent of them all gathered together in the name of the Lord, without anie contradiction of holie scriptures, that they also (though they bee not of equall authoritie with the scriptures) come from the Holie ghost. Hereupon it is that the thinges which are of this sorte, I neither will nore dare disproove with a good conscience. And what is more certaine out of the histories, the councells and writings of all the fathers, then that those orders of ministers [primarily bishops], of which wee spake, were ordained and received in the church by common consent of all the whole christian common wealth? And who am I that I should disproove that which the whole church hath approoved? Neither have all the learned men of this age dared to disproove the same, as knowing both that the church might lawfullie doe so [create new ecclesiastical offices] and that all those thinges were ordained and done uppon a godlie purpose and to excellent good endes, for edification of God’s children. (De religione christiana fides, Obs. In caput XXV, Aph. X, et XI.)
In the context of this aphorism Zanchius is defending his earlier statement that even though the office of bishop, as it was understood by the early and Medieval church, is not contained within the scriptures the church may use that office or create others in order to meet the needs of a particular area. Zanchius notes that the scriptural “three-office” view is preferable. The true worth of this quote, however, lies with his general rule of doctrine: the teachings of the fathers which were held unanimously and which do not contradict Holy Scripture come from the Holy Spirit and may not be contradicted with a good conscience.
I found the following quote from Zanchius interesting, partly because Peter Martyr was adamant that the fathers of the Old Covenant had the same Spirit and the same Law written on their hearts. Zanchi says:
… the law was not written in their hearts, but remained written onely in tables and therfore did not chaunge men. But the gospell is written by the Holie ghost in the hearts of the elect and therefore it chaungeth and renueth them, because it is the instrument of the Holie ghost to sanctifie and to save us. (De religione christiana fides, 13.VIII.)
I am not positing any sharp discontinuity between Calvin and Vermigli on the one hand and Zanchius on the other, but this emphasis on the role of the Spirit in the New Covenant by the latter does seem more Thomistic.