“Vos” was his name. Geerhardus Vos.
A friend supplied me this “foxy” quote as an encouragement in clarifying the issues surrounding NL2K (a modern construal of Natural Law + 2 Kingdoms):
 From this, however, it does not necessarily follow, that the visible church is the only outward expression of the invisible kingdom. Undoubtedly the kingship of God, as his recognized and applied supremacy, is intended to pervade and control the whole of human life in all its forms of existence. This the parable of the leaven plainly teaches. These various forms of human life have each their own sphere in which they work and embody themselves. There is a sphere of science, a sphere of art, a sphere of the family and of the state, a sphere of commerce and industry. Whenever one of these spheres comes  under the controlling influence of the principle of the divine supremacy and glory, and this outwardly reveals itself, there we can truly say that the Kingdom of God has become manifest.
But “the Fox” has just begun. Read on:
 And what is true of the relation between church and state, may also be applied to the relation between the visible church and the various other branches into which the organic life of humanity divides itself. It is entirely in accordance with the spirit of Jesus’ teaching to subsume these under the kingdom of God and to co-ordinate them with the visible church as true manifestations of this kingdom, in so far as the divine sovereignty and glory have become in them the controlling principle. But it must always be remembered, that the latter can only happen, when all these, no less than the visible church, stand in living contact with the forces of regeneration supernaturally introduced into the  world by the Spirit of God. While it is proper to separate between the visible church and such things as the Christian state, Christian art, Christian science, etc., these things, if they truly belong to the kingdom of God, grow up out of the regenerated life of the invisible church.
For your files, the complete bibliographical reference is: Geerhardus Vos, The Teaching of Jesus Concerning the Kingdom of God and the Church (Nutley, NJ: Presbyterian and Reformed Publishing Co., 1972 [repr.]), 87-89.
*Thanks to Nelson Kloosterman for this information from Geerhardus Vos.