The opposite doctrine to the one which we have been considering, that of the divine right of kings, comes to the surface sporadically in the _Code_ of Justinian, but it is not definitely formulated until we reach the time of Gregory the Great in the sixth century. He develops the new doctrine fully in his _Pastoral Rules_ and in his treatise on the book of Job, as the Carlyles have shown, and it is from him that it passed down into the Middle Ages and into later times. The Carlyles trace its development to three causes: (1) the need of checking the anarchical tendency of the primitive Church; (2) the favored position which the Church had under the protection of the Emperor after the conversion of Constantine; and (3) the influence of the Old Testament conception of the position of the King of Israel. The teachings of the Old Testament were reinforced by those of the New Testament. In the _Epistle to the Romans_ we read, for instance: “Let every soul be subject unto the higher powers. For there is no power but of God; the powers that be are ordained of God,” and elsewhere: “Submit yourselves to every ordinance of man for the Lord’s sake; whether it be to the king, as supreme; or unto governors, as unto them that are sent by him for the punishment of evil doers, and for the praise of them that do well,” I. _Peter_, ii. 13-14. This second explanation of the source of authority in the state, which the phrases used by the Roman jurists occasionally suggest, was accepted by the early Church and transmitted by it through the Middle Ages to modern times. The king was answerable only to God. To resist him was impious.