The same truth holds of the other Christological systems. A different metaphysical idea lies at the root of each. Nestorian, monophysite, catholic, these three were the main types of Christologian in the fifth century. Each studied Christ's life. After studying it, the Nestorian said of Him, "There are two persons here." "Not so," said the monophysite, "I see but one incarnate nature of God the Word." The catholic replied, "You are both wrong; there is one person in two natures." All three types deserve close study. The thinkers were devout and sincere, and, for the most part, able men. There is no question here of superficial uninformed thought, nor of moral obliquity. The disagreement was due not to their vision but to their view point, not to the object of their thought or the process of their thinking, but to their different presuppositions and starting points. Presented in this way the monophysite and other Christological controversies of the fifth and sixth centuries become phases of the cosmic problem. They thus regain the dignity which is theirs by right, and which they lose in the ordinary church histories. The heat of passion they aroused becomes intelligible. It was no battle about words. The stakes were high. The controversialists championed far-reaching principles with a decisive influence on the course of thought and conduct. Unfriendly critics usually portray the Christologians as narrow-minded and audacious. So, no doubt, they were, but they were not wrong-headed. If the matters in dispute between theist, deist, and pantheist are trivialities, then and then only can we regard the enterprise of the Christologians as chimerical and their achievements as futile. The different formulae represented attitudes of mind fundamentally opposed. No peace between catholic and monophysite was possible. They had conflicting conceptions of ultimate truth. DEPENDENCE OF CHRISTOLOGY ON PHILOSOPHY We mentioned above the two other chief Christological systems, the Nestorian and the catholic. No analysis of monophysitism which omitted a reference to these systems would be complete. They were three nearly contemporary attempts to solve the same problem. The comparison is of special interest when, as here, fundamental principles are under examination. It demonstrates the closeness of the connection between the Christological and the cosmic problems. In each of the three cases we find that a school of philosophy corresponds to the school of theology, and that the philosopher's dominant idea about the cosmos decided the theologian's interpretation of Christ.