A thorough and systematic advance of this sort was made by the orthodox Christologians of the fifth century. The campaign was fought and won then. It has, however, to be fought anew in each generation and in the experience of individual thinkers. Monophysitism is commonly regarded as a vagary of oriental thought, killed once and for all by a church council in the fifth century. That is a superficial view. Monophysitism is a hydra growth, and no Hercules can be found to exterminate it. It reappears in each succeeding age, in West as well as East. The structure of the human intellect is such that, whenever men begin to investigate the being of Christ, the tendency to regard Him as one-natured is present. The church of the fifth century exposed that doctrine; it was beyond her power to kill it. REASONS FOR THE PREVALENCE OF MONOPHYSITISM Monophysitism is in our midst undetected to-day. It is not hard to account for its prevalence. The clergy are for the most part unable to expound Christology, and the laity are impatient of exposition. Anything savouring of precise theology is at a discount. So pulpit and pew conspire to foster the growth of the tares. The "Athanasian" creed is in disrepute, and its statement of dogmatic Christology is involved in the discredit attaching to the damnatory clauses. The clergy are perhaps rather glad to leave the subject alone. They know it is a difficult subject, and they are afraid of burning their fingers. The laity rarely hear any reference to the two natures of Christ. If they do, they are not interested; they do not think that the question makes any difference to faith or practice. The whole extent of the Christological knowledge possessed by the average churchman is comprised in the formula, "Christ is God and man." He cannot apply the formula nor reconcile it with common sense. He occasionally hears from the pulpit the phrase "God-man"; but it is a mere phrase to him; it is not translated for him into a language that he can understand. So he registers the doctrine mentally as an impenetrable mystery and gives it no further attention, or perhaps turns away in disgust from the system whose central figure is so unintelligibly presented by its authorised exponents. The bare statement that Christ is God and man, though true, is not adequate. It carries no conviction to thinking minds to-day. The full definition of the council of Chalcedon should be published broadcast, and so studied by theologians in the light of modern psychology that they can present it as a reasonable dogma, intelligible to-day and touching modern life.