By the fifth century Arian doctrine had been completely eliminated from the state church and Alexandrian philosophy which had been the chief means of bringing about this result, was dominant, although there are indications that it was viewed with suspicion in some quarters. Amongst the controversies which took place in the post-Nicene age the most prominent are those which concerned the person of the incarnate Christ, and these are largely questions of psychology. It was generally admitted that man has a _psyche_ or animal soul which he shares with the rest of the sentient creatures, and in addition to this a spirit or rational soul which, under the influence of the neo-Platonists or of Alexander of Aphrodisias, was regarded as an emanation from the creative spirit, the Logos or “Agent Intellect,” a belief which Christian theologians supported by the statement in Genesis that God breathed into man the breath of life and so man became a living soul. In fact St. Paul had already distinguished between the two elements, the animal soul and the immortal spirit, in accordance with the psychology which had been developed in his time. But Christian theology supposed that in Christ was also present the eternal Logos which had been the creative Spirit and of which the spirit or rational soul was itself an emanation. What, therefore, would be the relation between the Logos and its own emanation when they came together in the same person? If the Alexandrian philosophy and the Christian religion were both true the problem was capable of reasonable solution: if its only answer was a manifest absurdity then either the psychology or Christianity was in error, and then, as always, it was assumed that contemporary science was sure and religion had to be tested by its standard. To this particular problem two solutions were proposed. The one, especially maintained at Alexandria, was that the Logos and the rational soul or spirit, being in the relation of source and emanation, necessarily fused together when simultaneously present in the same body, the point being of course that the Logos was the agent of creation, the True God not acting therein as it was an activity in time, but through the intermediary of the Logos, whilst the animal soul dispersed through creation was ultimately derived from the Logos, but the spirit was directly proceeding from it, all of which represents the philosophical theory formulated by Alexander of Aphrodisias and the neo-Platonists and then accepted as unassailable. The other solution, which found its chief advocates at Antioch, laid stress on the completeness of the humanity of Christ so that the body, animal soul, and spirit were necessarily complete in the humanity and the Logos dwelt in the human frame without subtracting the spirit which was one of the essentials of humanity, and so there could have been no fusion because this would have implied the return of the spirit to its source and consequently