If we regard the main test of educational efficiency as being in its research product and not simply the promulgation of material already attained, then Nestorianism was not an educational success: and it seems that this should be the supreme test, for knowledge is progressive, and so the smallest contribution towards further progress must be of more real value than the most efficient teaching of results already achieved. Yet it would be difficult to over-estimate the importance of Nestorianism in preparing an oriental version of Hellenistic culture in the pre-Muslim world. Its main importance lies in its being preparatory to Islam which brought forward Arabic as a cosmopolitan medium for the interchange of thought and so enabled the Syriac material to be used in a wider and more fruitful field. Although Nestorius had been condemned, the Church was left with a problem. The objection was true that, if the Logos and the rational soul in Christ were fused together so that the rational soul or spirit lost itself in its source, the Logos dwelt in an animal body and the full humanity of Christ disappeared. The Nestorian view of a temporary “connection” was now condemned as heretical, but was it necessary to go to the other extreme of “fusion” which was the logical result of the Alexandrian teaching? The Church wished to be philosophically correct and yet to avoid the conclusions which might be drawn from either view in its extreme form. In fact philosophy ruthlessly pressed home was the danger of which the Church was most afraid, feeling in some dim realm of sub-consciousness that the deposit of faith did not quite fall into line with science, or at least with the science then in fashion; and the Church’s real enemies were the enthusiasts who were confident that doctrine and philosophy were both absolutely true. Nor have we, even in these days, altogether learned the lesson that both are still partial and progressive. Islam had to go through exactly the same experience in her day and came out of it with very similar results, that is to say both the Christian and Muslim churches finally chose the _via media_ adopting the philosophical statement of doctrine but condemning as heretical the logical conclusions which might be deduced. The Alexandrian school, elated perhaps at its victory over Nestorius, became rather intemperate in the statement of its views and pressed them home to an extreme conclusion. At once the warning prediction of the Nestorians was justified: the teaching of a “fusion” between the Logos and the rational soul in Christ entirely undermined his humanity. Another controversy ensued and in this, as in the former one, neither side suggested any doubt as to the psychology or metaphysics borrowed from the Aristotelian and neo-Platonic philosophies, that was throughout assumed as certain, the problem was to make Christian doctrine fit in with it. Now those who opposed the