Church a part of the Roman Empire, that the acceptance of Christianity was regarded as a sign of subserviency to the latter. That fact is not without its significance in trying to realise conditions in Arabia in the time of Muhammad. It helps to explain the readiness with which even Christian Arabs accepted an independent Arabian prophet. It also no doubt played a part in forming Muhammad's ideas of what religion was. If we sometimes feel ourselves brought up with a shock against the fact that Islam is apparently incurably political, is, as we say, not only a religion but a state, we must remember that that was what Muhammad saw in Christianity, and also what he gathered from the Old Testament.

From the beginning of the fourth century the Church was troubled by doctrinal disputes. The Arian controversy was already raging when Constantine became sole emperor. One of his first acts was to summon the Council of Nicæa for the purpose of pacifying and reuniting the Church. Under the influence of the profound intellect and strong personality of Athanasius it resulted in the proclamation of the Homoousion. Some have deplored that the faith of the Church was thus wedded to philosophy, and that the way was opened to the intellectual speculation which transformed the simple gospel of divine love into a dogmatic system which appealed to the mind rather than to the heart. But the intellectual interpretation and justification of its faith is a task which the Church can never avoid. Intellectual speculation had very early begun to

lay hold upon Christian beliefs, and to fit them into varying systems, sometimes by the exercise of considerable violence. The alternative for the Church was not that of expressing its faith in terms of the prevailing philosophy or refraining from doing so. It was that between finding an adequate expression or being content with inadequate ones. The proclamation of the Homoousion at Nicæca was certainly a great victory for Monotheism and sane thinking. The growing worship of Christ as a Divine Being was at once justified and robbed of its idolatrous character by defining the Christ who was worshipped to be the Son of God, of one substance with the Father. In the language of philosophy it was the equivalent of the religious dictum of Paul that God was in Christ reconciling the world to Himself.¹

The decision of Nicæa did not settle the question. A period of acute controversy followed. Other questions also pressed for solution. The Holy Spirit was readily admitted to be likewise of one substance with the Father. But what was the relation between the three Persons? The worship of three separate divine entities being inadmissible, what distinctions in the Godhead did the facts of Christ and the Holy Spirit imply? That was the form in which the problem of reaching an adequate conception of God presented itself to the Christian thinkers of the fourth century. On the other hand, if God was incarnate in Jesus Christ, what was the relation between the divine and the human in Him?