As time went on, however, it became clear that Alexander must intervene. Arius was now the enthusiastic advocate of theories which aimed at the very root of the Christian religion, inasmuch as they denied the essential Godhead of Christ. It was no longer a case of a daring thinker tentatively hinting at doctrines which were hardly in accord with established belief. Arius was devoting himself just to those points where he was at variance with his fellows, was insisting upon them in season and out of season, and was treating them as the very essence of Christianity. He had issued his challenge; Alexander was compelled to take it up. The Patriarch sent for him privately. He wished either to convince him of his error or to induce him to be silent. But the interview was of no avail. Arius simply preached the more. Alexander then summoned a meeting of the clergy of Alexandria, and brought forward for discussion the accepted doctrine of the Holy Trinity which Arius had challenged. Arius and his sympathisers were present and the controversy was so prolonged that the meeting had to be adjourned; when it reassembled, the Patriarch endeavoured to bring the debate to a close by restating the doctrine of the Holy Trinity in a form which he hoped would be unanimously approved. But this merely precipitated an open rupture. For Arius immediately rose and denounced Alexander for falling into the heresy of Sabellianism and reducing the Second Person in the Trinity to a mere manifestation of the First. It is to be remembered that the doctrine of the Holy Trinity—difficult as it is even now, after centuries of discussion, to state in terms that are free from all equivocation—must have been far more difficult to state then, before the Arian controversy had, so to speak, crystallised the exact meaning of the terms employed. It seems quite clear, moreover, from what subsequently took place, that Alexander was no match for Arius in dialectical subtlety and that Arius found it easy to twist his chief’s unskilful arguments and expressions into bearing an interpretation which Alexander had not intended. At any rate the inevitable result of the conference was that both sides parted in anger, and Arius continued as before to preach the doctrine that the Son of God was a creature. For this was the leading tenet of Arianism and the basis of the whole heresy, that the Son of God was a creature, the first of all creatures, it is true, and created before the angels and archangels, ineffably superior to all other creatures, yet still a creature and, as such, ineffably inferior to the Creator, God the Father Himself.