Marianos, another relates the manner in which he studied chemistry, and a third explains the enigmatical allusions employed by his teachers. Long before this medical and scientific studies had passed over to Persia, but Alexandria retained its reputation as the chief centre of such work throughout the 'Umayyad period.
Towards the end of the 'Umayyad age the influence of Hellenistic thought begins to appear in the nature of criticism upon accepted views of Muslim theology. As in jurisprudence, we have no ground for supposing that Muslims at this stage were directly acquainted with Greek material, but general ideas were obtained by intercourse with those who had been long under Hellenistic influences, and especially by intercourse with Christians amongst whom the premises of psychology, metaphysics, and logic had encroached very largely upon the field of theology by the nature of the subjects debated in the Arian, Nestorian, and Monophysite controversies which turned mainly upon psychological and metaphysical problems. The ideas with which the Muslims were brought into contact suggested difficulties in their own theology, as yet only partially formulated, and in religious theories which had taken form in a community entirely ignorant of philosophy. Some of the older fashioned believers met these questions with a plain negative, simply refusing to admit that there was a difficulty or any question for consideration: reason ('aql), they said, could not be applied to the revela-
