Considering the time, place, and circumstances in which it arose, and having regard to the character of the man who bore a chief part in its development, we cannot hesitate, I think, to assert that it is largely a product of Greek speculation. Ma‘rúf al-Karkhí, Abú Sulaymán al-Dárání, and Dhu ’l-Nún al-Miṣrí all three lived and died in the period (786-861 A.D.) which begins with the accession of Hárún al-Rashíd and is terminated by the death of Mutawakkil. During these seventy-five years the stream of Hellenic culture flowed unceasingly into the Moslem world. Innumerable works of Greek philosophers, physicians, and scientists were translated and eagerly studied. Thus the Greeks became the teachers of the Arabs, and the wisdom of ancient Greece formed, as has been shown in a preceding chapter, the basis of Muḥammadan science and philosophy. The results are visible in the Mu‘tazilite rationalism as well as in the system of the _Ikhwánu ’l-Ṣafá_. But it was not through literature alone that the Moslems were imbued with Hellenism. In ‘Iráq, Syria, and Egypt they found themselves on its native soil, which yielded, we may be sure, a plentiful harvest of ideas--Neo-platonic, Gnostical, Christian, mystical, pantheistic, and what not? In Mesopotamia, the heart of the ‘Abbásid Empire, dwelt a strange people, who were really Syrian heathens, but who towards the beginning of the ninth century assumed the name of Ṣábians in order to protect themselves from the persecution with which they were threatened by the Caliph Ma’mún. At this time, indeed, many of them accepted Islam or Christianity, but the majority clung to their old pagan beliefs, while the educated class continued to profess a religious philosophy which, as it is described by Shahrastání and other Muḥammadan writers, is simply the Neo-platonism of Proclus and Iamblichus. To return to Dhu ’l-Nún, it is incredible that a mystic and natural philosopher living in the first half of the ninth century in Egypt should have derived his doctrine directly from India. There may be Indian elements in Neo-platonism and Gnosticism, but this possibility does not affect my contention that the immediate source of the Ṣúfí theosophy is to be sought in Greek and Syrian speculation. To define its origin more narrowly is not, I think, practicable in the present state of our knowledge. Merx, however, would trace it to Dionysius, the Pseudo-Areopagite, or rather to his master, a certain "Hierotheus," whom Frothingham has identified with the Syrian mystic, Stephen bar Sudaili (_circa_ 500 A.D.). Dionysius was of course a Christian Neo-platonist. His works certainly laid the foundations of mediæval mysticism in Europe, and they were also popular in the East at the time when Ṣúfiism arose. [Sidenote: Ṣúfiism composed of many different elements.]