Comparing this with the teaching of al-Kindi and al-Farabi it is clear that it is based upon the same material, but it is in the hands of those who have made it a religion, and this religion has entirely broken away from the orthodox doctrine of the Qur´an. In al-Farabi this breach is not conscious, although really quite complete; in his successors we see a full realization of the cleavage. Comparing it with Sufism the superficial resemblances are very close, the more so as Sufism borrows a great deal of philosophical, i.e., neo-Platonic terminology, but in fact there is an essential divergence: the Epistles of the brethren represent the emancipation of the soul from matter as the aim of life, and the final result is reabsorption in the Universal Soul, but they represent this emancipation as due to an intellectual force, so that the soul’s salvation lies in wisdom and knowledge; it is a cult of intellect. But Sufism is spiritual in another sense: it has the same aim in view, but it regards the means as wisdom in the sense of religious truth as found by the devout soul in piety, not as the wisdom obtained by intellectual learning. We seem, however, justified in saying that Sufism is the heir of the philosophical teaching of al-Farabi and the Brethren of Purity, at least in Asia. After the first quarter of the fifth century philosophical teaching seems to have disappeared altogether in Asia, but this is only apparent. In substance it remains in Sufism, and we may say that the essential change lies in the new meaning given to “wisdom,” which ceases to signify scientific facts and speculations acquired intellectually, and is taken to mean a supra-intellectual knowledge of God. This, perhaps, represents the Indian contribution working upon elements of Hellenistic origin. The doctrines of the _Brethren of Purity_ were introduced to the West by a Spanish doctor, Muslim b. Muhammad Abu l-Qasim al-Majriti al-Andalusi (d. 395-6), and were largely influential in producing the _falasifa_ of Spain, who ultimately exercised so great an influence on mediæval Latin scholasticism. Before leaving this particular section of our subject it will be well to note that all these sects and groups we have mentioned after al-Farabi, from the sect founded by Abdullah b. Maymun to the Brethren of Purity, agreed in treating philosophy, at least in so far as it had any bearing on theological topics, as esoteric, and not to be disclosed to any save the elect. This general attitude will appear again, in a slightly different form, in the works of the Spanish philosophers, and to some extent recurs in all Islamic thought.