from the unknowable God. 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 re-absorption 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
