As far as we can find out there have been esoteric schools since the time of Abraham; and many of them may be called Sufi schools. The Sufi schools of Arabia absorbed Arabic culture and were largely metaphysical; the Sufi schools of Persia developed more the literary aspect, and the Sufi schools of India developed the meditative faculty; but the truth and the ideal have remained the same, as the central theme of Sufism, in all these schools. Several exist even now, and it would not be an exaggeration to say that there are millions of souls, the followers of different religions, who are benefited by the wisdom of these schools.