Beruni brings into striking prominence the harmony which exists between the Pythagorean-Platonic philosophy, Indian wisdom, and many of the Sufi views. No less striking is his recognition of the superiority of Greek Science, when compared with the attempts and performances of the Arabs and the Indians. ‘India’, he says, ‘not to mention Arabia, has produced no Socrates: there no logical method has expelled phantasy from science’. But yet he is ready to do justice to individual Indians, and he quotes with approval the following, as the teaching of the adherents of Aryabhata: “It is enough for us to know that which is lighted up by the sun’s rays. Whatever lies beyond, though it should be of immeasurable extent, we cannot make use of; for what the sunbeam does not reach, the senses do not perceive, and what the senses do not perceive, we cannot know”. From this we may gather what Beruni’s philosophy was: Only sense-perceptions, knit together by a logical intelligence, yield sure knowledge; and for the uses of life we need a practical philosophy, which enables us to distinguish friend from foe. He doubtless did not himself imagine that he had said all that could be said on the subject. 10. From the school of Ibn Sina, we have had more names handed down, than we have had writings preserved. Djuzdjani annexes to his Autobiography an account of the life of the master. And, farther, we have one or two short metaphysical treatises by Abu-l-Hasan Behmenyar ibn al-Marzuban, which are nearly in complete agreement with the system of his teacher. But Matter appears to lose somewhat of its substantiality: as Possibility of Existence it becomes a relation of thought. According to Behmenyar, God is the pure, uncaused Unity of Necessary Existence,—not the living, all-producing Creator. True enough, He is the cause of the world, but the effect is given necessarily and synchronously with the cause; otherwise the cause would not be perfect, being capable of change. Essentially, though not in point of time, the existence of God precedes that of the world. Three predicates thus pertain to the highest existence, viz., that it is (1) essentially first, (2) self-sufficing, and (3) necessary. In other words God’s essential nature is the Necessity of his Existence. All that can possibly be,—owes its existence to this Absolutely Necessary Being. Now that is quite in harmony with the doctrines of Ibn Sina; and the same is the case with the disciple’s scheme of the world and his doctrine of Souls. Whatever has once attained to full reality,—the various Sphere-Spirits according to their kind, Primeval Matter, and the individually different Souls of Men,—all lasts for ever. Nothing that is completely real can pass away, inasmuch as the completely real has nothing to do with mere possibility.