But such schools of science, founded on such a ground as this, on the mere instinct of curiosity, had little chance of originality or vitality. All the great schools of the world, the elder Greek philosophy, the Alexandrian, the present Baconian school of physics, have had a deeper motive for their search, a far higher object which they hope to discover. But indeed, the Mussulmans did not so much wish to discover truth, as to cultivate their own intellects. For that purpose a sharp and subtle systematist, like Aristotle, was the very man whom they required; and from the destruction of Alexandria may date the rise of the Aristotelian philosophy. Translations of his works were made into Arabic, first, it is said, from Persian and Syriac translations; the former of which had been made during the sixth and seventh centuries, by the wreck of the Neoplatonist party, during their visit to the philosophic Chozroos. A century after, they filled Alexandria. After them Almansoor, Hairoun Alraschid, and their successors, who patronised the Nestorian Christians, obtained from them translations of the philosophic, medical, and astronomical Greek works; while the last of the Omniades, Abdalrahman, had introduced the same literary taste into Spain, where, in the thirteenth century, Averroës and Maimonides rivalled the fame of Avicenna, who had flourished at Bagdad a century before. But, as I have said already, these Arabs seem to have invented nothing; they only commented. And yet not only commented; for they preserved for us those works of whose real value they were so little aware. Averroës, in quality of commentator on Aristotle, became his rival in the minds of the mediæval schoolmen; Avicenna, in quality of commentator on Hippocrates and Galen, was for centuries the text-book of all European physicians; while Albatani and Aboul Wefa, as astronomers, commented on Ptolemy, not however without making a few important additions to his knowledge; for Aboul Wefa discovered a third inequality of the moon’s motion, in addition to the two mentioned by Ptolemy, which he did, according to Professor Whewell, in a truly philosophic manner—an apparently solitary instance, and one which, in its own day, had no effect; for the fact was forgotten, and rediscovered centuries after by Tycho Brahe. To Albatani, however, we owe two really valuable heirlooms. The one is the use of the sine, or half-chord of the double arc, instead of the chord of the arc itself, which had been employed by the Greek astronomers; the other, of even more practical benefit, was the introduction of the present decimal arithmetic, instead of the troublesome sexagesimal arithmetic of the Greeks. These ten digits, however, seem, says Professor Whewell, by the confession of the Arabians themselves, to be of Indian origin, and thus form no exception to the sterility of the Arabian genius in scientific inventions. Nevertheless