(Ἰωάννης ὁ Φιλόπονος), or JOANNES GRAMMA'TICUS (ὁ Γραμματικός), an Alexandrine scholar of great renown, which he deserved but little on account of his extreme dullness and want of good sense, was called Φιλόπονος because he was one of the most laborious and studious men of his age. He lived in the seventh century of our era; one of his writings, Physica, is dated the 10th of May, A. D. 617. He calls himself γραμματικός, undonbtedly because he taught grammar in his native town, Alexandria, and would in earlier times have been called rhetor. He was a disciple of the philosopher Ammonius. Although his renown is more based upon the number of his learned productions, and the estimation in which they were held by his contemporaries, than upon the intrinsic value of those works, he is yet so strangely connected with one of the most important events of his time, though only through subsequent tradition, that his name is sure to be handed down to future generations. We allude to the capture of Alexandria by Amru in A. D. 639, and the pretended conflagration of the famous Alexandrine library. It is in the first instance said that Philoponus adopted the Mohammedan religion on the city being taken by Amru, whence he may justly be called the last of the pure Alexandrian grammarians. Upon this, so the story goes, he requested Amru to grant him the possession of the celebrated library of Alexandria. Having informed the absent khalif Omar of the philosopher's wishes, Amru received for answer that if the books were in conformity with the Koran, they were useless, and if they did not agree with it, they were to be condemned, and ought in both cases to be destroyed. Thus the library was burnt. We now know, however, that this story is most likely only an invention of Abul-faraj, the great Arabic writer of the 13th century, who was however a Christian, and who, at any rate, was the first who ever mentioned such a thing as the burning of the Alexandrine library. We consequently dismiss the matter, referring the reader to the 51st chapter of Gibbon's "Decline and Fall." It is extremely doubtful that Philoponus became a Mohammedan. His favourite authors were Plato and Aristotle, whence his tendency to heresy, and he was either the founder or one of the first and principal promoters of the sect of the Tritheists, which was condemned by the council of Constantinople of 681. The time of the death of Philoponus is not known.