CHAPTER IV.
THE RESTORATION OF SCIENCE IN THE SOUTH.
By the influence of the Nestorians and Jews, the Arabians are turned to the cultivation of Science .-- They modify their views as to the destiny of man, and obtain true conceptions respecting the structure of the world .-- They ascertain the size of the earth, and determine its shape .-- Their khalifs collect great libraries, patronize every department of science and literature, establish astronomical observatories .-- They develop the mathematical sciences, invent algebra, and improve geometry and trigonometry .-- They collect and translate the old Greek mathematical and astronomical works, and adopt the inductive method of Aristotle .-- They establish many colleges, and, with the aid of the Nestorians, organize a public-school system .-- They introduce the Arabic numerals and arithmetic, and catalogue and give names to the stars .-- They lay the foundation of modern astronomy, chemistry, and physics, and introduce great improvements in agriculture and manufactures.
"IN the course of my long life," said the Khalif Ali, "I have often observed that men are more like the times they live in than they are like their fathers." This profoundly philosophical remark of the son-in-law of Mohammed is strictly true; for, though the personal, the bodily lineaments of a man may indicate his parentage, the constitution of his mind, and therefore the direction of his thoughts, is determined by the environment in which he lives.
When Amrou, the lieutenant of the Khalif Omar, conquered Egypt, and annexed it to the Saracenic Empire, he found in Alexandria a Greek grammarian, John surnamed Philoponus, or the Labor-lover.

Presuming on the friendship which had arisen between them, the Greek solicited as a gift the remnant of the great library--a remnant which war and time and bigotry had spared.

Amrou, therefore, sent to the khalif to ascertain his pleasure.

"If," replied the khalif, "the books agree with the Koran, the Word of God, they are useless, and need not be preserved; if they disagree with it, they are pernicious.

Let them be destroyed." Accordingly, they were distributed among the baths of Alexandria, and it is said that six months were barely sufficient to consume them.
Although the fact has been denied, there can be little doubt that Omar gave this order.