According to the Koran, the earth was a square plane, on the edges of which rested the heavenly vault, divided into seven stories, in the topmost of which dwelt god in his omnipotence. This theory, however, was quickly given up by the learned Saracens, Al-Mamun declaring it to be unscientific, and asserting that the earth was globular, with a circumference of about 24,000 miles, which was not far wrong. In 661 the Khalif Moawyah encouraged this new teaching, and ordered the writings of the Greek philosophers to be translated into Arabic. In 753 the Khalif Almansar recommended the study of astronomy, medicine, and law at Bagdad; and his grandson, Haroum-al-Raschid, ordered that every mosque should have a school attached to it, and established a large library at Bagdad for the use of learned men. The sciences of chemistry and geometry were revived, and algebra invented by the Saracens. At Cairo the Fatimist Library became the wonder of the world; and the great library of the Spanish Khalifs had 600,000 vols., its catalogue alone occupying 44 vols. Gibbon tells us that they “diffused the taste and the rewards of science from Samarcand and Bokhara to Fez and Cordova, and that the vizier of a sultan consecrated a sum of two hundred thousand pieces of gold to the foundation of a college at Bagdad, which he endowed with an annual revenue of fifteen thousand dinars.” The first medical college in Europe was founded by the Saracens at Salerno in Italy, and the first astronomical observatory was erected by them at Seville in Spain. The streets in Spain were lighted, baths were erected, and total abstinence universally practised. Thus we see that, while the power of the Church was gradually steeping central Europe in darkness, ignorance, and wretchedness, progress was on the march again in Western Asia, Africa, and Spain. During this period, however, there were not wanting in Europe bold men who attempted a revival of philosophy; but these were quickly suppressed by the Church. In A.D. 800 there appeared a man in Britain called John Erigena, who, having read Aristotle’s works, adopted his views and attempted to reconcile them with the Christian religion. There were also many Christian divines who had crossed the Mediterranean to study philosophy secretly from Mohammedan doctors. Erigena declared that every living thing evolved from something that had previously lived; that each particular life-form was but a part of general existence or mundane soul; and that all life must be eventually re-absorbed in deity. The Church became infuriated and alarmed at this heretical barbarian, who taught the pernicious doctrines of emanation and absorption, and steps were immediately taken to suppress him.