were educated; though in comparison with his predecessor Al Farabi, who leant to Platonic mysticism, he is a rationalistic Aristotelian, [1140] with a strong leaning to pantheism. Of him an Arabic historian writes that in his old age he attached himself to the court of the heretical Ala-ud-Dawla at Ispahan, in order that he might freely write his own heretical works. [1141] After Al Gazzali (d. 1111), who attacked both Avicenna [1142] and Al Farabi somewhat in the spirit of Cicero's skeptical Cotta attacking the Stoics and the Epicureans, [1143] there seems to have been a further development of skepticism, the skeptical defence of the faith having the same unsettling tendency in his as in later hands. Ibn Khaldun seems to denounce in the name of faith his mixture of pietism and philosophy; and Makrisi speaks of his doctrines as working great harm to religion [1144] among the Moslems. But the socio-political conditions were too unpropitious to permit of any continuous advance on rational lines. Ere long an uncritical orthodoxy prevailed in the Eastern schools, and it is in Moorish Spain that we are to look for the last efforts of Arab philosophy. The course of culture-evolution there broadly corresponds with that of the Saracen civilization in the East. In Spain the Moors came into contact with the Roman imperial polity, and at the same time with the different culture elements of Judaism and Christianity. To both of these faiths they gave complete toleration, thus strengthening their own in a way that no other policy could have availed to do. Whatever was left of Græco-Roman art, handicraft, and science, saving the arts of portraiture, they encouraged; and whatever of agricultural science remained from Carthaginian times they zealously adopted and improved. Like their fellow-Moslems in the East, they further learned all the science that the preserved literature of Greece could give them. The result was that under energetic and enlightened khalifs the Moorish civilization became the centre of light and knowledge as well as of material prosperity for medieval Europe. Whatever of science the world possessed was to be found in their schools; and thither in the tenth, eleventh, and twelfth centuries flocked students from the Christian States of western and northern Europe. It was in whole or in part from Saracen hands that the modern world received astronomy, chemistry, mathematics, medicine, botany, jurisprudence, and philosophy. They were, in fact, the revivers of civilization after the age of barbarian Christianity. [1145] And while the preservation of Greek science, lost from the hands of Christendom, would have been a notable service enough, the Arabs did much more. Alhazen (d. 1038) is said to have done the most original work in optics before Newton, [1146] and in the same century Arab medicine and chemistry made original advances. [1147]