Moslem scholars divided the medieval peoples into two classes—those that cultivated science, and those that did not. In the first class they named the Hindus, Persians, Babylonians, Jews, Greeks, Egyptians, and Arabs. These, in their view, were the elite of the world; the others, of whom the Chinese and the Turks were the best, resembled animals rather than men.72 The judgment sinned chiefly against the Chinese.
The Moslems continued, in this period, their unchallenged ascendancy in science. In mathematics the most signal advances were made in Morocco and Azerbaijan; we see here again the range of Islamic civilization. In 1229 Hasan al-Marraqushi (i.e., of Marraqesh) published tables of sines for each degree, and tables of versed sines, arc sines, and arc cotangents. A generation later Nasir ud-Din al-Tusi (i.e., of Tus) issued the first treatise in which trigonometry was considered as an independent science rather than an appendage to astronomy; this Kitab shakl al-qatta remained without a rival in its field until the De Triangulis of Regiomontanus two centuries later. Perhaps Chinese trigonometry, which appears in the second half of the thirteenth century, was of Arabic origin.73
The outstanding work of physical science in this age was the Kitab mizan al-hikmah, or Book of the Balance of Wisdom, written about 1122 by a Greek slave from Asia Minor, Abu’l Fath al-Khuzini. It gave a history of physics, formulated the laws of the lever, compiled tables of specific gravity for many liquids and solids, and proposed a theory of gravitation as a universal force drawing all things towards the center of the earth.74 Water wheels, known to the Greeks and Romans, were improved by the Moslems; the Crusaders saw such wheels raising water from the Orontes, and introduced them into Germany.75 Alchemists flourished; they knew, said al-Latif, “300 ways of making dupes.”76 One alchemist drew from Nur-ud-din a substantial loan for alchemical research, and disappeared; a wit, apparently unreproved, published a list of fools in which Nurud-din’s name led all the rest; and offered, if the alchemist would return, to substitute his name for that of the Sultan.77
In 1081 Ibrahim al-Sahdi of Valencia constructed the oldest known celestial globe, a brass sphere 209 millimeters (81.5 inches) in diameter; upon its surface, in forty-seven constellations, were engraved 1015 stars in their respective magnitudes.78 The Giralda of Seville (1190) was an observatory as well as a minaret; there Jabir ibn Aflah made the observations for his Islah al-majisti, or Correction of the Almagest (1240). The same reaction against Ptolemaic astronomy marked the works of Abu Ishaq al-Bitruji (Alpetragius) of Cordova, who paved the way for Copernicus by destructively criticizing the theory of epicycles and eccentrics through which Ptolemy had sought to explain the paths and motions of the stars.
The age produced two geographers of universal medieval renown. Abu Abdallah Muhammad al-Idrisi was born at Ceuta (1100), studied at Cordova, and wrote in Palermo, at the behest of King Roger II of Sicily, his Kitab al-Rujari (Roger’s Book). It divided the earth into seven climatic zones, and each zone into ten parts; each of the seventy parts was illustrated by a detailed map; these maps were the crowning achievement of medieval cartography, unprecedented in fullness, accuracy, and scope. Al-Idrisi, like most Moslem scientists, took for granted the sphericity of the earth. Rivaling him for the honor of being the greatest medieval geographer was Abu Abdallah Yaqut (1179–1229). Born a Greek in Asia Minor, he was captured in war and enslaved; but the Baghdad merchant who bought him gave him a good education, and then freed him. He traveled much, first as a merchant, then as a geographer fascinated by places and their diverse populations, dress, and ways. He rejoiced to find ten libraries at Merv, one containing 12,000 volumes; the discriminating curators allowed him to take as many as 200 volumes at a time to his room; those who have loved books as the lifeblood of great men will sense the dusty joy he felt in these treasuries of the mind. He moved on to Khiva and Balkh; there the Mongols almost caught him in their murderous advance; he fled, naked but clutching his manuscripts, across Persia to Mosul. While buttering the bread of poverty as a copyist, he completed his Mu’jam al-Buldan (1228)—a vast geographical encyclopedia which summed up nearly all medieval knowledge of the globe. Yaqut included almost everything—astronomy, physics, archaeology, ethnography, history, giving the co-ordinates of the cities and the lives and works of their famous men. Seldom has any man so loved the earth.
Botany, almost forgotten since Theophrastus, revived with the Moslems of this age. Al-Idrisi wrote a herbal, but stressed the botanical rather than merely the medicinal interest of 360 plants. Abu’l Abbas of Seville (1216) earned the surname of al-Nabati, the Botanist, by his studies of plant life from the Atlantic to the Red Sea. Abu Muhammad ibn Baitar of Malaga (1190–1248) gathered all Islamic botany into a vast work of extraordinary erudition, which remained the standard botanical authority till the sixteenth century, and marked him as the greatest botanist and pharmacist of the Middle Ages.79 Ibn al-Awan of Seville (1190) won a like pre-eminence in agronomy; his Kitab al-Falaha (Book of the Peasant) analyzed soils and manures, described the cultivation of 585 plants and fifty fruit trees, explained methods of grafting, and discussed the symptoms and cures of plant diseases. This was the most complete treatment of agricultural science in the whole medieval period.80
In this as in the preceding age the Moslems produced the leading physicians of Asia, Africa, and Europe. They excelled especially in ophthalmology, perhaps because eye diseases were so prevalent in the Near East; there, as elsewhere, medicine was paid most to cure, least to prevent. Operations for cataract were numerous. Khalifah ibn-abi’l-Mahasin of Aleppo (1256) was so confident of his skill that he operated for cataract on a one-eyed man.81 Ibn Baitar’s Kitab al-Jami made medicinal-botanical history; it listed 1400 plants, foods, and drugs, 300 of them new; analyzed their chemical constitution and healing power; and added acute observations on their use in therapy. But the greatest name in this acme of Moslem medicine is Abu Marwan ibn Zuhr (1091–1162) of Seville, known to the European medical world as Avenzoar. He was the third in six generations of famous physicians, all of one family line, and each at the top of his profession. His Kitab al-Tasir, or Book of Simplification on Therapeutics and Diet, was written at the request of his friend Averroës, who (himself the greatest philosopher of the age) considered him the greatest physician since Galen. Ibn Zuhr’s forte was clinical description; he left classical analyses of mediastinal tumors, pericarditis, intestinal tuberculosis, and pharyngeal paralysis.82 Translations of the Tasir into Hebrew and Latin deeply influenced European medicine.
Islam led the world also in the equipment and competence of its hospitals. One founded by Nur-ud-din at Damascus in 1160 gave free treatment and drugs during three centuries; for 267 years, we are told, its fires were never extinguished.83 Ibn Jubayr, coming to Baghdad in 1184, marveled at the great Bimaristan Adadi, a hospital rising like some royal palace along the banks of the Tigris; here food and drugs were given to the patients without charge.84 In Cairo, in 1285, Sultan Qalaun began the Maristan al-Mansur, the greatest hospital of the Middle Ages. Within a spacious quadrangular enclosure four buildings rose around a courtyard adorned with arcades and cooled with fountains and brooks. There were separate wards for diverse diseases and for convalescents; laboratories, a dispensary, out-patient clinics, diet kitchens, baths, a library, a chapel, a lecture hall, and particularly pleasant accommodations for the insane. Treatment was given gratis to men and women, rich and poor, slave and free; and a sum of money was disbursed to each convalescent on his departure, so that he need not at once return to work. The sleepless were provided with soft music, professional storytellers, and perhaps books of history.85 Asylums for the care of the insane existed in all the major cities of Islam.