by Will Durant
The scholars of Islam in this period strengthened the foundations of a distinguished literature by their labors in grammar, which gave the Arabic tongue logic and standards; by their dictionaries, which gathered the word wealth of that language into precision and order; by their anthologies, encyclopedias, and epitomes, which preserved much that was otherwise lost; and by their work in textual, literary, and historical criticism. We gratefully omit their names, and salute their achievement.
Those whom we remember best among the scholars are the historians, for to them we owe our knowledge of a civilization that without them would be as unknown to us as Pharaonic Egypt before Champollion. Muhammad ibn Ishaq (d. 767) wrote a classical Life of Mohammed; as revised and enlarged by Ibn Hisham (763) it is—barring the Koran—the oldest significant Arabic prose work that has reached us. Curious and tireless scholars composed biographical dictionaries of saints, or philosophers, or viziers, or jurists, or physicians, or calligraphers, or mandarins, or lovers, or scholars. Ibn Qutaiba (828–89) was one of many Moslems who attempted to write a history of the world; and unlike most historians he had the courage to set his own religion in that modest perspective which every nation or faith must bear in time’s immensity. Muhammad al-Nadim produced in 987 an Index of the Sciences (Fihrist al-’ulum), a bibliography of all books in Arabic, original or translated, on any branch of knowledge, with a biographical and critical notice of each author, including a list of his virtues and vices; we may estimate the wealth of Moslem literature in his time by noting that not one in a thousand of the volumes that he named is known to exist today.13
The Livy of Islam14 was Abu Jafar Muhammad al-Tabari (838–923). Like so many Moslem writers, he was a Persian, born in Tabaristan, south of the Caspian Sea. After several years spent as a poor wandering scholar in Arabia, Syria, and Egypt, he settled down as a jurist in Baghdad. For forty years he devoted himself to composing an enormous universal chronicle—Annals of the Apostles and Kings (Kitab akhbar al-Rusul wal-Muluk)—from the creation to 913. What survives fills fifteen large volumes; we are told that the original was ten times as long. Like Bossuet, al-Tabari saw the hand of God in every event, and filled his early chapters with pious nonsense: God “created men to test them”;15 God dropped upon the earth a house built of rubies for Adam’s dwelling, but when Adam sinned God drew it up again.16 Al-Tabari followed the Bible in giving the history of the Jews; accepted the Virgin Birth of Christ (Mary conceived Jesus because Gabriel blew into her sleeve),17 and ended Part One with Jesus’ ascension into heaven. Part Two is a far more creditable performance, and gives a sober, occasionally vivid, history of Sasanian Persia. The method is chronological, describing events year by year, and usually traditional—tracing the narratives through one or more chains of Hadith to an eyewitness or contemporary of the incident. The method has the virtue of stating sources carefully; but as al-Tabari makes no attempt to co-ordinate the diverse traditions into a sustained and united narrative his history remains a mountain of industry rather than a work of art.
Al-Masudi, al-Tabari’s greatest successor, ranked him as al-Masudi’s greatest predecessor. Abu-l-Hasan Ali al-Masudi, an Arab of Baghdad, traveled through Syria, Palestine, Arabia, Zanzibar, Persia, Central Asia, India, and Ceylon; he claims even to have reached the China Sea. He gathered his gleanings into a thirty-volume encyclopedia, which proved too long for even the spacious scholars of Islam; he published a compendium, also gigantic; finally (947)—perhaps realizing that his readers had less time to read than he had to write—he reduced his work to the form in which it survives, and gave it the fancy title, Meadows of Gold and Mines of Precious Stones. Al-Masudi surveyed omnivorously the geography, biology, history, customs, religion, science, philosophy, and literature of all lands from China to France; he was the Pliny as well as the Herodotus of the Moslem world. He did not compress his material to aridity, but wrote at times with a genial leisureliness that did not shun, now and then, an amusing tale. He was a bit skeptical in religion, but never forced his doubts upon his audience. In the last year of his life he summarized his views on science, history, and philosophy in a Book of Information, in which he suggested an evolution “from mineral to plant, from plant to animal, and from animal to man.”18 Perhaps these views embroiled him with the conservatives of Baghdad; he was forced, he says, “to leave the city where I was born and grew up.” He moved to Cairo, but mourned the separation. “It is the character of our time,” he wrote, “to separate and disperse all…. God makes a nation prosper through love of the hearth; it is a sign of moral uprightness to be attached to the place of one’s birth; it is a mark of noble lineage to dislike separation from the ancestral hearth and home.”19 He died at Cairo in 956, after ten years of exile.
At their best these historians excel in the scope of their enterprise and their interests; they properly combine geography and history, and nothing human is alien to them; and they are far superior to the contemporary historians in Christendom. Even so they lose themselves too long in politics and war and wordy rhetoric; they seldom seek the economic, social, and psychological causes of events; we miss in their vast volumes a sense of orderly synthesis, and find merely a congeries of unco-ordinated parts—nations, episodes, and personalities. They rarely rise to a conscientious scrutiny of sources, and rely too piously upon chains of tradition in which every link is a possible error or deceit; in consequence their narratives sometimes degenerate into childish tales of portent, miracle, and myth. As many Christian historians (always excepting Gibbon) can write medieval histories in which all Islamic civilization is a brief appendage to the Crusades, so many Moslem historians reduced world history before Islam to a halting preparation for Mohammed. But how can a Western mind ever judge an Oriental justly? The beauty of the Arab language fades in translation like a flower cut from its roots; and the topics that fill the pages of Moslem historians, fascinating to their countrymen, seem aridly remote from the natural interests of Occidental readers, who have not realized how the economic interdependence of peoples ominously demands a mutual study and understanding of East and West.
II. SCIENCE*
In those lusty centuries of Islamic life the Moslems labored for such an understanding. The caliphs realized the backwardness of the Arabs in science and philosophy, and the wealth of Greek culture surviving in Syria. The Umayyads wisely left unhindered the Christian, Sabaean, or Persian colleges at Alexandria, Beirut, Antioch, Harran, Nisibis, and Jund-i-Shapur; and in those schools the classics of Greek science and philosophy were preserved, often in Syriac translations. Moslems learning Syriac or Greek were intrigued by these treatises; and soon translations were made into Arabic by Nestorian Christians or Jews. Umayyad and Abbasid princes stimulated this fruitful borrowing. Al-Mansur, al-Mamun, and al-Mutawakkil dispatched messengers to Constantinople and other Hellenistic cities—sometimes to their traditional enemies the Greek emperors—asking for Greek books, especially in medicine or mathematics; in this way Euclid’s Elements came to Islam. In 830 al-Mamun established at Baghdad, at a cost of 200,000 dinars ($950,000), a “House of Wisdom” (Bayt al-Hikmah) as a scientific academy, an observatory, and a public library; here he installed a corps of translators, and paid them from the public treasury. To the work of this institution, thought Ibn Khaldun,20 Islam owed that vibrant awakening which in causes—the extension of commerce and the rediscovery of Greece—and results—the flowering of science, literature, and art—resembled the Italian Renaissance.
From 750 to 900 this fertilizing process of translation continued, from Syriac, Greek, Pahlavi, and Sanskrit. At the head of the translators in the House of Wisdom was a Nestorian physician, Hunain ibn Ishaq (809–73)—i.e., John son of Isaac. By his own account he translated a hundred treatises of Galen and the Galenic school into Syriac, and thirty-nine into Arabic; through his renderings some important works of Galen escaped destruction. Further, Hunain translated Aristotle’s Categories, Physics, and Magna Moralia; Plato’s Republic, Timaeus, and Laws; Hippocrates’ Apho
risms, Dioscorides’ Materia Medica, Ptolemy’s Quadripartitum, and the Old Testament from the Septuagint Greek. Al-Mamun endangered the treasury by paying Hunain in gold the weight of the books he had translated. Al-Mutawakkil made him court physician, but jailed him for a year when Hunain, though threatened with death, refused to concoct a poison for an enemy. His son Ishaq ibn Hunain helped him with his translations, and himself rendered into Arabic the Metaphysics, On the Soul, and On the Generation and Corruption of Animals of Aristotle, and the commentaries of Alexander of Aphrodisias—a work fated to wield great influence on Moslem philosophy.
By 850 most of the classic Greek texts in mathematics, astronomy, and medicine had been translated. It was through its Arabic version that Ptolemy’s Almagest received its name; and only Arabic versions preserved Books V–VII of the Conics of Apollonius of Perga, the Mechanics of Hero of Alexandria, and the Pneumatics of Philo of Byzantium. Strange to say, the Mohammedans, so addicted to poetry and history, ignored Greek poetry, drama, and historiography; here Islam accepted the lead of Persia instead of Greece. It was the misfortune of Islam and humanity that Plato, and even Aristotle, came into Moslem ken chiefly in Neoplatonic form: Plato in Porphyry’s interpretation, and Aristotle discolored by an apocryphal Theology of Aristotle written by a Neoplatonist of the fifth or sixth century, and translated into Arabic as a genuine product of the Stagirite. The works of Plato and Aristotle were almost completely translated, though with many inaccuracies; but as the Moslem scholars sought to reconcile Greek philosophy with the Koran, they took more readily to Neoplatonist interpretations of them than to the original books themselves. The real Aristotle reached Islam only in his logic and his science.
The continuity of science and philosophy from Egypt, India, and Babylonia through Greece and Byzantium to Eastern and Spanish Islam, and thence to northern Europe and America, is one of the brightest threads in the skein of history. Greek science, though long since enfeebled by obscurantism, misgovernment, and poverty, was still alive in Syria when the Moslems came; at the very time of the conquest Severus Sebokht, abbot of Ken-nesre on the upper Euphrates, was writing Greek treatises on astronomy, and was making the first known mention of Hindu numerals outside of India (662). The Arabic inheritance of science was overwhelmingly Greek, but Hindu influences ranked next. In 773, at al-Mansur’s behest, translations were made of the Siddhantas—Indian astronomical treatises dating as far back as 425 B.C.; these versions may have been the vehicle through which the “Arabic” numerals and the zero were brought from India into Islam.21 In 813 al-Khwarizmi used the Hindu numerals in his astronomical tables; about 825 he issued a treatise known in its Latin form as Algoritmi de numero Indorum—“al-Khwarizmi on the Numerals of the Indians”; in time algorithm or algorism came to mean any arithmetical system based on the decimal notation. In 976 Muhammad ibn Ahmad, in his Keys of the Sciences, remarked that if, in a calculation, no number appears in the place of tens, a little circle should be used “to keep the rows.”22 This circle the Moslems called sifr, “empty” whence our cipher; Latin scholars transformed sifr into zephyrum, which the Italians shortened into zero.
Algebra, which we find in the Greek Diophantes in the third century, owes its name to the Arabs, who extensively developed this detective science. The great figure here—perhaps the greatest in medieval mathematics—was Muhammad ibn Musa (780–850), called al-Khwarizmi from his birthplace Khwarizm (now Khiva), east of the Caspian Sea. Al-Khwarizmi contributed effectively to five sciences: he wrote on the Hindu numerals; compiled astronomical tables which, as revised in Moslem Spain, were for centuries standard among astronomers from Cordova to Chang-an; formulated the oldest trigonometrical tables known; collaborated with sixty-nine other scholars in drawing up for al-Mamun a geographical encyclopedia; and in his Calculation of Integration and Equation gave analytical and geometrical solutions of quadratic equations. This work, now lost in its Arabic form, was translated by Gerard of Cremona in the twelfth century, was used as a principal text in European universities until the sixteenth century, and introduced to the West the word algebra (al-jabr—“restitution,” “completion”). Thabit ibn Qurra (826–901), besides making important translations, achieved fame in astronomy and medicine, and became the greatest of Moslem geometers. Abu Abdallah al-Battani (850–929), a Sabaean of Raqqa known to Europe as Albategnus, advanced trigonometry far beyond its beginnings in Hipparchus and Ptolemy by substituting triangular for Ptolemy’s quadrilateral solutions, and the sine for Hipparchus’ chord; he formulated the trigonometrical ratios essentially as we use them today.
The Caliph al-Mamun engaged a staff of astronomers to make observations and records, to test the findings of Ptolemy, and to study the spots on the sun. Taking for granted the sphericity of the earth, they measured a terrestrial degree by simultaneously taking the position of the sun from both Palmyra and the plain of Sinjar; their measurement gave miles—half a mile more than our present calculation; and from their results they estimated the earth’s circumference to approximate 20,000 miles. These astronomers proceeded on completely scientific principles: they accepted nothing as true which was not confirmed by experience or experiment. One of them, Abu’l-Farghani, of Transoxiana, wrote (c. 860) an astronomical text which remained in authority in Europe and Western Asia for 700 years. Even more renowned was al-Battani; his astronomical observations, continued for forty one years, were remarkable for their range and accuracy; he determined many astronomical coefficients with remarkable approximation to modern calculations—the precession of the equinoxes at 54.5″ a year, and the inclination of the ecliptic at 23° 55′.23 Working under the patronage of the early Buwayhid rulers of Baghdad, Abu’l-Wafa (in the disputed opinion of Sadillot) discovered the third lunar variation 600 years before Tycho Brahe.24 Costly instruments were built for the Moslem astronomers: not only astrolabes and armillary spheres, known to the Greeks, but quadrants with a radius of thirty feet, and sextants with a radius of eighty. The astrolabe, much improved by the Moslems, reached Europe in the tenth century, and was widely used by mariners till the seventeenth. The Arabs designed and constructed it with aesthetic passion, making it at once an instrument of science and a work of art.
Even more important than the charting of the skies was the mapping of the earth, for Islam lived by tillage and trade. Suleiman al-Tajir—i.e., the merchant—about 840 carried his wares to the Far East; an anonymous author (851) wrote a narrative of Suleiman’s journey; this oldest Arabic account of China antedated Marco Polo’s Travels by 425 years. In the same century Ibn Khordadhbeh wrote a description of India, Ceylon, the East Indies, and China, apparently from direct observation; and Ibn Hauqal described India and Africa. Ahmad al-Yaqubi, of Armenia and Khurasan, wrote in 891 a Book of the Countries, giving a reliable account of Islamic provinces and cities, and of many foreign states. Muhammad al-Muqaddasi visited all the lands of Islam except Spain, suffered countless vicissitudes, and in 985 wrote his Description of the Moslem Empire—the greatest work of Arabic geography before al-Biruni’s India.
Abu al-Rayhan Muhammad ibn Ahmad al-Biruni (973–1048) shows the Moslem scholar at his best. Philosopher, historian, traveler, geographer, linguist, mathematician, astronomer, poet, and physicist—and doing major and original work in all these fields—he was at least the Leibniz,25 almost the Leonardo, of Islam. Born like al-Khwarizmi near the modern Khiva, he signalized again the leadership of the Transcaspian region in this culminating century of medieval science. The princes of Khwarizm and Tabaristan, recognizing his talents, gave him a place at their courts. Hearing of the bevy of poets and philosophers at Khwarizm, Mahmud of Ghazni asked its prince to send him al-Biruni, Ibn Sina, and other savants; the prince felt obliged to comply (1018), and al-Biruni went to live in honor and studious peace with the bellicose ravisher of India. Perhaps it was in Mahmud’s train that al-Biruni entered India; in any case he stayed there several years, and learned the language and the antiquities of the country. Returning to Mahmud’s court, he became a fav
orite of that incalculable despot. A visitor from northern Asia offended the king by describing a region, which he claimed to have seen, where for many months the sun never set; Mahmud was about to imprison the man for jesting with royalty when al-Biruni explained the phenomenon to the satisfaction of the king and the great relief of the visitor.26 Mahmud’s son Masud, himself an amateur scientist, showered gifts and money upon al-Biruni, who often returned them to the treasury as much exceeding his needs.
His first major work (c. 1000) was a highly technical treatise—Vestiges of the Past (Athar-ul-Baqiya)—on the calendars and religious festivals of the Persians, Syrians, Greeks, Jews, Christians, Sabaeans, Zoroastrians, and Arabs. It is an unusually impartial study, utterly devoid of religious animosities. As a Moslem al-Biruni inclined to the Shia sect, with an unobtrusive tendency to agnosticism. He retained, however, a degree of Persian patriotism, and condemned the Arabs for destroying the high civilization of the Sasanian regime.27 Otherwise his attitude was that of the objective scholar, assiduous in research, critical in the scrutiny of traditions and texts (including the Gospels), precise and conscientious in statement, frequently admitting his ignorance, and promising to pursue his inquiries till the truth should emerge. In the preface to the Vestiges he wrote like Francis Bacon: “We must clear our minds … from all causes that blind people to the truth—old custom, party spirit, personal rivalry or passion, the desire for influence.” While his host was devastating India al-Biruni spent many years studying its peoples, languages, faiths, cultures, and castes. In 1030 he published his masterpiece, History of India (Tarikh al-Hind). At the outset he sharply distinguished between hearsay and eyewitness reports, and classified the varieties of “liars” who have written history.28 He spent little space on the political history of India, but gave forty-two chapters to Hindu astronomy, and eleven to Hindu religion. He was charmed by the Bhagavad Gita. He saw the similarity between the mysticism of the Vedanta, the Sufis, the Neopythagoreans, and the Neoplatonists; he compared excerpts from Indian thinkers with like passages from Greek philosophers, and expressed his preference for the Greeks. “India,” he wrote, “has produced no Socrates; no logical method has there expelled fantasy from science.”29 Nevertheless he translated several Sanskrit works of science into Arabic, and, as if to pay a debt, rendered into Sanskrit Euclid’s Elements and Ptolemy’s Almagest.