Flying Man

In​ the early 11th century, at Nandana, a fort in the mountains of northern Punjab, the polymath Abu Rayhan al-Biruni realised his dream of measuring the size of the earth. Two centuries earlier, the Abbasid caliph al-Ma’mun had sent a group of astronomers into the desert for the same purpose. The advantage of Biruni’s method was that it ‘did not require walking in deserts’. He simply calculated the height of one of the mountains and the angle it formed with the horizon on the plain below. He could then construct a triangle, one of whose sides was the height of the mountain plus the earth’s radius. Trigonometry would do the rest. The circumference Biruni calculated (after some later revisions) came within just eighty miles of modern measurements. Only in the 17th century would Europeans improve on his figures.

Biruni is one of S. Frederick Starr’s subjects in The Genius of Their Age, a joint biography of two of the most brilliant and versatile thinkers of the time. His restless curiosity led him to discoveries in astronomy, mathematics, mineralogy, pharmacology and history. Starr’s other subject, Ibn Sina (known to Westerners as Avicenna), also wrote widely – on mathematics, geology, good governance – but he is chiefly remembered for his work in philosophy and medicine.

The two men were born within a few years of each other – Biruni in 973 and Ibn Sina a little before 980. They were both from the Central Asian region of Khwarazm, a nexus on the Silk Road, in what is now Uzbekistan and Turkmenistan. They lived through frequent dynastic changes, as the area passed from one local ruler to another and from Samanid to Ghaznavid control, and made several dramatic escapes from advancing enemy armies. Their methods illustrate two sides of the Islamic intellectual tradition: while Biruni was an incrementalist, setting out to solve concrete problems, Ibn Sina was a panoramic thinker in search of a systematic account of the universe. Though the two men are known to have met and had a lengthy correspondence, they never cited one another in their work, an omission that hints at the deep rivalry between them.

Biruni’s life emerges from his writings as a footnote to his science. In one study, he notes that ‘the moment of my birth occurred in the city of Khwarazm, whose latitude northward is 41°20’ and whose distance from Baghdad is one complete level hour eastward, on Thursday, 3 Dhu al-Hijja, in the year 362.’ (We can work this out as 4 September 973.) Biruni’s reticence about his origins has led modern scholars to speculate that he may have been orphaned or abandoned, or even (depending on the interpretation of a contemporary poem) that he was the illegitimate son of royalty. He was taken up at a young age by the Iraq family, who governed Khwarazm on behalf of the Samanids of Bukhara and supported his first forays into mathematics and astronomy, including the construction of a globe, five metres wide, for pinpointing the location of cities. At the turn of the 11th century, however, the Samanid empire began to disintegrate, and with it the fortunes of his patrons. Biruni began a peripatetic life in search of financial support and new outposts for astronomical observations, visiting stations in Afghanistan, India, Iran, Pakistan and Turkmenistan. By the time he reached his seventies, his stargazing had left him almost blind. He died in 1048, by some accounts consulting an Afghan scholar on contract law from his deathbed. When the scholar expressed surprise at Biruni’s curiosity under the circumstances, he replied: ‘Is it not better for me to leave this world knowing the answer to this question than not knowing it?’

Biruni’s projects were so diverse that it is difficult to do them justice: he devised new techniques for measuring longitude, predicted the existence of continents beyond Afro-Eurasia and introduced trigonometric functions that are still in use today. His Chronology of Ancient Nations gives us a sense of his intellectual idiosyncrasy. Completed around 1000, it was an ambitious attempt to make different systems for measuring time accord with one another. Biruni conducted extensive research into the ancient Greek, Persian, Nestorian Christian, Jewish and Central Asian calendars, comparing their creation narratives and the various ways in which they accounted for the six ‘excess’ hours that accrue every 365 days. Starr marvels at the fair-mindedness with which Biruni described these chronographies: whereas earlier writers ‘applied their own cultural measure to everyone else, Biruni began with the assumption that all cultures were equal’. He plotted each of the calendars onto a circular device that allowed the user to translate dates from one system to another, creating, in Starr’s estimation, ‘the first global system for measuring the passage of time’.

Ibn Sina was born to a Persian bureaucratic family in a town near Bukhara, where he was trained in Islamic law, ancient philosophy and medicine. When the ruler of Bukhara, Nuh ibn Mansur, fell ill, Ibn Sina was one of the doctors called on for a cure. He was rewarded with unfettered access to the royal library. In the decades that followed, political unrest and the search for patrons led him, like Biruni, to courts across Central Asia. Though a theoretician, he was not unworldly: he served various local rulers as vizier and boasted of his wine drinking and salon exploits (one of his enemies insinuated that he died thanks to his voracious sexual appetite). He could also be cantankerous, labelling his enemies ‘shit-eaters’ and ‘dung beetles’.

The abstraction and density of Ibn Sina’s work makes it more difficult to appreciate than Biruni’s, but he was far more influential. His great philosophical achievement was to have made the concerns of the ancient Greek thinkers compatible with the Islamic tradition. For centuries after his death, to practise falsafa – Arabic for ‘philosophy’ – was to be a partisan of Ibn Sina. But he didn’t simply interpret Aristotle, he supplanted him, finding new ways to characterise the human soul as immaterial and separate from the body. His ‘flying man’ thought experiment proposed that a person created by God with no memories and no immediate sensory input (hence ‘flying’) would nonetheless be aware of his self. His most influential work was his proof for the existence of God, who was postulated as the ‘necessary existent’ behind the universe but not the immediate cause of all actions or things. His medical writing was equally ambitious. The Canon of Medicine, a five-volume encyclopedia he completed in 1025, systematised all contemporary medical knowledge, theoretical and practical, into a single framework, from its philosophical underpinnings to its applications in diagnosis, treatment and prevention.

Starr’s subtitle suggests that this book should be seen as a sequel to Lost Enlightenment (2013), in which he argued that Central Asia was the intellectual centre of the medieval world, until enlightened thinking was finally suppressed by conservative religious forces. Biruni and Ibn Sina illustrate the region’s cosmopolitanism and ingenuity. While being grounded in the pluralistic tradition of Islamic learning, they spent a lifetime in dialogue with Greek texts: not just Aristotle (about whom they had a lively epistolary exchange), but also Galen’s writings on medicine and Ptolemy’s on geography and astronomy. They drew inspiration from South Asian mathematical and medical traditions; Biruni translated Hindu religious and philosophical texts, including Purana epics and the Yoga Sutra of Patanjali. His Pharmacology, which compared plants from many parts of the known world, named species in twenty different languages. This diversity of influence was the result of Central Asia’s position at the crossroads of Asia and Europe: Biruni first learned about materia medica from a Byzantine man who had settled in his home town, and in his forties travelled to India in the entourage of his patron Mahmud, who ruled over a wide stretch of the region from western Iran to the Punjab from his base in Ghazni.

This intellectual crucible produced many other scholars whom Starr might have discussed – Muhammad al-Bukhari, for example, who lived in the ninth century and compiled a collection of prophetic accounts so comprehensive and authoritative that it is consulted by Muslims to this day. Bukhari, however, is of little interest to Starr, perhaps because his life’s project, unlike those of Ibn Sina and Biruni, was conducted in the service of faith. Biruni’s greatest interest was the natural world, and when he did deal with Islam it was with the same disinterestedness he applied to other religions (among his criticisms of early Muslims was that they had refused to introduce leap years into their calendar). Ibn Sina subjected everything, including the existence of God, to rational scrutiny, in ways that caused his contemporaries, as well as modern scholars, to doubt his piety.

Starr appears to have chosen these two thinkers because they seem compatible with Western modernity. Ibn Sina was the most important guide to Aristotle’s metaphysics in Latin Christianity until he was displaced by Ibn Rushd (Averroes) in the late 12th century. The Canon of Medicine was a staple of European medical curricula until the 17th century: nearly sixty editions were printed between 1500 and 1674. The case for Biruni’s influence is harder to make. Tenuous links to Copernicus notwithstanding, he wasn’t widely known in Europe until the 19th century. Instead, Starr insists that Biruni’s ideas anticipated European ones: not only did he show that planetary orbits must be elliptical centuries before Johannes Kepler, but his conclusion that it is mathematically irrelevant whether the sun rotates around the earth or the earth around the sun prefigured the theories of relative motion developed by Newton, Descartes and Einstein.

While Starr is to be applauded for drawing attention to a region whose history is often overlooked, it’s a shame that The Genius of Their Age treats greatness as a zero-sum game, with Central Asian achievements coming at the expense of those of Arabs, Turks and pious Muslims. Arabs make cameo appearances in order to ravage open and progressive societies; Turks are represented by Mahmud of Ghazni, a ‘sinister and aggressive force’ who used Islam to justify his thirst for conquest; and the Muslim faithful appear, chiefly in the book’s final chapters, as fundamentalist theologians who stifled scientific inquiry and fomented sectarianism. Never mind that neat ethnic categories are hard to sustain when writing about such a mobile, polyglot society, or that much of the region’s intellectual vibrancy resulted from cross-pollination between linguistic groups. Starr’s demonisation of some of these groups as enemies of learning is dangerous and baseless. Arabs sponsored the great translation movement that rendered Greek texts into Arabic in eighth to tenth-century Baghdad, without which Ibn Sina’s work would have been impossible. Turkish-speaking residents of the Ottoman Empire carried Ibn Sina’s logical and philosophical tradition into the 19th century, as the painstaking work of the historian Khaled el-Rouayheb has recently shown. Nor did the forces of Islamic orthodoxy put an end to the era’s intellectual vigour. Though Avicennian falsafa did fall into disrepute, epistemological and metaphysical inquiry continued, along with the study of astronomy, geography, mathematics and medicine. But understanding this requires dispensing with the categories and attitudes derived from the European experience and adopting a more culturally specific notion of what constitutes ‘science’. It also requires absorbing the implications of recent scholarship, including critiques of Lost Enlightenment.

The book’s distortions stem for the most part from Starr’s political agenda. He is the founder and chairman of the Central Asia-Caucasus Institute, a research and policy centre that promotes North American and European involvement in the region. His ideal Central Asia mirrors that of The Genius of Their Age, with its light-touch Islam, scientific spirit and wide networks of commerce. It’s a region free of Arab or Turkish meddling and of sectarianism, more open to ‘worldly’ – that is, Western – ideals. Starr shares this vision with many policy-makers of his generation, though it feels increasingly outdated. Finding indigenous models for Central Asia’s future is a worthwhile endeavour, but shouldn’t we, like Biruni, attempt to study its history without applying our own cultural measures?

Biruni’s efforts to measure the earth’s radius were more complicated than they appear in Starr’s book. One modern researcher has speculated that, struggling with his observations, Biruni instead calculated the angle to the plain using the height of the mountain and the known length of one of the earth’s degrees of circumference. Biruni doubted the accuracy of his results, as he made clear in his account of the enterprise. Demonstrating a commitment to the truth even when it contradicted his own hypothesis, he suggested that it was better to accept the value determined by al-Ma’mun’s team in the desert: ‘Their instrument was more refined, and they took greater pains in its accomplishment.’