Pathfinders

by Jim Al-Khalili

  It is interesting to note that while a number of significant Jewish philosophers and scientists made invaluable contributions to the intellectual culture of Baghdad, their work was almost entirely in Arabic rather than Hebrew. A good example lies with the work of Sahl Rabbān al-Tabari (c. 786–845), who came to Baghdad and is said to have made one of the first translations of Ptolemy’s Almagest into Arabic. This Jewish astronomer and physician, whose name literally means ‘the son of the rabbi of Tabaristan’ – by reference to a province in northern Iran – settled in Baghdad during the time of al-Rashīd. His son, Ali (c. 838–70), who converted to Islam, wrote the first Arabic encyclopedia of medicine and would tutor a boy named Muhammad ibn Zakariyya al-Rāzi, who was destined to become one of the greatest clinicians who ever lived.

  Some historians have claimed that despite the Abbāsids’ admiration of all things Persian and, by association, their link to Indian science and culture in the East, the whole of the translation movement was built on what was originally Greek science.8 To some extent this is true. The expansion of Alexander the Great’s empire as far east as India, many centuries before Islam, carried the fruits of Greek science far beyond its home shores – although we should not forget the sea trade routes from Egypt as a separate avenue of transmission. This knowledge, one can argue, eventually made the circuitous journey from its Greek origins, via India, back to the palace courts of Abbāsid Baghdad. Much of Greek knowledge also reached the Arabic world through the great Christian cities of Antioch and Edessa where, to a lesser extent, a translation tradition from Greek to Syriac had flourished in the centuries before Islam’s arrival.

  Certainly in the fields of medicine and philosophy, where Hippocrates, Galen, Plato and Aristotle were peerless, the Arabs had the Greeks to thank for almost the entirety of their knowledge. In geometry, too, the Indians and Persians could claim little expertise. But it is unfair to dismiss their contribution to the development of Arabic science completely during the translation movement. For without its exposure to Indian mathematics, the Muslim world would not have had the decimal numbering notation, or the kick-start in trigonometry that was to prove so useful in astronomy. Similarly, Arabic astronomy is seen as a continuation of the work of the Persian observatories, which itself would not have flourished without Indian mathematics.

  An alternative and erroneous view, more sympathetic to Persian culture and history, is based on an interesting myth that is worth recounting here. In 333 BCE, Alexander the Great conquered the Persian Empire and deposed its last king, Darius III. Alexander marched on the Persian capital at Persepolis, where he found writings on the various sciences and branches of knowledge regarded by Persians as divine in origin, passed down by the prophet Zoroaster himself. Alexander had all texts translated from Persian into Greek, after which he destroyed the originals. Hundreds of years later, Sasanian kings ordered the collection of all Greek works and their retranslation back into Persian. In this way, Persians justified their use of Greek knowledge in medicine, astronomy and astrology, since they claimed that it was all stolen Persian knowledge anyway.

  As a scholar and a poet himself, al-Rashīd was a great patron of the arts and it was under his rule that Muslim scholars began to study the great works of the Greeks and the Indians in earnest, and to assimilate that knowledge into Arabic culture. Al-Rashīd’s court in Baghdad was full of artists, musicians, poets and theologians from far and wide. But it was his second-in-command and tutor of the young Ma’mūn, the vizier Ja’far al-Barmaki, who oversaw many of the early translation activities. The Barmakis, who had sponsored and supported the Abbāsids’ rise to power and whose loyalty was rewarded by their hereditary appointment as grand viziers (and occasional execution), found they had tremendous power in the day-to-day running of the state. They were, moreover, strong supporters of the translation movement and were able to infuse the caliph’s court with their Persian cultural heritage.

  Another prominent Persian family who sponsored the translation movement was the Bukhtishūs. Several members of this family personally commissioned the translation of medical texts into Arabic. Even before the arrival of the Abbāsids, Persian physicians would already have been familiar with many of the medical texts of Hippocrates and Galen, whose teachings had been practised in Gondēshāpūr. Their chief beneficiary when it came to medical texts was the Christian physician and translator Hunayn ibn Ishāq, who was destined to become the most famous and prolific translator of the age.

  Another scholar of Baghdad to benefit from their generous support was Thābit ibn Qurra (c. 836–901), a pagan from the city of Harrān in north-west Mesopotamia (now in Turkey) who began his working life as a market moneychanger before discovering philosophy. Thābit translated the mathematical work of Euclid, Archimedes, Apollonius and Ptolemy. He also prepared summaries of the works of Aristotle. But he was a brilliant mathematician in his own right and wrote original works on geometry, statics, magic squares and the theory of numbers. He even covered astronomy and, towards the end of his life, was appointed court astronomer by the Abbāsid Caliph al-Mu’tadid. Several of his works were themselves later translated into Latin and were highly influential in the West.

  Another prominent Christian translator in ninth-century Baghdad was a Byzantine Greek by the name of Qusta ibn Luqqa (d. c. 912). Like many of the top translators, he was a polymath who understood mathematics, medicine, astronomy and philosophy. He came originally from the town of Baalbek (Heliopolis) in the Bekaa valley in Lebanon. Like Hunayn ibn Ishāq, he was urged to convert to Islam but never did so. Among the books he translated from Greek to Arabic were those of Diophantus the mathematician, Aristarchus (the first astronomer to propose a heliocentric model of the solar system) and Galen. Qusta wrote many original works on medicine and geometry, and even a treatise on the astrolabe, the most important astronomical device before the telescope (see Plate 14).9

  As Arabic scholarship began in earnest during the first half of the ninth century, with an increasing amount of original writing being commissioned in astronomy, geography, mathematics and medicine, so inevitably did original research in those subjects, generating the need for further texts to be translated, or more careful and accurate translations of Greek texts already existing in Arabic. The knowledge gained from these texts inspired many to dedicate their lives to those subjects. For example, it was part of every scholar’s education in al-Ma’mūn’s Baghdad to study Ptolemy’s Almagest, and it was the knowledge they gained from this important text that led to the first observatories being built in the Islamic Empire, in Baghdad and Damascus during al-Ma’mūn’s reign. He appointed astronomers, who began a systematic programme of careful observations to check the accuracy of Ptolemy’s star charts. This marked the beginning of seven hundred years of Arabic astronomy and provided the bridge from the Greeks to the Copernican revolution in Europe and the birth of modern astronomy.

  Many of the most important Greek texts were translated into Arabic several times. A good example is Euclid’s Elements, which had a huge impact on Islamic mathematics. This was first translated by al-Hajjāj ibn Yūsuf during the reign of al-Rashīd at the beginning of the ninth century. The same man was later to produce a new translation for al-Ma’mūn. But the text was also translated by Hunayn ibn Ishāq, and his version was then revised by Thābit ibn Qurra. Finally, a further revision was made by the astronomer al-Tūsi almost four centuries later. The work probably first became known in Europe through Latin translations of this later version. It has even been claimed that the Elements was known to the Caliph al-Mansūr, who had heard of it from Christian priests and had requested a copy from the Byzantine emperor.10 But the quality of any Arabic translation of the Elements made for al-Mansūr is debatable, as is its usefulness to any of the early Abbāsid mathematicians.

  The translation movement finally came to an end in the second half of the tenth century, not because of a decline in or a loss of interest in scholarship but because it had naturally reached a stage when it was no lon
ger required. All the great works had been translated, retranslated, studied and commented upon and were by this point being replaced by original Arabic works that took the sciences further. Indeed, some of the very greatest Greek texts, such as Ptolemy’s Almagest, were no longer seen as ‘state of the art’ and had been superseded by more sophisticated astronomical works. By this time, the collective scientific enterprise was embedded in Baghdad’s cultural atmosphere of scholarly patronage and competition.

  The first great scientist of Islam, however, predates this period by a generation. His life and achievements are shrouded in mystery and controversy. He is known in the West as Geber the Alchemist.

  4

  The Lonely Alchemist

  We may ask ourselves what men like Gauss or Faraday would have done if they had been born in the eighth or ninth century instead of being able to take advantage of another millennium of human effort.

  George Sarton

  Many of the great scientists of the golden age were not Arabs but Persian, even though they wrote all their work in Arabic, the official language of the empire. This is a source of considerable sensitivity to Iranians and other Central Asian Muslims, who understandably dislike their great heroes being mistaken for Arabs (particularly when the Arabic definite article ‘al’ is attached to their names). To stress to you how difficult it can sometimes be to disentangle the roots and origins of many of these men it might be useful for me to share with you my own somewhat blurred ethnic background.

  The al-Khalīlis (Al-Khalilis)1 are a Shi’a clan from the cities of Najaf and Kūfa in Iraq with strong Persian roots that go back over two hundred years. Around the end of the eighteenth century, my great-great-great-grandfather, Merza Khalil, a prominent physician from Tehran who had originally studied in the city of Qum to become an imam and after whom the Al-Khalili family is named, was on a pilgrimage to Mecca. His trip coincided with that of the Ottoman wali of Baghdad, the administrative ruler of a large chunk of today’s Iraq, who fell ill. Khalil was called upon to treat him with the appropriate herbal remedies that he was an authority on. After recovering, the wali invited him back to Iraq to settle, which he did in 1799. Of his six sons, the eldest, Muhammad, remained in Iran to achieve even greater distinction in medicine than his father by becoming the personal physician to the shah, Nasr al-Dīn Qajar (1831–96), earning him the title of Fakhr al-Atibbā’ (‘The Pride of Physicians’). Naturally, this is a source of great pride to the Al-Khalili clan, even today, for Shah Nasr al-Dīn was one of the greatest rulers in Persian history. A great reformist, he introduced in Iran the postal service, the rail system and newspaper publishing. On a visit to Britain in 1873, accompanied by my great-great-great-uncle Muhammad, the shah was appointed by Queen Victoria a Knight of the Order of the Garter, the highest English order of chivalry.

  I am descended from two of Khalil’s other sons, Bāqir on my grandfather’s side and Merza Hussein on my grandmother’s side. The latter, I always find fascinating to recount, was a spiritual leader of millions of Shi’a Muslims in Ottoman Iraq, Persia, Lebanon and India at the end of the nineteenth century. Based in the city of Najaf, he belonged to the group of mujtahids (clergy with the authority to interpret the Qur’an) and played an important role in the mobilization of public pressure across the Persian border against the excessive corruption and pro-Russian policies of the last of the Qajar rulers prior to Iran’s constitutional revolution of 1905. After the death of the supreme leader Merza Shirazi in Najaf in 1895, Merza Hussein Al-Khalili became the absolute leader of the Shi’a clergy of Najaf. He was responsible for a number of public works, including the building of a canal between Kūfa and Najaf. By the beginning of the twentieth century this great-great-grandfather of mine was given the loftier title of Ayatollah.

  I am thus in the fourth generation of Al-Khalilis to have been born in Iraq. Despite this, Saddam Hussein certainly did not regard the Al-Khalilis as true Iraqis, and many of my relatives were executed during the height of hostilities with Iran in the 1980s for having what were perceived to be divided loyalties. When my father came to Britain to study engineering in the 1950s and met my mother he became the first of the Al-Khalilis to marry outside the clan. It could therefore be argued on ethnic grounds that I have no Arab blood in me at all! Does any of this matter? My point is that while Arabs and Persians are technically different races (Semitic and Arian), the inhabitants of Iraq today are of such a racial mix – Arabs living alongside Assyrians, Kurds, Persians, Armenians and Turkomans – that it is rather pointless to try to lay claim to particular figures in history as belonging to any one race.

  Baghdad was in fact the second capital of the Abbāsids. For a number of years before its foundation they had taken Kūfa, the city of my father’s birth, as their capital. Today, Kūfa is no more than a suburb of the much larger city of Najaf. But in the mid-eighth century, even after the move to Baghdad, Kūfa retained its importance both as a centre of scholarship and the spiritual home of the Shi’a movement that had helped bring the Abbāsids to power. It is in this city that my story of Arabic science really takes off.

  If there is one scientific discipline that can truly be said to have begun in the medieval Islamic world, it is chemistry. And to a large extent this was due to the achievements of one Muslim scholar, working alone in Kūfa in the eighth century.

  Or at least that is one version of history.

  For reasons that will soon become clear, I shall begin by examining the term ‘alchemy’. There is no ambiguity about its meaning today as an irrational, pseudo-scientific belief that base metals can be transmuted into silver and gold, with its origins rooted in myth, legend and superstition. It is commonly thought that, just as astronomy can be shown to have grown out of the much older and non-scientific practice of astrology, so also the science of chemistry emerged from alchemy. This is wrong.

  The first attempts to understand and manipulate matter go back long before Islam. The Egyptians, Babylonians, Greeks, Indians and Chinese all practised and developed a crude form of applied chemistry: in metallurgy, in the production of paints, salts and dyes, and even in the fermentation of alcoholic beverages. Quite independently of such practical concerns, the Greek philosophers were interested in developing theories and rudimentary classifications of the material world, such as the four elements of Empedocles: earth, air, water and fire.2 Aristotle subscribed broadly to this idea but believed that all four were different aspects of the same ‘primary substance’ or protylē, which contains within it the potential to take on all four different forms. This potential is expressed in the effects of the four fundamental qualities of heat, coldness, dryness and humidity. Aristotle also postulated the existence of a fifth element, the aether, which was immutable and imperishable.

  Similar theories appeared around the same time in China, where it was believed that there were five fundamental elements (earth, water, fire, metal and wood) and in India (earth, water, fire, air and space). The question is whether this combination of the philosophy of matter on the one hand and applied chemical processes on the other constitutes what we might define as real chemistry. I would say not; chemistry is a science and as such must satisfy the rigorous requirements of the scientific method. It is more appropriate to call these ancient practices and notions, going back many thousands of years, ‘protochemistry’;3 the pursuit of alchemy can be regarded as a subfield of this protochemistry.

  But what of this Muslim scholar to whom I claim we owe so much? Geber the Alchemist is without doubt one of the most fascinating and enigmatic figures in the history of Arabic science. His real name is Jābir ibn Hayyān (c. 721–c. 815) and he lived before the reign of al-Ma’mūn. I shall be making the case that he be regarded as the father of chemistry, but there are two problems that must be addressed if I am to offer a convincing argument. First, Jābir himself did not help his case by combining in his work some remarkable laboratory chemistry with mystical and bizarre notions and obscure writing that is often extremely hard to follow. In f
act, the origin of the word ‘gibberish’, which goes back to the early sixteenth century, refers to any obscure language ‘such as that used by Gibber (or Jābir)’. Secondly, a huge mythology has grown around his work, fuelled by later Islamic and Christian scholars who wrote under his name, making it hard to determine just what is authentic and what is not. Digging through the vast literature on the subject has been for me both hugely enjoyable and somewhat frustrating, and the debate about Jābir’s place in history still rages.

  Jābir was a Yemeni Arab in origin and the son of an apothecary. He was born in Khurasan in eastern Persia, where the Abbāsid revolution began. But with the founding of the new empire, he moved with his family to Kūfa where he began practising medicine. His father had been politically very closely allied with the Persian Barmaki family and so Jābir came to be regarded by them as a loyal and trustworthy character. He received their generous patronage, in particular that of Ja’far, the grand vizier of al-Rashīd.

  It is thought that Jābir had a Baghdad residence near the Damascus Gate, but most of his time seems to have been spent in Kūfa, because of the ‘healthiness of the climate’ there. When, in 802, al-Rashīd had his vizier Ja’far executed in order to curtail the influence of the Barmaki family, Jābir, now an old man, lost his elevated status in the caliph’s court and spent his remaining years under house arrest.

  To his many followers, Jābir was known as al-Sūfi (the Mystic) and certainly much of his work was tied in with mysticism and magic. But a number of contemporary historians have downplayed the alchemical side of his work and point to this quotation from the prologue of one of his most famous books, Kitab al-Rahma al-Kabīr (The Great Book of Mercy), where Jābir is critical of those who practise the ‘art’ of transmutation: