Pathfinders

by Jim Al-Khalili

  Although al-Kindi was the first philosopher of Islam, he was certainly not unique in applying Aristotelian philosophy to religious thinking. Other, non-Muslim philosophers before him had also held that revelation in the monotheistic religions was about the discovery of absolute truths about God and man’s place in God’s universe, as discovered through logical philosophical enquiry.

  Parallels can be drawn between al-Kindi and an earlier Alexandrian Christian philosopher named John Philoponus (490–570), an early critic of Aristotle and the first to combine scientific cosmology (the study of the nature of the universe) with the Christian doctrine of creation. The most important difference between Aristotle and Philoponus was that, for the latter, the universe is the single creation of a single God and therefore could not be eternal. Philoponus also held that the stars were not divine but in some sense had the same physical attributes as the earth.

  Both al-Kindi and the Mu’tazilite theologians made use of Philoponus’ arguments to establish their notions regarding the creation of the universe. The Mu’tazilites adopted the doctrine of creation ex nihilo (‘out of nothing’), as did al-Kindi. And even beyond the Mu’tazilite circles, this was a common view among the scholars of Baghdad at the time, such as the Christian Job of Edessa (b. c. 760 CE) and the Jewish philosopher Saadia Gaon (882–942). So it is not that al-Kindi was a particularly close adherent of Mu’tazilite doctrine; rather, again, we see it as part of the general intellectual atmosphere of the time.

  Al-Kindi’s most important treatise, On First Philosophy, was an invitation to Muslim scholars to study Islam philosophically. Many theologians at the time and since have criticized him for this, thinking that he was attempting to replace revelation with rationalism. He was not. In the preface to On First Philosophy, he explains why the study of Greek philosophy is so important. He says that one should not neglect the achievements of previous scholars on the basis that they are of a different race, culture or creed and he accuses those who fail to appreciate the contribution of the Greeks of being narrow-minded, envious and lacking in pure faith in Islam:

  We should not be ashamed to recognise truth and assimilate it, from whatever quarter it may reach us, even though it may come from earlier generations and foreign peoples. For the seeker after truth there is nothing of more value than truth itself; it never cheapens or debases the seeker, but ennobles and elevates him.4

  Since Aristotle’s universe was eternal and uncreated, al-Kindi had to come up with a strongly reasoned logical argument to refute it. He thus adapted one of Philoponus’ proofs of the creation of the universe based on the idea of the impossibility of infinity; namely, that the present moment could never have been reached if it were preceded by infinite time made up of a continuous and infinite sequence of events, which could not have been traversed to reach ‘now’. Unlike Aristotle, al-Kindi demonstrated his ideas mathematically. Here is a neat summary of his argument. If one starts with an infinite quantity and subtracts from it a finite quantity, A, then the remainder, B, is either finite or infinite. If it is finite, then adding it back to A will always give another finite quantity, and not the original infinity. Therefore, B cannot be finite and must be infinite. But subtracting the finite quantity A from the original infinity means that B must be a smaller fraction of this infinity. And fractions, argues al-Kindi, must have limits. So it cannot be infinite. Therefore the whole notion of an infinite quantity is absurd.

  Of course, we know in mathematics today that al-Kindi was wrong, since there are indeed infinities of different ‘sizes’. We can even subtract one infinity from another with the remainder still being infinite. For example, take the infinity of all integer numbers and subtract from it the infinity of all even numbers. You are still left with the infinity of all odd numbers.

  Al-Kindi’s rationale about the impossibility of infinite quantities, including time, led him to the notion not only that the universe could not have existed for ever, but that time itself could not have existed before the creation of the universe and must have come into being together with the universe. This idea is remarkably close to our current understanding of modern cosmology based on the birth of space and time at the Big Bang billions of years ago, as described by Einstein’s General Theory of Relativity. Furthermore, this finiteness of the universe allowed al-Kindi, in contrast to Aristotle, to call upon God as creator of the world who brings it into being out of nothing.

  These philosophical ideas were essentially driven by theology, but al-Kindi was much more than a philosopher. If you thought al-Khwārizmi was versatile in spanning astronomy, geography and mathematics, you should be far more impressed with al-Kindi’s résumé. For in addition to his philosophical writing he also made major contributions to mathematics, astronomy, optics, medicine, music and cryptography. And while it was quite common for scholars, almost up to the modern age, to cover a range of disciplines, few made such an impact across so many fields as al-Kindi. Like that of his contemporary al-Khwārizmi, it was al-Kindi’s influence on future generations that marked him out as such an important figure in the history of science. In mathematics, for instance, both men played an important role in introducing Indian numerals to the Islamic and, later, Christian worlds. Like al-Khwārizmi, al-Kindi was to write an important treatise, The Book on the Use of Indian Numerals (Kitab fi Isti’mal al-’Adad al-Hindi), on the subject.

  In cryptography, he famously devised new methods of code-making and -breaking – or at least provides the earliest known description – and he is credited with developing what is known as the frequency analysis method, whereby variations in the frequency of the occurrence of letters could be analysed and exploited to break ciphers. His work is detailed in a text rediscovered in 1987 in the Sulaimaniyya Ottoman Archive in Istanbul.5 Fascinatingly, al-Kindi’s motivation for developing his expertise in cryptanalysis seems to have arisen from his determination to decipher and translate texts from foreign languages unfamiliar to him. One can almost imagine him impatiently urging and cajoling his translators to speed up their work on important Greek treatises and, unable to wait, inventing ways of deciphering the unfamiliar text himself. Armed with the correct translation of just a few words, he would begin by determining the frequency with which different letters appeared in a particular text, and then progress to making associations between different letters and words until he had cracked the code of a language and whole sentences could be understood.

  He was also the first great theoretician of music in the Arab-Islamic world. He surpassed the achievement of the Greek musicians in using the alphabetical annotation for one-eighth. He also realized the therapeutic value of music and attempted to cure a quadriplegic boy with music therapy. He is known to have written many texts on music theory, of which five have survived. In one, the word mūsīqa, from the Greek word mousikē (meaning ‘art of the Muses’), was used for the first time in Arabic.

  Al-Kindi carefully discriminated between what he saw as science and what he believed to be superstition. He regarded ‘the art’ (alchemy) as a deception and the whole notion of transmutation of base metals into gold as a sham, something he makes clear in his treatise The Deceits of the Alchemists.6 But he believed in astrology unconditionally, although he at least tried to rationalize it scientifically and to distinguish it from its more populist association with horoscopes and fortune-telling. On the other hand, he accepted clairvoyance and divination by dreams as true, and attempted to understand dreams through a form of crude psychology. Before we are too dismissive of such backward notions, we should consider the number of people around the world today who still hold such views; even some of the giants of nineteenth-century science were themselves deeply committed to research into the paranormal.

  Al-Kindi was still relatively young when al-Ma’mūn died, and he continued to serve under several caliphs, starting with al-Ma’mūn’s successor, al-Mu’tasim (833–42), dedicating many of his most important treatises to him. But al-Mu’tasim and his son al-Wāthiq reigned for just nine and f
ive years respectively. They were followed by al-Wāthiq’s younger brother al-Mutawakkil (847–61), who, in stark contrast to all the previous Abbāsid caliphs, showed little interest in science and scholarship, and was to turn against rationalism in favour of a more literalist interpretation of the Qur’an and Hadīth that brought al-Ma’mūn’s mihna to an end. We have no reason to believe that al-Kindi himself supported the mihna, of course. He was even critical of some of the ideas of Mu’tazilism itself, as can be found in the opening chapter of his On First Philosophy,7 which he wrote during the reign of al-Mu’tasim.

  In al-Mutawakkil, we see the first of a line of more conservative caliphs and the beginning of the backlash against the free-thinking and liberal theology of the Mu’tazilite movement. And al-Mutawakkil’s often violent persecution of scholars whose views did not accord with his more fundamentalist version of Islam sees the theological pendulum swinging away from al-Ma’mūn’s mihna to the other extreme; neither ruler endeared himself to those who did not share his views. Even al-Kindi was not spared. While not a Mu’tazilite himself, he broadly sympathized with their views and now suddenly found himself on the wrong side. He fell victim to what seems to have been a conspiracy led by the powerful Banū Mūsa brothers, who cultivated a mischievous streak bordering on the dangerous towards anyone who crossed their path.

  The brothers had grown jealous of al-Kindi’s extensive library and knew that the only way to lay their hands on it was to plot and scheme against him until they finally persuaded the caliph to expel him. Al-Kindi was physically beaten, his library confiscated and its contents granted to the brothers. But they did not keep them for long; having been requested by the caliph to build a canal, their engineer made such a shoddy job of the project that they begged a colleague, Sind ibn Ali, to put in a good word on their behalf with the caliph to get them off the hook. Sind appears to have agreed to do this on the proviso that they return al-Kindi’s library.8

  Despite having his library restored to him, al-Kindi lived his remaining years a lonely man. After his death, his philosophical work quickly fell into obscurity and many of his texts were lost even to later Islamic scholars and historians. A few have survived, however, in the form of Latin translations, while others have been rediscovered in Arabic manuscripts. Even so, all this amounts to only a fraction of his total output as cited in other sources. One reason for the loss of so much of his work may have been the Mongol destruction of the House of Wisdom library in 1258.9

  Al-Kindi’s legacy was not entirely forgotten, and the baton would eventually pass on to a philosopher in the tenth century of Turkish descent, by the name of al-Farābi, who would continue al-Kindi’s mission of the Islamization of Greek philosophy, particularly the work of Aristotle. Al-Farābi’s philosophy built on, extended and even eclipsed the work of al-Kindi. And while it was al-Kindi who first introduced philosophy as the handmaiden of theology, positioning him closer to a traditionalist version of Islam than al-Farābi, it was the latter who attempted a more serious and mature understanding of revelation and prophecy from a purely philosophical point of view. According to al-Kindi, the goal of metaphysics is the knowledge of God, for he believed that both philosophy and theology are concerned with the same subject. Al-Farābi strongly disagreed, and argued that metaphysics is actually concerned with what can be asserted about the proof of God’s existence, but says nothing about His nature or qualities.

  Another difference is that, whereas al-Kindi believed that divine revelation trumped rational reasoning where the two conflicted, such as with the issue of the resurrection of the body on Judgement Day, al-Farābi held that rational philosophical reasoning was more powerful than the symbolic expressions of revealed truths in religion; this despite the fact that he lived in a time when the backlash against philosophers had already begun and with the rationalist Mu’tazilite ideology in retreat and widely viewed with hostility.

  Still, while al-Farābi was to extend his predecessor’s ideas and has certainly been quoted more widely by later philosophers, partly due to the survival of more of his work, in my view he is not quite as worthy of greatness. For al-Farābi was no polymath, nor was he particularly interested in empirical science. Like many of the Greek philosophers before him, he was less concerned with physics than with metaphysics. In contrast, al-Kindi was the true Renaissance man of Islam.

  The philosophical baton would eventually pass from al-Farābi to two men who achieved far greater prominence in Europe than either al-Kindi or al-Farābi and would greatly influence many Renaissance thinkers. They were Ibn Sīna and Ibn Rushd, both of whom being more familiar in the West by their Latinized names: Avicenna and Averroës. But these men achieved what they did only because of the ground laid by al-Kindi. His work in synthesizing Aristotle’s teachings with Islamic theology should be viewed as a vital link in an unbroken chain connecting the philosophy of ancient Greece with modern Western philosophy developed by such men as Thomas Aquinas and Descartes. It is a shame that his name is not often mentioned in modern accounts of the history of philosophy.

  And so we finally leave behind the time of al-Ma’mūn. Many of the scholars he recruited outlived him to continue the pursuit of his dream. Thanks to al-Ma’mūn, the seed had been sown, and even the waning of Mu’tazilism could not halt the rapid flowering of science in the empire. This passion to understand the world became more widespread, both in Baghdad and elsewhere. With the death of al-Kindi and al-Khwārizmi a new era would begin. Scientific progress in the Islamic world gathered pace and new heroes emerged. By the end of the ninth century and the beginning of the tenth, Baghdad would be dominated by a man who became unquestionably the greatest physician of the medieval world. He is known in the West as Rhazes.

  10

  The Medic

  The physician must pay attention to the patient’s strength, the matter of the disease, and its duration; for if the strength is weak, but the disease-matter plentiful and the duration long, then the patient should be offered from the very beginning something which sustains the strength while not increasing the disease-matter – and there is nothing more appropriate for that than the right amount of chicken broth.

  Ya’qūb ibn Ishāq,1 Treatise on the Errors of the Damascene Physicians

  ‘Jiddū’, as we used to call him, died when I was just 6 years old. I still remember his bristly beard and his stethoscope, and his kind gentle eyes – and the books, so many books. Jiddū was my paternal grandfather in Najaf. Our family trips down from Baghdad to visit my grandparents were the only occasions when my mother had to wear an abāya, the black full-body form of hijab worn by women in the Middle East. This was necessary in the holy cities of Najaf and Kerbala, even for Europeans like my mother.

  Thinking back about Jiddū, he so naturally fits the mould of those grand Abbāsid scholars one thousand years earlier. Most of the images one can find today of the great scientists of Islam tend to be stylized artistic depictions by nineteenth-century Europeans, and all entirely fictitious. The only criteria seem to be that the characters need a turban, a beard (of various shades and lengths) and a flowing gown, and be seated on a rug with a book. That is precisely how I remember my grandfather (see Plate 4). And not only did he look the part, he was every bit the scholar himself. He was highly intelligent, wise and well-read. He was first and foremost a writer and poet of some distinction in Iraq. But he was also the local ‘wise man’ and apothecary in his district of Najaf – hence the stethoscope. I remember his library in an upstairs room of the house, which was kept unchanged after he died. Over the years I often spent time in there looking through his books. To be honest, I never found anything as much worth reading as whatever I had on the go at the time, whether it was Just William or The Famous Five, or the latest Shoot football magazine sent over from England by my maternal grandparents.

  Sadly, the library was destroyed. Jiddū’s house was in the centre of Najaf, just two minutes’ walk from the fabulous golden-domed Imam Ali Mosque. In an intriguing parallel (for me
, personally – albeit on a smaller scale) to the fate of the Baghdad House of Wisdom library at the hands of the Mongols in 1258, Saddam Hussein was responsible for the destruction of the ‘House of Jiddū’ library in the early 1990s when the whole neighbourhood was razed to the ground by the Republican Guards’ bulldozers after the Shi’a uprising of March 1991.

  Was my grandfather typical of the sort of physician produced in the Islamic world? What real medical training did he have anyway? And if we project medical knowledge back one thousand years into the past, we might rightly ask just what sort of medicine was being practised in the Abbāsid world. Here, again, we find the standard Western view of the state of medical knowledge in early Islam to be very wide of the mark. The mistake has been to confuse the medical knowledge developed and practised during the golden age of Islam with something referred to as ‘Islamic medicine’. The latter has a quite specific meaning and refers to a tradition of medicine, still practised today, that fuses the teachings of the Qur’an and Hadīth together with Aristotelian philosophy, ancient herbal remedies and dietary advice, all mixed in together with generous dollops of common sense and hocus-pocus. It therefore fits more comfortably into what we would now call complementary holistic medicine rather than medical science proper.

  What I hope to convince you of is that, while these factors certainly played a major part in the medical practices of ninth-, tenth- and eleventh-century Baghdad and elsewhere, many Islamic physicians tried to tackle medicine in a more careful, quantitative and objective way – and none more so than Abū Bakr Muhammad ibn Zakariyya al-Rāzi, who was the greatest physician and clinician of Islam and indeed of the whole Middle Ages. He pioneered so many areas of medical science, from paediatrics to psychiatry, that I could fill a page just listing them. So, like al-Khwārizmi and algebra a generation before him, we should first understand what medical knowledge al-Rāzi inherited.