A major new exhibition draws attention to the achievements of Arab science, the most advanced in the world during its golden age, writes David Tresilian in Paris Eagerly awaited by the French public, L'Age d'or des sciences arabes (The Golden Age of Arab Science) is an exhibition of the science and technology used in the Arab and Muslim world between the 8th and the 15th centuries CE that opened at the Institut du monde arabe in Paris last week. It builds upon a strong record of recent exhibitions at the Institut, whose aim is to make the history, culture and civilisation of the Arab world better known to European and international audiences, and it presents an overview of a subject that has given rise to extensive debate, notably owing to changing appreciations of the role historically played by Arab and Muslim civilisation in the passage from antiquity, as well as to the considerable intrinsic and comparative interest of the material itself. Taking in an area extending from central and south Asia in the east to the Iberian peninsula and present-day Morocco in the west, the exhibition aims to show how the Arab civilisation that united this vast geographical region in the wake of the conquests of the seventh and eighth centuries CE itself built upon the scientific and technological achievements of the earlier civilisations that it either absorbed or with which it came into contact. These civilisations, chiefly Ancient Greek, Roman or Byzantine, and Hellenistic in the Eastern Mediterranean, but also Ancient Persian and Indian further afield, all had their own scientific traditions and technological achievements, and the Arab civilisation that to greater or lesser degrees either absorbed or replaced them took elements from each, in so doing producing its own characteristic science and technology. The first room of the exhibition presents the visitor with a large map of the region concerned, showing the extent of the Arab conquests and signalling the more important urban centres from Samarkand in the east to Fez and Marrakesh in Morocco in the west, together with the cities of Muslim Spain. An accompanying video shows how common cultural features, such as architectural styles, but also of course religion and styles of literary, scientific and musical expression, held this region together, and it also signals the importance of Baghdad, seat of the Abbasid caliphs, as the political, cultural and intellectual centre of this vast ensemble, at least at first. Indeed, it was the Abbasid caliph al-Ma'moun (reigned 813 -- 833) who, tradition has it, inaugurated the translation programme from the Greek that lay behind the Arab appropriation and development of the classical scientific and philosophical heritage. According to a later 10th-century commentator, Ibn al-Nadim in his Fihrist (Catalogue), an account of the books to be found in the Baghdad libraries of the time, Aristotle himself appeared to al-Ma'moun in a dream, encouraging the caliph to undertake this unprecedented translation programme into Arabic as the new lingua franca of the post- classical world and to set up the Bayt al-Hikma, the House of Wisdom, in Baghdad where many of the early scholars worked. The exhibition focusses in large part on the nature of the books translated and the technological, scientific and philosophical knowledge that the Arabs gained from them. Divided into broad sections on astronomy, biology, engineering and the relationship between science, culture and the arts, the visitor is guided through a series of rooms displaying both the applications for which the science of the time was used, such as navigation in the case of astronomy, or medicine and veterinary science in the case of biology, as well as the speculative and philosophical writings developed out of it. Arab mathematics, for example, yielded both techniques for architectural construction drawn from translations of the work of the Greek writers Euclid and Archimedes, as well as more speculative writings on algebra, a word of Arab origin, perhaps developed more in a spirit of pure inquiry. The same would seem to be true of Arab optics and the work carried out by Arab scientists on lenses and on certain qualities of light, such as the calculation of angles of refraction and reflection. Some of this work would have had direct technological applications, while other parts of it would have been carried out in a spirit of intellectual inquiry and as exercises in the use of the experimental method. The exhibition's first section exemplifies this dual emphasis on theory and practice, showing how techniques developed to observe and measure the sky and the earth, giving rise to astronomy and cartography, also led to innovations in mathematics and in thinking about the place of the earth in the universe. Major exhibits here include a series of mostly planespheric astrolabes, instruments used for navigation developed by the Arabs from Hellenistic models, the oldest of which was made in Baghdad and dates to 927- 928 CE. In addition to navigation, the Arabs also used astronomy to resolve problems related to religious practice, such as calculating prayer times and the divisions of the lunar calendar, as well as the direction of Mecca. In order to do so, they took over and developed Greek astronomical practice, as well as elements from ancient Persia and India, including the calculation of astronomical tables. However, as Georges Saliba, an authority in the field, points out in a useful essay in the beautifully illustrated exhibition catalogue, Arab translation and appropriation of the Greek inheritance in this area characteristically involved much larger issues than simply technical ones. In translating the astronomical and cosmological writings of the second-century Hellenistic philosopher Ptolemy, a native of Alexandria, for example, they made a digest of Hellenistic thought and practice available in Arabic, which had now replaced Greek or Latin as the language of education and intellectual inquiry. The resulting book, the Almageste, was known by its Arabic title even in later European Latin translations, and the geocentric model of the universe it presented, with a stationary earth surrounded by a series of celestial spheres and orbited by the sun, defined cosmological thinking until it was overturned by the Polish astronomer Copernicus in the 16th century. Yet, Arab astronomers and scientists did not take the Ptolemaic model on trust, and their criticisms of it bear witness to one of the most important features of Arab science, distinguishing it from the repertory of technical methods available in the Indo-Iranian scientific traditions, and bringing it closer to the philosophically informed science of the Ancient Greeks and Romans. This is so because Arab science also inherited the scientific method from the Greeks, with its emphasis on theory-building and experiment, and when Arab astronomers noted from observations that the stars did not always behave as Ptolemy's model predicted that they should, they began to offer revisions to the Ptolemaic theory in a fashion later extended by Copernicus or Galileo. Indeed, the main curator of the exhibition, Ahmed Djebbar, a French professor of mathematics, has himself earlier written that the emphasis on scientific method, sometimes believed lost until the scientific revolution in 17th-century Europe, was a distinguishing feature of Arab scientific thought. In his Histoire de la science arabe, co-written with Jean Rosmorduc (reviewed in Al-Ahram Weekly in January 2002), for example, he writes that while Ancient Persian, Babylonian and Ancient Egyptian science was "fundamentally empirical in character and designed to solve certain practical problems" only, "the heritage that Arab-Muslim civilisation received from Greek antiquity...[contained] a discourse on science in the work of the Greek philosophers [that] to a large extent dictated Arab procedures." Djebbar also notes that both Al-Bayruni and Ibn al-Haytham in the 11th century had already had "doubts about Ptolemy", the title of a work by the latter writer ( al-shukuk 'ala batlaymus ). While these doubts seem not to have been great enough for either writer to jettison the Ptolemaic model in its entirety, they were important enough to demonstrate that these writers had a conception of scientific knowledge close to Ancient Greek conceptions of rationality. It was this emphasis on method and scientific advance that made the peoples of the Muslim empire established under the Abbasids, in Djebbar's words, "the most 'Greek' peoples after the Greeks themselves". If Arab thinking on astronomical and cosmological matters was dominated by Ptolemy, biology, medicine and pharmacology were carried forward according to an agenda set out by the Roman writer Galen (c.129 -- 199 CE) and the first-century Greek author Dioscorides. This part of the exhibition, mostly consisting of copies of translations from the Greek writers and Arab works building upon them, shows how far Arab medical thinking was indebted to classical ideas of the four humours and to the achievement of a balance between them if health was to be maintained. However, for good health to be assured, or for it to be regained if it had been lost, a wide appreciation of the workings of the body and its relationship to the environment was required, including notions of hygiene, diet, anatomy and therapy, and the exhibition includes examples both of beautifully illustrated translated copies of Dioscorides's pharmaceutical treatise, called Materia medica (Materials of Medicine) in Latin, as well as copies of the summary works on medicine by the 11th and 12th- century Arab philosophers Ibn Sina (Avicenna in Latin) and Ibn Rushd (Averroes), entitled the Qanun fi al-tibb (Canon of Medicine) and the Kitab al-kulliyat fi al-tibb (Collected Works on Medicine), respectively, in 13th-century versions from Spain. Later sections of the exhibition look at engineering, particularly at the contributions made by the so-called Banu Musa, a group of three brothers working in mathematics, hydraulics and the management of water resources in ninth-century Iraq, at the contributions made by mathematical thinking to architectural design and construction, and at the possible relationships, for the peoples of this vast cultural area, between scientific knowledge and the arts. The exhibition also contains a final section displaying some of the designs for the automatons, or "marvels", that apparently diverted the Arab empire's aristocracy and elites. These include various kinds of perpetual motion machines, ingenious designs for hydraulically powered clocks, and designs for automata, robot-like human models, that poured drinks at banquets or performed other similar tricks. Taken as a whole, L'Age d'or des sciences arabes does a remarkably successful job in showing the range and implications of the Arab scientific thought and technical achievements of the period, and the copies of scientific texts on display, drawn from museums and collections the world over, are often fascinating and beautiful to look at. However, the fact that no material is available in any language other than French may be a problem for some visitors. While one would not want the exhibition itself to be cluttered up with English-language material, given restrictions on space, it might have been an idea to produce the catalogue in English or Arabic versions, or at least to provide an Arabic or English summary of it. Finally, the exhibition does not address what a recent author has described as "the problem of Arab science". According to T E Huff in his The Rise of Early Modern Science (Cambridge: 1993), "from the eighth century to the end of the fourteenth, Arabic science was probably the most advanced in the world, greatly surpassing the West and China. In virtually every field of endeavour -- in astronomy, alchemy, mathematics, medicine, optics -- Arab scientists were in the forefront of scientific advance." Why, then, did this science not "culminate in a scientific revolution.... [and] the birth of modern science"? It seems a pity that this exhibition does not address this question, though Jean Audouze's final catalogue entry, "The Place of Arab Science in History", does gesture towards it. For a sensitive consideration of the issues one might do worse than turn to Ahmed Djebbar's own discussion in his Histoire de la science arabe. L'Age d'or des sciences arabes, Institut du monde arabe, Paris, until 19 March 2006. The catalogue of the exhibition is published jointly by Actes sud and the Institut du monde arabe.
