|” The history of the word ‘zero’ is an informative tale.The Arabs borrowed their numerical system – which is far better adapted to arithmetic than the Roman system – from ancient India. When they did so, they named the ‘0’ al-sifr, literally ‘void’. The Arabic word was Latinised as cephirum and cifra, which in Italy was deformed to zefero, and then zero. It is the latter which passed into English and French as the name for the symbol indicating the absence of quantity or magnitude. At the same time, French borrowed the Medieval Latin word cifra, transforming it into chiffre (‘number’), to designate numerical characters in general. It is from this same origin that English derived the word ‘cipher’, originally designating both ‘nought’ and ‘[any] Arabic numeral’, before taking on its present-day meaning of ‘code’ (from the technique of transposing letters according to a numerical key).The history of mathematics is full of Arab inventions. The word ‘algorithm’, for example, comes from the name of the great mathematician Al-Khawarizmi, who is the father of algebra – another Arabic word, coming from the title of Al-Khawarizmi’s work Kitab Al-Jabr (from jabara, ‘to set bones’). The Arabs are also ultimately responsible for the fact that mathematicians the world over today use the letter ‘x’ to designate the unknown quantity – ‘x’ being the first letter of the Spanish word xay, which is a deformation of the Arabic shay, meaning simply ‘thing’.
In the golden age of Arab science, mathematical research was frequently carried out by great polymaths such as the poet Omar Khayyam, who in addition to penning his famous Quatrains also proposed solutions for equations of the third degree. But such research generally had a practical end in mind, such as calculating surface areas in order to assist in urban planning, for example.
The study of astronomy was likewise encouraged with a view to practical ends, and more specifically with a view to predicting the future. On the basis of ancient Persian astrology, numerous Arab-Islamic scholars established longitudes, reformed the calendar, and went against Ptolemy’s teachings by building a planetary model centred on the sun. Much later, Copernicus was in part inspired by their writings.
AIn the Middle Ages, the Arabs, having conserved the science of Antiquity and the teachings of Hippocrates and Galen, were the pioneers of medical research. In particular, they took up the theory of humours, according to which illness is the result of imbalances between four bodily fluids – blood, phlegm, yellow bile (or choler) and black bile (or melancholy) – which govern the body and the personality. Treatments prescribed under this system aimed to re-establish the initial balance, through medication and diet.Arab doctors developed these teachings, leaning on a logical conception of ailments and a methodical approach. Thus they listed and described symptoms, improved the art of diagnosis and clinical practice, and laid down the basis of a professional code of conduct.Their contributions to medical science were legion, encouraged by the construction of hospitals (in Baghdad, Cairo, Damascus, Samarkand and elsewhere), each under the command of a master. The basic principles of hygiene (asepsis, and the isolation of contagious cases) were discovered, at a time when Europe believed that leprosy and the plague could be transmitted by sight, and a very wide range of medications was developed thanks in part to wide-ranging international trade, be it by caravan or by sea. Countless plants, animal extracts and minerals were used in plasters, unguents, cataplasms and tablets.
Avicenna’s famous Canon (or Qanun) was a monumental medical encyclopaedia, which presented and categorised almost 800 remedies. European medical vocabulary to this day bears traces of the pharmacological inventiveness of the Arabs, in the form of words with Arabic etymologies such as ‘alcohol’, ‘benzine’, ‘benjoin’, ‘elixir’, ‘soda’, ‘talc’, ‘amber’, ‘senna’ and so on.
Avicenna (the Latinised form of the Arabic name Ibn Sina) was of course the outstanding figure in medieval Arab medicine. Born in 980 CE, Avicenna began to practice medicine at the age of 16. It is to him that we owe the first descriptions of meningitis and pleurisy, as well as over 100 medical and philosophical works.
His Canon was translated into Latin and published in Europe for the first time in 1473. Less than a hundred years later, it had already run to 36 editions.
In the fields of optics and mechanics, the Arabs did not merely content themselves with preserving the heritage of Antiquity – they pushed beyond its limits, inventing astonishing automata and precious new techniques (notably for agricultural purposes, such as presses for olives and sugar cane, or the bucket waterwheel). Al-Jazari built a monumental clock, in which moving circles represented the movement of the zodiac, the sun and the moon, while mechanical birds dropped marbles onto cymbals to strike the hour and animated figurines played drums and other instruments.Arab alchemists, meanwhile, managed to create new substances (acids, alcohols, etc.). Starting out from the quest for the ‘philosopher’s stone’ that would turn base metals into gold, some of them ended up turning their backs on magic altogether, preferring to concentrate on pure experimentation.
“It is inconceivable that God could have singled out certain men that they should prevail over the mass of their fellows.” – Al-Razi.The Arab passion for books and the great wave of translation (from Greek to Syriac, and then to Arabic) effectively saved works by Aristotle, Plato and others from being lost to humanity. Public libraries became commonplace (there were more than 100 in Baghdad by the year 900 CE). The library of Cairo contained some 1,600,000 volumes. The passion for ideas was a distinguishing mark of men of quality. Inevitably, therefore, in a society structured by the precepts and practices of Islam, the question of the relationship between reason and faith was posed.The most radical position was adopted by Al-Razi (d. 925), who rejected all revealed religions en bloc, along with miracles. His atheism was based on a progressive conception of knowledge as both provisional and perfectible.
But for most medieval Arab thinkers, Islam remained the anchor of their falsafa (philosophy). A commonly adopted principle was that truth is one and indivisible, be it revealed or obtained by reason, and no matter whether it was of Arab or non-Arab origin. This was the thesis of Al-Kindi (d. 873), traditionally honoured as the “philosopher of the Arabs”, who in the end gave divine knowledge the benefit of the doubt and became a mystic. After him, Farabi (d. 950) wrote numerous commentaries which tried to demonstrate the compatibility of the writings of Plato and Aristotle with Islamic thought. His “model city” is effectively an adaptation of Plato’s Republic.
However, philosophical thought touched on such delicate topics as the oneness of creation or the survival of the body and/or the soul after death, and any reference to “Arab science” remained, for most believers, dangerously innovative and suspiciously close to heresy.
The counter-attack against the Arab philosophers was led by Al-Ghazali (d. 1111 CE). He condemned the impurity of their ideas (for example their denial that the world was created and would come to an end, or that the bodies of believers would be resurrected). Al-Ghazali underlined the importance of sciences that are useful to the community, but his distinction between religious and non-religious (ghayr shar’iyya) sciences pushed philosophy out to the farthest margins of what was religiously acceptable.
There was to be no real riposte to Al-Ghazali until a century later, when Ibn Rushd argued in favour of the compatibility of Qur’anic doctrine and the philosophical enterprise, and, above all, in favour of the right to use one’s reason to its fullest extent.
Ibn Rushd (whose name was Latinised as Averroes) no doubt left a more profound mark on human thought than any other Andalusian. A doctor, an administrator and an astronomer as well as a philosopher, Averroes built up an enormous reputation in both the Arab world and Christendom. Anecdotes about his life present him as an archetypal atheist, but his works are more concerned with reconciling faith and reason. His commentaries on Aristotle express the need for incredulity as well as the diversity of ways of expressing the truth.
Averroes exerted a deep influence on medieval scholasticism. But his works could hardly satisfy Christian theologians such as St Thomas Aquinas, who were ill disposed to consider philosophy as an independent discipline. The Arabs had already burnt Averroes’ books; the Christians followed suit, and philosophy was subjugated.