I have written some essays on Islam and science before, but I will expand on them further here. Here, I will concentrate mainly on the medical traditions in the Middle East and Europe because those are the ones I have sufficient knowledge about.

Rhazes (Al-Razi) lived from 865 to 925 and was the author of numerous treatises on medicine. He expressed some doubts about the leading Greek physician Galen, but at the same time considered himself Galen's disciple. He was among the first to describe the differences between smallpox and measles and was definitely one of the leading physicians in the history of the Islamic world, but it is doubtful whether we can call him a Muslim.

As Ibn Warraq writes in his modern classic Why I Am Not a Muslim, "Perhaps the greatest freethinker in the whole of Islam was al-Razi, the Rhazes of Medieval Europe (or Razis of Chaucer), where his prestige and authority remained unchallenged until the seventeenth century. Meyerhof also calls him the 'greatest physician of the Islamic world and one of the great physicians of all time.'" He was also highly critical of Islamic doctrines, and considered the Koran to be an assorted mixture of "absurd and inconsistent fables." Moreover, "His heretical writings, significantly, have not survived and were not widely read; nonetheless, they are witness to a remarkably tolerant culture and society – a tolerance lacking in other periods and places."

Avicenna (Ibn Sina) was a talented Persian physician who continued the course set by Rhazes of mixing Indian, East Asian and Middle Eastern medical learning, but he relied heavily on Greek medicine, just like Rhazes did. A striking number of the Muslims who did leave some imprint upon the history of science were Persians. Avicenna based much of his research on the legacies of Hippocrates and Galen, as well as the Alexandrine schools and earlier Islamic physicians. His book The Canon of Medicine (Kitab al-Qanun) from the early eleventh century was a standard medical text for centuries, not only in the Middle East but also in Europe and in some regions of India under Islamic rule. It contained descriptions of the effects of various diseases as well as descriptions of hundreds of drugs for treatment. Avicenna was involved in many subjects besides medicine, was skeptical about alchemy (which was an unpopular viewpoint at the time) and did significant work on motion.

The issue of science in the Islamic world has become a topic of political controversy. Former French President Jacques Chirac has stated that European civilization is as indebted to Islam as it is to Christianity. In response to such ideas, the Frenchman Sylvain Gouguenheim, professor of medieval history at the university l'École Normale Supérieure de Lyon, has written a book attacking the "thesis of the West's debt to Islam" as advanced by Edward Said, Alain de Libera and Mohammed Arkoun, among others.

He upgrades the Byzantine contribution to the preservation of learning, which is often slighted today, and calls the Mont Saint-Michel monastery, where many texts were translated into Latin, "the missing link in the passage from the Greek to the Latin world of Aristotelian philosophy." Apart from a small number of thinkers – he mentions Al-Farabi, Avicenna, Abu Ma'shar and Averroes – Sylvain Gouguenheim believes Muslims retained from Greek teaching only what didn't contradict Koranic doctrine. Europeans, he said, "became aware of the Greek texts because it went hunting for them, not because they were brought to them."

Personally, I wouldn't say that the impact of the translation movement from Arabic was zero. It is vastly overrated, but I don't think you can write European history if you ignore it entirely. The medical texts of Avicenna and Rhazes were used for several centuries. Although most of the Greek texts available in Arabic were based on Byzantine originals, and Western Europeans later translated directly from Byzantine manuscripts, some of the medical texts incorporated contributions from the Middle East, India and other regions of Asia that were not included in the Greek texts. Yet the Islamic world made very few advances after the first few centuries, when the non-Muslim population declined, and even the initial advances they did make are often exaggerated.

I mentioned to Dr. Andrew G. Bostom that I was writing about medicine and science in the Islamic medieval world. He is the author of the excellent book The Legacy of Jihad as well as the upcoming The Legacy of Islamic Antisemitism, which I hope to publish a review of in a few weeks.

Mr. Bostom is a medical doctor by profession, and argues that "Avicenna and Rhazes made arguably no more contributions than their non-Muslim peers, and moreover were marginal Muslims." According to him, the origins of modern science, as an organized, empirically directed effort to explain natural phenomena through theory construction and testing, were undeniably European. He quotes Edward Grant in The Foundations of Modern Science in the Middle Ages as saying that "it is indisputable that modern science emerged in the seventeenth century in Western Europe and nowhere else."

Rhazes wasn't a Muslim in anything but the name, and Avicenna at best an unorthodox one, that's true, but the Flemish physician Andreas Vesalius (1514-1564) wrote a thesis based on Rhazes as late as the sixteenth century. Of course, the advances made in anatomy that he and others did in Europe were specifically blocked by Islam. It is surprisingly difficult to define the specific advances in medicine made by Muslim physicians. The only tangible advance I have found so far is regarding the circulation of the blood. I don't always agree with historian Bernard Lewis, but here is how he describes the discovery of the circulation of the blood in his book What Went Wrong?: The Clash Between Islam and Modernity in the Middle East:

"In Western histories of science, this is normally credited to the English physician William Harvey, whose epoch-making Essay on the Motion of the Heart and Blood was published in 1628 and transformed both the theory and practice of medicine. His great discovery was preceded and helped by the work of a Spanish physician and theologian, Miguel Serveto, usually known as Michael Servetus (1511-1553), who owes his place in scientific history to the discovery, published in 1553, of the lesser or pulmonary circulation of the blood. This discovery was anticipated, in surprisingly similar detail, by a thirteenth-century Syrian physician called Ibn al-Nafis. Among his writings was a medical treatise in which, in defiance of the revered authority of Galen and Avicenna, he set forth his theory of the circulation of the blood in terms very similar to those later used by Servetus and adopted by Harvey, but unlike theirs, based on abstract reasoning rather than experiment. Modern orientalist scholarship has shown, with a high degree of probability, that Servetus knew of the work of Ibn al-Nafis, thanks to a Renaissance scholar called Andrea Alpago (died ca. 1520) who spent many years in Syria collecting and translating Arabic medical manuscripts."

Ibn a-Nafis was apparently successful and died a wealthy man at the age of about 80, leaving his library to a Cairo hospital, but still: "His book and his theory remained unknown and had no effect of the practice of medicine. Servetus was arrested in Geneva on August 14, 1553, and charged with blasphemy and heresy. The Protestant authorities, and notably Calvin, demanded that he retract his religious opinions or face the consequences. Servetus refused; he was condemned on October 26, 1553, and burned next day as a heretic. His medical work remained, and formed the basis of major scientific advances in the years that followed."

What is difficult to explain is why al-Nafis died successful and wealthy in an important city in the Islamic world, yet his work was not followed up by other Muslims. He is by no means the only example of this cultural failure. Servetus was executed, yet even his work was continued in Europe. The Islamic world took little care of the few genuine talents it did produce.

In A Brief History of Disease, Science and Medicine, Michael Kennedy takes a look at the discovery of the pulmonary circulation of the blood, and credits Ibn al-Nafis with the first known description of this. His work was supposedly "discovered by Spanish physician and scholar Michael Servetus (1511-1553) and transmitted by him to Realdo Colombo, a professor of anatomy at Padua, who is usually credited with the concept." Servetus, also known as Miguel Serveto, "probably learned of al-Nafis through the writings of a Syrian scholar and translator of Arabic works named Andrea Alpago, who died about 1520."

Yet according to Kennedy, "Al-Nafis' writings had no effect on science (other than through Servetus) and were only discovered in 1924. They exist as an example of what might have been in the world of Islam. Other than al-Nafis, Arabic medicine contributed little original, being based on the Greek models, but they made huge contributions in pharmacology, discovering and cataloging thousands of new drugs. The word 'drug' is Arabic as are alcohol, alkali, syrup, jujube, and spinach. New drugs introduced by Arabs include benzoin, camphor, myrrh, musk, laudanum (the alcohol solution of opium), naphtha, senna, and alcohol itself. Both al-Razi and Avicenna emphasized reason and suggested that mineral or chemical remedies would be superior to the magical potions and herbs of folk medicine. The great value of Arab contributions to medicine lies in the thoroughness of their preservation and systematic organization of knowledge. Aside from pharmacology, they contributed little that was new and the influence of Avicenna, like that of Aristotle, finally became a barrier to new learning."

I take issue with the term "Arabic" here and would prefer "Middle Eastern," as many of the leading individuals were Persians, most of the translators were Christian or Jews and the works that were used were of Greek, Indian or other pre-Islamic origins. Kennedy mentions that resistance to new learning was enhanced by the negative concept of imitating the infidel. Moreover, bidaa (innovation) has very negative connotations, close to heresy. There was also powerful religious resistance to the adoption of printing.

Razi, or Rhazes, was a committed alchemist and allegedly made an attempt to demonstrate to a Muslim Emir how he could turn base metal into gold. When this failed, he was beaten over the head with his own book.

According to Kennedy, "His great book was translated into Latin in 1279 as Liber Continens and became a reference work in the West for centuries. No copy of his work survives in Arabic, a commentary on the decline to come." Among his achievements, "Al-Razi described the glassware and instruments of alchemy, which would remain the standard equipment of chemists until the nineteenth century. He described the processes of distillation, sublimation (solid to vapor), calcination (powdering of solids), and solution. He classified substances and was the first to use the categories of animal, vegetable, and mineral in describing matter. He described the use of sal ammoniac (ammonium chloride) and conducted sophisticated experiments, which have been duplicated in modern times so thorough are his descriptions."

As indicated above, one possible advance made by Muslims in this age could ironically be the creation of distilled alcohol. Some forms of primitive distillation may have existed in India, China, the Middle East and Egypt in ancient times, and was later practiced among Greek alchemists in Alexandria. Nevertheless, the modern distillation of pure or nearly pure alcohol (ethanol) appears to have been a product of medieval times, spreading west, but perhaps also east through Central Asia. A number of persons in the Middle East did at the very least contribute to the dissemination of this idea, if not to its creation. It was mentioned in the writings of Rhazes, whose work was later introduced to Europe during the High Middle Ages.

Beverages containing distilled alcohol made their first appearance among alchemists at about this time. They were primarily interested in medical "elixirs," but it is significant that the first "brandies" or spirits for non-medical purposes, such as whiskey, vodka and cognac, were all invented in Europe during late medieval or early modern times.

In A History of Beer and Brewing, I. Hornsey explains how the use of filamentous fungi for alcoholic fermentation was employed in East Asia: "The koji process was developed centuries ago in the Far East and, nowadays, is predominantly a starter culture and a source of enzymes for the saccharification of rice starch in the brewing of saki. Thus, in this process, koji performs the same function as malted barley does in a Western brewing regime."

Hornsey claims that commercial sake is pasteurised. It is interesting to notice that "a pasteurisation technique was first mentioned in 1568 in the Tamonin-nikki, the diary of a Buddhist monk, indicating that it was practised in Japan some 300 years before Pasteur."

China appears to have been the first country to develop anything resembling pasteurisation, in medieval times. The beverages were heated, but the resulting "pasteurized" drink was then put back into bacteria infected containers. The process was thus not fully developed or understood at the time. It could not be so until the invention of the microscope and the development of microbiology. The latter happened in Europe in the nineteenth under the leadership of individuals such as Louis Pasteur.

In The Gifts of Athena: Historical Origins of the Knowledge Economy, Joel Mokyr explains that prior to the Industrial Revolution, innovation was not sustained over long periods of time. When new techniques came around, often important ones, they usually crystallized at a new technological plateau and did not lead to a stream of cumulative microinventions. As he says:

"In both Europe and China, techniques worked despite a lack of understanding of why they worked. Normally, it was enough if someone recognized some exploitable regularity. Whether we look at steelmaking, cattle-breeding, or obstetric surgery, most techniques before 1800 emerged as a result of chance discoveries, trial and error, or good mechanical intuition and often worked quite well despite nobody's having much of a clue as to the principles at work."

Mokyr explains further: "For example, if a manufacturer does not know the nature of the fermentation that turns sugar into alcohol, he or she can still brew beer and make wine, but will have only a limited ability to perfect their flavor or to mass produce at low prices. When no one knows why things work, potential inventors do not know what will not work and will waste valuable resources in fruitless searches for things that cannot be made, such as perpetual-motion machines or gold from base metals. The range of experimentation possibilities that needs to be searched over is far larger if the searcher knows nothing about the natural principles at work. To paraphrase Pasteur's famous aphorism once more, fortune may sometimes favor unprepared minds, but only for a short while."

Pasteur explained not just that the process now known as pasteurization works, but why, which is why it should be properly named after him. The distinction is not trivial, since the establishment of microbiology created modern medicine as we know it, and led to making the European medical tradition into the global medical tradition.

According to I. Hornsey, "Japanese saki is closely related to the Chinese rice wine, shaosing chu, but it is clear, pale yellow, and slightly sweet, whereas shaosing chu has a deeper colour and is much sharper, due to natural oxidation. The normal alcoholic content of saki is around 15%, although it can reach 20%."

The creation of alcoholic beverages such as wine, beer or mead has been done on all continents for thousands of years, but through such "natural" processes, the maximum alcohol content rarely exceeded 15% - 20%. This changed about one thousand years ago. In the Cambridge World History of Food, James Comer writes about distilled beverages:

"Alcoholic beverages have been a part of human culture since at least the Neolithic period. Yet until recently, beverages made from fruits, grains, or honey were considered to be what historian Wolfgang Schivelbusch (1992) has called 'organic,' meaning that the amount of sugar in the ingredients produced the amount of alcohol in the drinks. Examples of such beverages are beer and wine. Beginning in the period from about A.D. 800 to 1300, however, people in China and the West learned to distill alcoholic liquids."

As he explains, "Distillation is a method for increasing the alcohol content (and, thus, the potency) of a liquid already containing alcohol - the existing alcohol content usually the result of the fermentation of vegetable sugars. The distillation process separates the alcohol from other parts of the solution by the heating of the liquid to 173° Fahrenheit [78° Celsius], a temperature sufficient to boil alcohol but not water. The resulting steam (vaporized alcohol) is collected and condensed, returning it to liquid form – but a liquid with a much higher proportion of alcohol than before. Repeating the process increases the liquor's potency yet further."

The basic tools for this process were known in Antiquity, but were developed further during the Middle Ages, first in the Islamic world and later in Europe:

"Stills are the traditional equipment needed to destill alcohol. There are many different types. The earliest known is the ambix (plural ambices) used by Greek alchemists. Ambices were ceramic or metal pots with heads shaped so that liquid would condense inside the head and drain out through a collecting tube. Later, during the Middle Ages, Muslim alchemists, who also employed the ambix, added the Arabic article al- to its name, hence the term 'alembic' for a still (Forbes 1948). When larger amounts of alcohol began to be destilled in the fifteenth and sixteenth centuries, the ambix was improved, giving rise to several types of stills."

Several leading alchemists experimented with distillation. They believed that they had extracted the "essence" or "spirit" of wine and that repeated distillations resulted in aqua vitae – the "water of life." This substance was mostly used as a medicine. Tea in China and later chocolate when it was first imported from pre-Columbian Mesoamerica to Europe (see my essay A History of Cacao and Chocolate) were initially used as medicine, too, but distilled alcohol is still used for medical purposes in the twenty-first century.

According to Comer, "both the Irish and the Scots claim to have produced liquor from grain (in contrast to brandy from wine) since the beginning of the last millennium; the Scots called it uisge beatha (pronounced wisky-baw) and the Irish called it uisce beatha. Both meant 'water of life,' and the English term 'whiskey' derived from them."

The question of Ireland and Scotland is somewhat controversial. Whiskey was definitely known in both countries in the fifteenth century, probably several centuries before. There are those who claim that distillation was invented independently on the British Isles and that it predates the improvements of distillation in the Middle East, but there is so far little evidence for this. In medieval times, the processes of aging and the separation of the different fractions of the distillate were unknown. Because distilled alcohol contains bad-tasting and dangerous chemicals, it is often aged in a procedure, originating in the eighteenth century, that rids the beverage of these chemicals. As the liquid ages, its container (preferably made of wood) colors and flavors it to produce a smoother and better-tasting product.

The first real brandy that was not thought of as medicine is said to have been distilled in 1300 by Arnaldus de Villa Nova, a professor at the medical school of Montpelier. During the fifteenth century, better methods for cooling the still's head developed. This led to increased production of distilled beverages, which spread rapidly across Europe in various forms and names. France became an important center of the expanding brandy industry, especially the region surrounding the town of Cognac.

According to James Comer, "Paracelsus (Philippus Aureolus) had employed the Arabic term alcool vini to describe spirits. But it was not until 1730, when the Dutch physician Herman Boerhave used the word alcohol to mean distilled spirits, that it became commonly understood that ale, wine and distilled beverages all owed their mood-altering capabilities to this chemical."

A constant theme in the discussion of brandy was fire, because beverages are "burnt" or distilled over the flame of a still, because distilled alcohol is capable of combustion, and because of the "burning" sensation experienced by those who drink it. Comer again:

"First called 'brandy wine' (from the Dutch brandewijn), brandy means 'to burn' or 'burnt' in Dutch as well as in other languages, such as the German Brand and the Middle English 'brand.' Brandy is more expensive to make than grain spirits because it must be distilled from fruit and, in the case of cognac, from wine (Ray 1974). As noted, brandy first emerged as medicine in the eleventh century and only later became popular as a beverage."

That was the story of distilled alcohol. Back to the history of mainstream medicine. Abu al-Qasim Khalaf ibn al-Abbas al-Zahrawi, known in the West as Albucasis, was born in 936 in Cordoba in Spain. He described many surgical instruments, some of which he designed. Yet he is virtually the only significant physician in the Islamic world who had practical experience with surgery. Surgery was widely neglected by Middle Easterners at this time, also by Rhazes and Avicenna. According to Michael Kennedy, "These two bodies of work, that of al-Razi and that of Avicenna, dominated medicine and science until almost modern times. Neither reached beyond Galen in theory."

The Greek physician Galen worked in the Roman Empire during the second century A.D. He produced an enormous body of writings, summing up the medical knowledge of the Mediterranean world at the time, and later became regarded as the leading medical authority of Greco-Roman Antiquity, rivalled only by Hippocrates. He was deeply influenced by the Hippocratic corpus.

In his book The Beginnings of Western Science: The European Scientific Tradition in Philosophical, Religious, and Institutional Context, Prehistory to A.D. 1450, second edition, David C. Lindberg states the following:

"Galen studied medicine in Pergamum and Smyrna (both in Asia Minor), then in Corinth on the Greek mainland, and finally in Alexandria. From Alexandria, he returned to Pergamum as physician to the gladiators, then moved to Rome in search of patronage, returned to Pergamum, went back to Italy, and eventually settled in Rome, where he enjoyed the friendship and served the medical needs of the rich and powerful, including the emperors Marcus Aurelius, Commodus, and Septimius Severus. He died after 210."

The dissection of human corpses was taboo in ancient times. Galen lamented this, but based his studies of anatomy on dissections of animals such as monkeys, pigs and dogs. This is funny if you are familiar with the low status these animals have in Islam, and know that subsequent medicine in the Muslim world was inspired by Galen. Since Jews are "sons of monkeys and pigs" in the Koran, does that mean that "Islamic medicine" was based on Jew anatomy?

Toby E. Huff, author of the excellent book The Rise of Early Modern Science: Islam, China and the West, takes a look at the development of science. A landmark in Western science was Nicholas Copernicus' The Revolutions of the Heavenly Spheres from 1543. The same years also saw another milestone in the rise of modern science: Vesalius' On the Fabric of the Human Body, which created the foundations for modern medicine by representing an empirical agenda, the first-hand examination of the body through human dissection (autopsy).

According to Huff, "Vesalius claimed to have corrected over 200 errors in Galen's account of human anatomy," and his "illustrations are far superior to anything to be found in the Arabic/Islamic tradition (where pictorial representation of the human body was particularly suspect) or, for that matter, in the Chinese and (I presume) Indian traditions."

The Syrian Ibn al-Nafis, who worked in hospitals in Damascus and Cairo in the thirteenth century, was a capable physician. However, according to Huff, "al-Nafis tells us that he avoided the practice of dissection because of the shari'a [the religious law] and his own 'compassion' for the human body. He also says that, 'we will rely on the forms of the internal parts [of the human body] on the discussion of our predecessors among those who practiced this art [of dissection], especially the excellent Galen, since his books are the best of the books on this topic which have reached us.' Ibn al-Nafis, it should be noted, was also a specialist in Islamic jurisprudence, so that his construal of the practice of dissection as un-Islamic carries special weight."

During the High Middle Ages and the Renaissance, the knowledge of medicine improved in Europe, thanks to the medical institutes at the rapidly expanding number of universities, where dissections of human corpses were sometimes performed to train students. Dissections of pigs, which are anatomically similar to humans, were also performed. As Huff says:

"In short, by the thirteenth century there was no major ideological resistance to the performing of human dissections in Europe. At the time of Ibn al-Nafis, European anatomists were practicing dissections on the pig and also the human body. Consequently, they had a considerable stock of empirical knowledge about human anatomy that was not available in the Arab-Muslim world. Inspired by the pursuit of scientific knowledge, European physicians engaged in a variety of practices that would have been forbidden in a Muslim context. These included (1) the dissection of human bodies, (2) the dissection of a pig, (3) the performance of the operation in a public forum, and (4) the publication of richly detailed drawings of the human anatomy in all of its minute, and many would say, offensive detail. In contrast to the European practice, Muslims had a religiously conditioned aversion to pigs and their dissection. In addition, Middle Eastern medical education of the time was still based mainly on the memorization of authoritative texts."

According to Michael Kennedy: "Surgery was unchanged by the new developments in anatomy because, with the absence of anesthesia, operations were largely limited to the surface of the body and to amputations. Neither of these fields required details of internal anatomy or physiology."

It is correct that the improvements in the understanding of human anatomy during the Renaissance and the sixteenth century didn't trigger any immediate medical revolution, but they did lead to significant, if gradual, improvements and paved the way for the even greater changes that took place in the Western medical tradition later. The true revolution happened in the nineteenth century, when efficient methods of anesthesia were adopted and the germ theory of disease was decisively proven. The crucial step towards a realistic understanding of cells and nerves as well as microorganisms such as bacteria was achieved in Europe because Europe was the first civilization to invent the microscope as well as the scientific method. Ironically, the Islamic world gave birth to one of the greatest of medieval scientists, Alhazen, who was the world's leading expert on the optical sciences during his time, but his work received little follow-up by fellow Muslims, and further scientific progress was blocked, frequently due to Islamic religious resistance.