Common misperceptions about the history of medicine include the belief that it was mostly guesswork until the past few hundred years. Mental images of charlatan medical “experts” selling their phony cure-alls come to mind when thinking about medicine before the 20th century. In actuality, however, there exists a long medical tradition in the Muslim world based on earlier professionalism. While this is lost in the modern popular imagination, there still exist writings from some of the greatest medical minds the world has ever known who lived and practised in the Muslim Golden Age. Their work points to an era of medical enlightenment and advancement that forms the basis of modern medicine.

Muslim advances in medicine picked up where the ancient Greek physician, Galen, left off. Galen was the giant of this field in ancient times. This second-century CE physician and philosopher wrote extensively on medicine, and supported the theory that the body is composed of four humours: blood, black bile, yellow bile, and phlegm. According to him, diseases were caused by an imbalance of these fluids in the body. Although some of his ideas were revolutionary in his time, others were seriously flawed. Despite this, he was uncritically accepted by physicians for hundreds of years after his death.

The first to critically challenge the ideas of Galen was Muhammad ibn Zakariya al-Razi, who lived in the ninth century. Based in Baghdad, he was a strong proponent of a rational, instead of theoretical understanding of the human body. In his bluntly titled Doubts About Galen, he concluded that physical ailments could not simply be attributed to an imbalance among the humours or to punishment from god as Middle Age Europeans believed, but to certain external and internal factors that must be resolved in order to treat the problem. Along these lines, he developed specific and effective cures for common problems such as coughs, headaches, and constipation. But he was not limited to simply treating the symptoms or physical causes of ailments. His giant medical encyclopaedia, The Virtuous Life, extolls the importance of dedication to the field of medicine and constant improvement and learning.

Furthermore, he believed that medical practice is a sacred endeavour, and that doctors are entrusted by god to do good to anyone who requires it, even their enemies or those who cannot afford medical attention. He was thus known for treating poor patients free of charge in Baghdad’s famous hospitals. His works were widely disseminated, and helped guide future generations of physicians in the Muslim world and Europe for centuries.

The next great Muslim physician, and perhaps the most well-known, was Ibn Sina, known as Avicenna in Medieval Europe. Despite constantly moving from city to city in the turbulent political environment of Persia in the early 1000s, he managed to have one of the most accomplished careers of any polymath of the Muslim Golden Age. He applied the rational approach to science that Muslims were taking in other fields to medicine, giving him insight that others, including al-Razi, lacked. He formulated a theory that everything in the body can be understood through a causal chain of events. While this may seem like common sense in today’s scientifically advanced world, it was a new idea in the early 11th century; one that Ibn Sina was keen to prove.

Based on years of clinical observation and scientific study, he concluded that diseases can be spread through air, water or soil. Furthermore, each disease had unique characteristics and thus must be treated in a unique way. He was one of the first to promote experimental medicine, and in his monumental work, The Canon of Medicine, he insisted that drugs be tested under controlled conditions and not be trusted simply based on theory. Drugs that were not universally effective, or could not be proven to actually treat a disease meant nothing to him, as he believed medicine was a science of observation and rationalism, not mysticism and luck. His Canon became the standard textbook for anyone desiring to learn about medicine in the Muslim world and beyond. European medical schools relied on Latin translations of it into the 17th century, and, in the Yuan Dynasty (13th- and 14th-century), it was translated into Chinese by the sizeable Muslim community in China. It is easy to understand why the Canon enjoyed such widespread popularity and reverence. Ibn Sina’s greatest work was not simply a handbook of common ailments and cures. It was a complete medical encyclopedia. Descriptions can be found in it of anesthesia, breast cancer, rabies, toxins, ulcers, kidney disease, and tuberculosis. Beyond this, Ibn Sina wrote about the connection between mental and physical health, and concluded that negative thoughts can cause illness just as much as other factors such as toxins, injury, or diet.

Today the possibility of a connection between mind and body is attributed to the first generation of psychologists like Freud and Jung. In reality, it was a possibility that seemed very real to Ibn Sina and other physicians and philosophers of his time.

The greatest medical minds of all time would not have been able to accomplish great feats without the support of great institutions. The Muslim world of the Golden Ages, with its vast financial resources and strong political institutions, established some of the first hospitals in history. The impetus to build hospitals came from the need to care for the health of poorer citizens. The wealthy were able to hire private physicians and pay for home treatment, but the poor had no such luxury. To provide for them, caliphs and emirs established large institutions in the great cities of the Muslim world aimed at providing affordable or free healthcare to anyone who would need it. In the early ninth century, the first hospitals began to appear in Baghdad. As the hospitals grew over time, they began to resemble modern hospitals in size and scope. Hospitals had dozens of doctors and nurses, including specialists and surgeons. They contained outpatient centers, psychiatric wards, surgery centers, and maternity wards. Perhaps the biggest difference was that the hospitals of that era were free to those who could not afford it; a far cry from the revenue-fueled hospitals of today. To the patrons of these hospitals, the Prophetic example of compassion was clear. In their eyes, a society based on Islam was expected to care for all its citizens regardless of wealth, race, or even religion. After first being established in Baghdad, these enlightened institutions of healing spread to the rest of the Muslim world’s major cities throughout the tenth to 14th centuries. Hospitals could be found in Cairo, Damascus, Baghdad, Mecca, Medina, and even distant Granada in Iberia.

The Ottomans would later carry on this tradition of public hospitals, and it was during their long reign that Europe would begin to catch up, and even surpass, the Muslim world. The Renaissance saw a move to translate hundreds of Arabic texts into Latin in the great cultural and scientific centers such as Padua and Bologna. Europeans were able to further advance the knowledge of giants such as al-Razi and Ibn Sina, who advanced the knowledge of Galen and Hippocrates. Today’s medical knowledge and institutions come largely from the West, but are based on the earlier Muslim medical tradition, which in turn was based on ancient Greece. The clash of civilisations narrative that is promoted by extremists on both sides of modern conflicts neglects examples of cross-cultural intellectual traditions such as this.

Excerpted with permission from Lost Islamic History: Reclaiming Muslim Civilisation from the Past, Firas Al-Khateeb, Westland Books.