medicine, factors of development

The causes of change and continuity in medicine are key to the understanding of the history of medicine. Factors to be taken into consideration include government, religion, war, science and technology, communications, individuals, conservatism, and chance. It is the interaction, or coming together, of two or more of these factors that effects the advance, stagnation, or even reversal of medical knowledge and practice.

Government The role of governments in medicine has often been key to either progress or regress. A strong central government such as that of the Roman Empire can ensure that there is the stability and money needed for medicine to develop. Governments make decisions on how to spend money; for instance, the US government funded the research of Howard Florey and Ernst Chain into penicillin during World War II. Governments have influenced the history of public health, either through inaction, as in the UK in the 19th century, or positive action, as in the UK in the 20th century. The decisions of governments are often crucial to medicine. Controversial technologies such as genetic engineering and human cloning are regulated by government rulings.

Religion The beliefs and practices of religion have influenced medicine throughout history. The first doctors were prehistoric priests and medicine men. Medical knowledge can advance because of religion. The Egyptians discovered much about human anatomy because they practiced mummification as part of their funerary rites. The Christian church preserved medical knowledge during the Dark Ages (5th–11th centuries) in the libraries of the monasteries. Religion has also held medicine back. The ban on dissection imposed by religious beliefs forced anatomists such as Galen, an influential Greek physician of the 2nd century AD, to dissect pigs, monkeys, and other animals and then draw incorrect conclusions about the human body. During the Middle Ages, both Islamic and Roman Catholic faiths continued this ban. In Europe medicine was further retarded until the Renaissance because the Christian church insisted that Galen's theories about the human body, such as a threefold circulation, were infallible (perfect) and taught them to medical students in universities controlled by the church.

War The role of war in medicine has influenced the rate of change on many occasions. War sometimes helps to advance medical knowledge, such as the French military surgeon Ambroise Paré's discovery of a new treatment for gunshot wounds in the 16th century. Harold Gillies in World War I and Archibald McIndoe in World War II pioneered the development of modern plastic surgery. The casualties of war gave these doctors opportunities and challenges that they may not have had to face. War can, however, slow medical progress. Attacks on the Roman Empire by the barbarian tribes of northern Europe contributed to its collapse and the destruction of the medical knowledge amassed in Rome. During the subsequent era of the Dark Ages, medicine regressed in Europe. Medical treatment in World War I was often less developed or successful than it had been before the war as there were too many casualties to take time over their treatment.

Chance The role of luck or chance findings has often advanced medicine with key discoveries. Paré's new treatment for gunshot wounds, the application of soothing balms and use of ligatures to tie off blood vessels, was adopted in part because the oil used in the traditional treatment of cauterizing ran out. Alexander Fleming's discovery of penicillin in 1928 was a chance event that later allowed the full development of the drug by Florey and Chain.

Communications The ability to communicate medical knowledge to other doctors and to obtain new ingredients has helped medicine to develop. The ancient Egyptians and Greeks were able to produce complicated medical treatments from plants and spices obtained by communicating and trading with other nations. The books of Galen were preserved in Arabic by Middle Eastern scholars after the fall of the Roman Empire in AD 476, and later translated back into Latin. Galen's On Anatomical Procedures was lost to Europe in this way for over a thousand years until Johannes Guinter translated it from the Arabic in 1531. Voyages of discovery undertaken by European explorers from the 15th century opened up the medical knowledge and ingredients of the Americas and Asia to European medicine. The introduction of the printing press into Europe in the 1450s by the German printer Johannes Gutenberg enabled medical knowledge to spread more quickly. Fleming recorded his discovery of penicillin in a medical journal, and the articles were later read by Florey and Chain who went on to develop the drug. Doctors attend conferences where they can share knowledge and discoveries.

Individuals It is often the genius or hard work of specific individuals that leads to medical change. Rational medicine was advanced through the work of Hippocrates in ancient Greece, and anatomical knowledge was based on the works of Galen for over 1,000 years. During the Renaissance the determination and skills of the Flemish anatomist Andreas Vesalius were crucial to the decline of Galen's monopoly over medical thinking. The work of English social reformer Edwin Chadwick, who highlighted public health problems in 19th-century Britain, greatly advanced the cause of reform. The determination of Elizabeth Garrett Anderson and Sophia Jex-Blake to be accepted as doctors in what had traditionally been a male profession changed medicine by introducing women into the profession. Fleming's skills led him from the observation of an unusual mould growing in a petri dish to the discovery of penicillin, where another doctor may not have realized its importance. Individual skills and genius have been crucial in driving forward medical knowledge.

Science and technology The development of technology has enabled the expansion of medical knowledge. The Romans were able to build a public health system with aqueducts and baths because of the advances in building construction made in the Roman era. The invention of the microscope in 1609 allowed scientists to see things that had previously been invisible to the naked eye, such as the germs discovered by Louis Pasteur around 1860. New operations have been developed such as heart transplants because of the invention of the heart–lung machine technology available to surgeons. Keyhole surgery using fibre-optic endoscopes has enabled surgeons to advance medicine. Technology gives doctors the tools to develop medicine.

Conservatism Conservatism in medicine is opposition to change. In general conservatism has slowed medical development. Many physicians opposed Paré's ideas as they were new and challenged the accepted practices of previous centuries. Although Edward Jenner's use of cowpox as inoculation against smallpox proved successful, most doctors ignored his findings and had little respect for Jenner as a professional. Many doctors were slow to take up the discovery of antiseptic by Joseph Lister in the 1860s as they refused to change their methods. The potential benefits of new discoveries can take time to filter through because of conservatism. However, conservatism in medicine can have benefits. Doctors who require absolute proof of the effectiveness of a new discovery may avoid using unproven and potentially dangerous methods until their safety is confirmed.