How the Church affected the development of science in the Dark and Middle Ages

This post by James McDonald originally appeared at Bad News About Christianity.

The Dance of Death by Michael Wolgemut. (Credit: Wikipedia / Public Domain)

The ascendancy of the Christian Church dates from around the time of the death of Galen. Having progressed so far, rational medicine was now abandoned. Medicine in the Bible is entirely supernatural. The Church developed the view that real practical medicine savoured of black magic. In any case it was wrong to try to subvert God’s holy will by interfering with the natural course of events. It was God who caused illness. He was responsible for cures just as he was responsible for death. Even church law mentioned, in passing, that diseases were attributable to God, for example

If, by divine judgment, leprosy happens to a husband or wife, and the sick one demands the carnal debt from the one who is healthy, what is demanded must be rendered in accord with the Apostle’s general commandment [1 Cor. 7:3-4], which gives no exception for this case.
(Decretals of Pope Gregory IX , Book Four, Title VIII C2)

Illness was indisputably caused by sin. The Bible said so, and so did Church Councils. The only alternative explanations given credence were diabolical possession, witchcraft and other satanic machinations. In Christendom, from AD 300 to around 1700 all serious mental conditions were understood as symptoms of demonic possession. Since illness was thought to be caused by supernatural agents, cures had to be essentially supernatural as well. Every cure was literally miraculous, and these miracles could be effected only by prayer, penance and the assistance of saints. To claim otherwise was heretical and blasphemous.

The Christian ideal was that women should die rather than allow themselves to be helped by a physician. Some women won their sainthood for doing no more than declining medical assistance. In the fourth century Saint Gorgonia, the daughter of two saints, was trampled by a team of mules, causing multiple broken bones and crushed internal organs. She would not see a doctor, as she thought it indecent. According to Christian sources this modesty miraculously cured her, and a second such self-healing miracle assured her sainthood. Today, Gorgonia is a patron saint for people afflicted by bodily ills. We do not know how many thousands of other women with identically modest Christian scruples died following her example and are now forgotten.

All manner of illnesses were allocated a patron saint, whose intervention was required to work the required miraculous cure. Ergotism, known as sacer ignis or holy fire, was held to be alleviated by the intervention of the Virgin Mary. Erysipelas, an infectious disease causing a reddening of the skin, was dealt with by St Anthony the Great and was thus called St Anthony’s fire. St Vitus took care of chorea, which was thus known as St Vitus” dance. St Basilissa took care of chilblains; St Elmo of colic; St Roche of cholera; St Lucy, eye diseases; St Blaise, throat problems; St Apollonia, toothache; St Fiacre, haemorrhoids and venereal disease; and so on. Sleepwalking and insanity were regarded as manifestations of diabolic possession and both came under the care of St Dympna, the patron saint of the possessed. There was literally a saint for every disease.

Other holy people could work miracles too; for example scrofula (a form of tuberculosis) could be cured by the touch of kings, by virtue of their divine appointment. It was thus known as The King’s Evil. French and English kings worked miraculous cures for centuries. Even Protestants accepted it. From 1634 until the mid-eighteenth century, the Book of Common Prayer included a ritual of royal healing, and the rituals continued later still. Dr Samuel Johnson, as a child, was touched by Queen Anne as late as 1712, and there were still people attributing the power to Queen Victoria in the nineteenth century.

By the Middle Ages, medicine had regressed on all fronts in Christian lands. Muslims who came into contact with Christians, as Usama of Shaizar did during the Crusades, were shocked by the crudity of their medicine — and it was not only medicine, but public health too. Whereas Muslims adopted public baths (hammams) and insisted on washing before meals, Christians adopted the view that it was wrong to wash. It was flying in the face of God to presume to clean off his honest Christian filth. Christians were obliged to accept the will of God and the disease and misery that went with it. Queen Elizabeth I was famously said to have bathed twice a year, whether she needed to or not.

The practice of medicine was monopolised by the Church, so laymen who practised it became criminals. Then the Church stopped certain clergymen practising it as well. Monastic medicine was prohibited by the Synod of Clermont in 1130. Thenceforth the practice of medicine was reserved to the secular clergy. A generation later, in 1163, the Council of Tours prohibitted all scientific inquiry to monastics, and this was interpreted as including surgery, although the Council did not explicitly use the maxim often cited, ecclesia abhorret a sanguine (the church abhors blood). All studies of physical nature, including medicine, were confirmed as inherently sinful as anyone who pursued such studies must be in league with the Devil.

To the extent that it survived at all surgery was now the province of barbers, executioners, bath-keepers and proto-veterinarians. Monks now went off to the barber-surgeon for the dual purpose of having their tonsures shaved and their arms bled, but this was about the limit of surgical health care permitted by the Church. The much cited maxim ecclesia abhorret a sanguine seems to have been interpreted as “The Church abhors bloodshed” because fresh prohibitions were included in the 18th cannon of the Fourth Lateran Council in 1215:

18. Clerics to dissociate from shedding-blood
No cleric may decree or pronounce a sentence involving the shedding of blood, or carry out a punishment involving the same, or be present when such punishment is carried out. If anyone, however, under cover of this statute, dares to inflict injury on churches or ecclesiastical persons, let him be restrained by ecclesiastical censure. A cleric may not write or dictate letters which require punishments involving the shedding of blood, in the courts of princes this responsibility should be entrusted to laymen and not to clerics. Moreover no cleric may be put in command of mercenaries or crossbowmen or suchlike men of blood; nor may a subdeacon, deacon or priest practise the art of surgery, which involves cauterizing and making incisions; nor may anyone confer a rite of blessing or consecration on a purgation by ordeal of boiling or cold water or of the red-hot iron, saving nevertheless the previously promulgated prohibitions regarding single combats and duels.

Dissections of dead bodies were permitted in selected universities, but nothing of any value was learned because no research was carried out. The wisdom of the ancients was repeated to students parrot fashion — including their errors, such as the liver’s five lobes (which do not exist in human beings). By now Galen, even though a pagan, was recognised as knowing more than any Christian, so his word like Aristotle’s, was treated as indisputable. For hundreds of years, everyone saw what he or she was supposed to see, rather than what was actually there:

During these dissections the learned professor would read aloud from Galen while a lowly surgeon opened the body. Then the professor would point toward the organ and describe the five-lobed liver and other miracles of Galenic anatomy, such was the blinding weight of tradition and authority.

Freelance anatomy for original research was illegal. Scientists like Leonardo da Vinci were obliged to carry on their anatomical research in secret. Leonardo’s famous mirror writing was used to disguise his findings, in case the Church authorities found out about them. His notes were not published for more than 200 years after his death.

Michelangelo was another secret anatomist. He apparently managed to work some of his anatomical discoveries into his art, including The Creation of Adam, a section of his fresco in the Sistine Chapel ceiling (c 1511).

Many Christian ideas about biology were spectacularly wrong. Leading theologians taught that women had more water in their bodies than men, so if a humid south wind blew during pregnancy, or if there were frequent rains, the baby was more likely to be born female. The functions of the organs were also misunderstood. According to the approved view the liver secreted yellow bile; the spleen, black bile; the heart, blood; and the brain, phlegm. A Greek thinker, Alcmaeon of Crotona, had identified the brain as the central organ in the higher activities of humankind around 500 BC, but 2,000 years later Christian authorities were teaching that the brain was merely a phlegm-secreting gland.

More detail, with dozens of images and references at

Reprinted with permission from the author.

James McDonald is Fellow of the Royal Geographic Society in Britain, and holds a number of professional qualifications. He also holds an MA in mathematics from Oxford University, and an MSc in Operational Research from Sussex University. He lives in the South of France. His newest book is Beyond Belief: Two Thousand Years of Bad Faith in the Christian Church (Garnet Publishing, 2009). His website is

How the Medieval Church Frightened People Into Obedience

How Powerful was The Pope in Medieval Times?

The Dark History Of The Catholic Inquisition | Secret Files Of The Inquisition | Parable

Be sure to ‘like’ us on Facebook



Please enter your comment!
Please enter your name here