From the 5th through the 11th century, knowledge of science and literature was limited to a select few, such as the clergy, according to historian Edward Withington in his 1894 book "Medical History from the Earliest Times," (1, page 175).
In the meantime, during the dark ages, if you didn't have a need to know, you were left in the dark, literally. This is one reason the Middle Ages, the Medieval era, is so often referred to as the Dark Ages. People were kept illiterate and ignorant, and for the most part they accepted this ignorance as the path to eternal life in heaven.
For the most part, and with only a few exceptions, the Ancient Greek language was all but unknown in Western Europe. This was unfortunate because "at this time Greek was still the key to all higher knowledge, especially in medicine," said Withington. "Latin versions of some Galenic treaties, indeed, existed, yet they were so little known that Constantine the African (1020-1087) could boast in the eleventh century that he was the first to translate that author. Celsus, whose work might have formed an excellent text-book, was almost entirely forgotten." (1, page 176)
William Osler, in a 1913 lecture at Yale, explained that "Knowledge other than that which made a man 'wise unto salvation' was useless. All that was necessary was contained in the Bible or taught by the Church. This simple creed brought consolation thousands and illumined the lives of some of the noblest of men. But 'in seeking a heavenly home man lost his bearing upon earth.'" (2, page 85)
With a few exceptions, most people didn't need natural remedies to treat diseases, and they didn't seek to know the diagnosis nor the prognosis of disease. They lived the hard life, and they prayed to God for health and for healing. They did not need natural medicine. They did not need physicians. All they needed, as Osler noted, was the Bible and the Church.
While the dark ages for western civilization ended in the 11th century, the dark ages of medicine lingered on until the 16th century. Thankfully, however, while the west was clouded by the dark ages, the opposite was occurring in the east, where there was a bright cloud, and medicine flourished.
- Withington, Edward Theodore, "Medical History from the Earliest Times: A Popular History of the Art of Healing," 1894, London, The Scientific Press.
- Osler, William Henry, "The Evolution of Modern Medicine: A series of lectures delivered at Yale..." page 85