Homer is the fountainhead of so much in Greek culture, and that includes literary doctors. In the Iliad, Machaon and Podalirius, the sons of the god Asclepius, are Greek warriors famed for their prowess in healing and field surgery. They appear on the coat of arms of the Royal College of Surgery to this day. In the Odyssey, Helen gives her husband, Menelaus, and other war veterans a drug that makes them forget the horrors of the conflict; early treatment for post-traumatic stress, perhaps?

In about 500BC, the cult of Asclepius sprang up in Greece. If you slept in his sanctuary, your dreams might help you find a cure. In the second half of the 5th century BC, a doctor called Hippocrates became celebrated for his skill, and was one of the authors of a number of texts known collectively as the Hippocratic Corpus.

Some of this material reads oddly, to say the least, today. Among the pronouncements are that people who lisp are prone to diarrhoea; that sperm originates in the head and travels down through the marrow before reaching its usual outlet; and that the excessive horseriding of the Scythians makes them impotent. In the Hippocratic text called Airs, Waters, Places, we read that environment has a crucial effect on health. Those exposed to the south wind can expect moist heads full of phlegm, haemorrhoids and, for women, vaginal discharges.

All that said, most of the Hippocratic Corpus favours diagnosis based on observation and is based on the idea that disease is a naturally explicable phenomenon, rather than caused by divine wrath or other supernatural factors. And the Hippocratic oath can be seen as the first statement of medical ethics - doctors are to swear to help and not harm patients, and to honour patient confidentiality.

Charlotte Higgins is the author of It's All Greek To Me (Short Books)