Circulation: William Harvey's Revolutionary Idea, By Thomas Wright

How anyone recovered from serious illness in the 1600s is beyond me. According to Thomas Wright, diagnosis consisted of urine-sniffing and treatments included leeching, belly rubs and (most useless of all) abstinence from alcohol. William Harvey (1578-1657), the subject of Wright's book, was responsible for helping to bring about a world in which these so-called cures would be exposed as quackery.

The discovery of the circulation of blood by the heart is an insight so fundamental to medical knowledge that it is salutary to be reminded that it was not merely greeted with incredulity by many who were highly erudite, but its author was regarded almost as a heretic. In the early 17th century, the principles of the Roman philosopher Galen still reigned supreme. Doctors believed our well-being to be governed by four humours (blood, black bile, yellow bile and phlegm), each supposed to reside in a different part of the body. Imbalances among them caused illness. Doctors thought blood was generated in the liver, which distributed it to the other organs. Such ideas may sound ridiculous, but when Harvey joined the Royal College of Physicians, it was a condition of membership that one took an oath never to contradict them.

It is one of the more bracing lessons of this book that history is ruthless: the name of William Harvey, not that of James Primrose, nor of other dissenters from Harvey's theories, is remembered now. And with good reason: he was right. Harvey's comparison of the heart to a pump was, as Wright observes, "the analogy to end all analogies". That mechanistic concept refocused thought so that Descartes could formulate his theory of a clockwork universe, while Thomas Hobbes (a friend of Harvey) could propose that monarchy was an artificial device rather than ordained by God.

All of which makes it ironic that bloodletting (a form of treatment authorised by Galen) remained standard practice until well into the 19th century, 200 years after Harvey had demonstrated its utter uselessness. As late as 1824, Lord Byron was killed not by the swamp fever he contracted at Missolonghi but by the vigorous leeching recommended by doctors.

In Circulation, Wright tells a good story, warts and all. By Wright's own admission, Harvey was "bookish and conformist by temperament", had "proficiency in cat and dog cutting" (alarmingly for animal lovers), and was motivated by the desire for fame – none of which makes him loveable.

Wright's solution is to glance at the personality while concentrating on the ideas. Though cast as a biography, this is really the story of an idea – a simple one, though it was to change human thought forever. Wright reconstructs the research Harvey must have performed – autopsies on numerous human beings, vivisections on animals – and shows how it led to a new theory of human physiology. He pulls no punches in his descriptions of medical procedures.

Wright is attentive to the world in which his subject lived, and recreates a finely-graded sense of the defensiveness that surrounded Galenic medicine, propped up by those whose lucrative careers were licensed by it. The semi-medieval conditions of life at the universities of Cambridge and Padua are well-described, particularly Padua's circular anatomical theatre (which still exists), in which members of the public were crammed into a tight space for hours alongside medical students and professors. "The press of so many people packed tightly into such a small, illuminated, windowless space, and the height of the middle and upper galleries, induced in some spectators nausea and vertigo." Students were worse behaved than now: they fought duels during dissections, while the Italians engaged in "loud slanging matches" with the Germans. Amid all this, lute-players would accompany the demonstrations in an effort to calm everyone down.

Towards the end of the book, Wright describes how Charles I commended his two sons to Harvey's care just before the Battle of Edgehill, and quotes Harvey's recollection that he "withdrew with them under a hedge, and took out of his pocket a book and read; but he had not very long before a bullet of a great gun grazed on the ground near him". This vignette lends an added dimension to this remarkable man, born 14 years after Shakespeare, who lived long enough to witness the execution of God's vice-regent upon earth.

Circulation portrays a complex personality –part-time property speculator, silly enough to impersonate ducks and puffins in the operating theatre, and sufficiently unsentimental to autopsy his own father's corpse.

Duncan Wu is professor of English at Georgetown University