William Harvey

In 1628 Harvey published at Frankfurt the Exercitatio Anatomica de Motu Cordis et Sanguinis in Animalibus, a short quarto of 72 pages. Arguing from the structure of the heart and its valves, from experiments on living animals including ligatures on a snake, and from the amount of blood the heart sends out, he concluded that the blood travels in a continuous circuit, pumped from the right ventricle through the lungs and from the left ventricle round the body, and returns to the heart by the veins. He had first stated this in his lectures of April 1616.

Harvey was elected Lumleian lecturer in anatomy and surgery at the College of Physicians of London on 4 August 1615 and held the post until he resigned in 1656. His surviving notes for the lectures of 16-18 April 1616, the first public statement of the circulation, show that he had by then dissected more than eighty species of animals and used animal anatomy to explain the human body.

In 1651 Harvey's Exercitationes de Generatione Animalium appeared in London, after George Ent had taken the manuscript from him at Christmas 1650. The book describes the parts of the hen's egg and follows the growth of the chick inspection by inspection. Norman Moore judged that it shows great labour and careful observation, though the microscope was still needed to make much of it clear.

In May 1636, travelling with the Earl of Arundel's embassy to the emperor, Harvey reached Nuremberg and offered to demonstrate the circulation to Caspar Hofmann, a professor who opposed it. He gave a demonstration there, which Keynes places at the University of Altdorf, but Hofmann remained unconvinced and the two exchanged letters afterwards. A later tradition adds that Harvey laid down his knife and left when the objections continued.

Offering a demonstration on the spot, rather than an argument by letter, fits persuasiveness, though the unconvinced Hofmann shows that it did not work on a determined opponent; the walk-out is tradition and is not relied on. Persuasiveness

John Aubrey, who first saw Harvey at Oxford in 1642, recalled that Harvey came several times to Trinity College to see George Bathurst, who kept a hen hatching eggs in his rooms. They opened one egg every day to follow the progress and way of generation.

Setting up a simple daily test and repeating it over several days is consistent with experimentation; the account rests on Aubrey's memory alone. Experimentation

After lecturing on the circulation at the College of Physicians every year since 1616, Harvey sent De Motu Cordis to press at Frankfurt in 1628, saying in the proem that some fellows reproached him for departing from all anatomists and that friends had urged him to publish. Opposition followed: James Primrose's reply appeared in 1630 and Parisanus's in 1635, and Aubrey reports Harvey saying that his practice fell off and that physicians were against him, though D'Arcy Power suggests the court's politics also played a part. Norman Moore concludes that before Harvey's death the doctrine was accepted throughout the medical world.

Publishing a doctrine he expected to draw hostility, then largely declining to answer the critics, is a mixed picture for conflict tolerance: he accepted open disagreement over the idea but avoided polemical exchange. Conflict Tolerance