Isaac Newton: Rules for reasoning scientifically
William Harvey, Bacon's physician, wrote of his discovery of the circulation of the blood in his De motu cordis (On the motion of the heart) , published in 1628. Not long afterwards, René Descartes read the book and in his own first publication - the Discourse on the Method of 1637 - gave prominence to Harvey's discovery. Though there were some who rejected Harvey's claim, including a number of anatomists, Descartes made it quite plain that his own anatomical work had led him to the conclusion that the blood does circulate around the body. Where the two men disagreed was about why the blood circulates. The debate has a factual scientific side but, as both Harvey and Descartes realised, it also raised questions about scientific method. These questions show that, although Harvey's emphasis upon the role of what he called 'ocular experiments', or anatomical dissections and vivisections, make him seem Baconian in his method, the same emphasis suggests a close connection with aspects of Galileo's ideas about method. And they show, too, that, although Descartes assigned a role to reason in science which made him seem Galilean in his method, his criticisms of Harvey echo some features of the Baconian method in experimental science.