When publishing his first book anonymously at Leyden in 1637, Descartes showed his deep interest in medicine. Part five of the Discourse on Method offers a detailed account of the movement of the heart and discusses Harvey’s discovery of the circulation of blood. We should note that in the margins of the Discourse on Method, William Harvey’s name is mentioned in Latin and so too is the title De motu cordis. Furthermore, in the text, Descartes speaks of “an English physician, (...) who must be praised for having broken the ice” on the circulation of the blood. Harvey is indeed the only author who is mentioned by name in the Discourse, and his name is mentioned with the respect due to a genuine discoverer. These pages in the fifth part of the Discourse offer a totally new way of dealing with medical questions in the first part of the seventeenth century. I will consider here the Descartes-Harvey debate on the cause of the movement of the heart and Descartes’ approbation of Harvey’s discovery of the circulation of the blood. Yet, the medical context of the seventeenth century must be taken into account if we are properly to understand Descartes’ attitude towards Harvey, as well as the medical goals that Descartes had in mind when he attempted to explain the movement of the heart. (shrink)