Who criticized William Harvey’s circulation theory?

William Harvey’s theory of blood circulation faced opposition from conservative physicians who continued to adhere to the traditional teachings of Galen, which posited that blood moved in an ebb-and-flow motion within the vessels. Many of these critics rejected Harvey’s findings without attempting to replicate his experiments, preferring to rely on established authority rather than the new experimental method.1

Specifically, the French anatomist Jean Riolan was a notable critic of the theory, prompting Harvey to publish Exercitationes Duae Anatomicae de Circulatione Sanguinis, ad Joannem Riolanem, Filium, Parisiensem in 1649 to address his objections. Despite this initial resistance, Harvey’s work was well established by the time of his death.2