William Harvey Describes the Circulation of Blood

English physician William Harvey (1578–1657) published Exercitatio Anatomica de Motu Cordis et Sanguinis in Animalibus in 1628, demonstrating through quantitative experiment and dissection that blood circulates continuously through the body, driven by the heart acting as a pump. This overturned Galen's 1,400-year-old model in which blood was produced in the liver and consumed by the body. Harvey's use of measurement and controlled observation to challenge inherited doctrine became a model for the emerging scientific method in medicine.