William Harvey (1578-1657), an English physician who first described in detail the circulatory system of blood pumped around the body by the heart. Conventional wisdom of the time held that food was converted into blood by the liver, and was then consumed as fuel by the body. In 1628, Harvey published An Anatomical Study of the Motion of the Heart and of the Blood in Animals that explained how blood was pumped from the heart throughout the body, and then returned to the heart to recirculate. Many viewed Harvey’s work as a development of the ideas of René Descartes, who viewed arteries and veins as pipes that carried nourishment around the body, and of Ibn Nafis, who had described some of the principles of major arteries and veins in the 13th century. Harvey's ideas were not accepted during his lifetime and thus had little effect on general medical practice at the time. Bloodletting, a practice based on the false theories of Galen, continued to be a popular practice during this time.
Cutler J. Cleveland (Lead Author);Peter Saundry (Topic Editor) "Harvey, William". In: Encyclopedia of Earth. Eds. Cutler J. Cleveland (Washington, D.C.: Environmental Information Coalition, National Council for Science and the Environment). [First published in the Encyclopedia of Earth January 17, 2009; Last revised Date January 17, 2009; Retrieved June 19, 2013 <http://www.eoearth.org/article/Harvey,_William>