On the Motion of the Heart and Blood in Animals (De Motu Cordis), published in 1628 by English physician William Harvey, is a landmark treatise that forever changed medical science. Through meticulous dissection, observation, and mathematical reasoning, Harvey demonstrated that the heart functions as a pump, driving blood through the body in a continuous circular motion. His findings boldly overturned Galen's centuries-old belief that blood was endlessly produced and consumed. Though initially met with fierce controversy, Harvey's rigorous experimental method established the foundation of modern physiology. This slim volume remains one of the most influential works in the history of medicine.
