William Cowper, now virtually forgotten, was the first of the surgeon-scientists of Great Britain. He was the first to bring the power of the experimental method to bear on practical surgical problems and to urge that the principles of surgery be drawn from an understanding of the "animal oeconomy." In these areas he anticipated the celebrated Hunterian school of surgery by more than half a century and by his example he actually set the foundation on which that school was built. Cowper was a scientist of a high order. He was the first to prove the existence of capillaries in higher mammals, to describe naturally occurring arteriovenous shunts in the lungs and spleen, to define the essential physiology of aortic valvular disease, and to recognize the nature and consequences of arteriosclerotic vascular disease. He was the author of two important anatomy books and the first English language treatise on general physiology available to surgeons. He was one of the first two surgeons ever honored by election to the prestigious Royal Society of London. An analysis of the works and doctrines of William Cowper appears to cast serious doubt on the common teaching that the idea of "scientific surgery" was the sole creation of John Hunter.