Vivisection

The practice of true vivisection dates back to ancient times. Around 500 B.C., one of the earliest known vivisectionists, Akmaeon of Croton, discovered that the optic nerve is necessary for vision by cutting it in living animals. One of the most well known—and controversial—early vivisectionists was Galen of Pergamon, physician to Roman Emperor Marcus Aurelius. Galen, who lived in the second century A.D., is remembered today for his pioneering use of vivisection of animals to understand health and disease in the human body. But Galen was also a poor scientist, failing to identify such major bodily functions as the circulation of the blood. An unquestioning adherence to Galen's false beliefs in succeeding generations of physicians was undoubtedly a major hindrance to medical progress in Europe.

Real progress in medical knowledge began again with the experiments of the Italian physicians Andreas Vesalius and his student, Realdo Colombo, in the sixteenth century. They pioneered the use of vivisection to correct and expand, rather than merely to confirm, Galen's science. In the early seventeenth century, English physician William Harvey used vivisection to discover the circulation of the blood and to debunk many of Galen's other beliefs.

But this century also saw the beginnings of an anti-vivisectionist movement. Physician Jean Riolan Jr. in France and Irish physician Edmund O'Meara both argued that the painful and violent deaths suffered by vivisected animals—remember, there was no anesthesia yet—were putting the animals into an unnatural state that could lead to faulty assumptions about the functioning of a healthy animal.

Also in this century, vivisection received an important philosophical boost from the French philosopher René Descartes. Descartes believed that the mind and the body are separate entities, and that animals differ from humans in that they have bodies but no true minds. As such, animals were morally no different from machines, and so vivisection was not morally wrong. Descartes even went so far as to say that animals did not feel real pain (a belief that is sometimes still repeated today, although few believe it to be true), although he stressed that vivisection was primarily defensible because it helped humans, not because hurting animals was right. Unfortunately, some of Descartes's later followers lost this fine distinction, and were known for their gratuitous cruelty to animals.