Claude Bernard

Claude Bernard (1813-1878), French physiologist, regarded as the founder of experimental medicine. Born in St-Julien, Bernard received a humanistic education during his youth; he did not take any classes exploring the physical or natural sciences. After leaving school at 18, he wrote two plays, but the eminent French critic Saint-Marc Girardin, upon reading the second one, suggested to Bernard that he find a different career. In 1834 Bernard enrolled in the Paris School of Medicine, and after a few years he obtained a position at a laboratory at the Collège de France, where he worked under the French physiologist François Magendie.

Bernard received his medical degree in 1843 and went on to make a series of important discoveries in physiology. In 1846, by means of experiments on rabbits and other animals, Bernard discovered the role of the pancreas in digestion. He showed that the pancreas secretes a fluid that allows fat to be digested. Later, he discovered the role of the liver in the transformation, storage, and use of sugar in the body. He also explored functions of the autonomic nervous system— in particular, he discovered the function of the vasomotor nerves, which are responsible for regulating blood supply by constricting or dilating blood vessels.

In addition to his work in experimental physiology, Bernard made contributions to other fields in the natural and experimental sciences. Most notably, his insistence that an experiment should be designed to either prove or disprove a guiding hypothesis is an integral part of the modern scientific method. Also, in trying to understand how the systems of an organism maintain a state of balance, he was the first to propose the concept that later became known as homeostasis.

Because of his many important discoveries, Bernard became a prominent scientist during his lifetime. In 1854 he accepted the newly created chair of physiology at the Sorbonne. When Magendie died in 1855, Bernard took over his post at the Collège de France; he held the positions at the Sorbonne and the Collège de France concurrently until 1868. In 1855 Bernard also became a member of the French Academy of Sciences. Upon his death in 1878, Bernard received a public funeral—the first time a scientist had received such an honour in France.