Claude Bernard was born in the village of Saint-Julien near Villefranche-sur-Saône.

Bernard was important as a developer and teacher of experimental methods in medicine. He was a professor of physiology in Paris and developed rules for experimentation in medicine. Bernard believed that ‘[s]cientific medicine, like the other sciences, can be established only by experimental means, i.e. by direct and vigorous application of reasoning to the facts furnished us by observation and experiments’. He published his recommendations for the experimental method in a very influential work, An Introduction to the Study of Experimental Medicine (1865).

His experiments shed light on the process of digestion, and the function of organs such as the liver and nerves. Much of Bernard's work was based on experiments with living animals. Many people opposed this method, including Bernard's own family, and he eventually fell out with his wife and daughters because they contributed to the anti-vivisection movement.