Claude Bernard was a French physiologist born on July 12, 1813, and is often regarded as one of the founders of modern experimental medicine. He is best known for his work on the concept of the milieu intérieur, which refers to the stable internal environment of an organism. His research laid the groundwork for understanding how the body maintains homeostasis. Bernard's contributions to science include the discovery of the role of the pancreas in digestion and the importance of the liver in metabolism. He emphasized the significance of controlled experiments in scientific research, influencing future generations of scientists and medical professionals.