What arguments did Claude Bernard make about vital force in experimental medicine?

In his seminal work, An Introduction to the Study of Experimental Medicine, the French physiologist Claude Bernard argued against the prevailing reliance on the concept of a "vital force" to explain biological phenomena.1

Bernard contended that the notion of a vital force does not provide a scientific explanation for life. Instead, he asserted that biology must be founded on the principle that life processes are mechanistically determined by physico-chemical forces. While he maintained that the physical and chemical sciences provide the necessary foundation for physiology, he also noted that physiology is not entirely reducible to those sciences alone.1

By moving beyond the vitalism and indeterminism of his predecessors, Bernard helped establish the rigorous principles of experimentation that define modern medicine. His work emphasized that medicine must be grounded in experimental physiology to progress, a shift that remains fundamental to our current understanding of homeostasis and the body's internal environment.21