How did Claude Bernard challenge the idea of a vital force as an explanation for life?

Claude Bernard challenged the concept of a vital force by shifting the study of life toward rigorous experimental medicine. Rather than relying on the vague, non-predictive notions of vitalism—which posited that living organisms were animated by an inherent, mysterious life force—Bernard championed the use of systematic experimentation to understand biological processes.12

He advanced beyond the indeterminism of earlier physiologists by demonstrating that vital processes could be explained through physical and chemical mechanisms. His most significant contribution in this regard was the concept of the internal environment, or milieu intérieur. By showing that organisms maintain stability through self-regulation—a process now known as homeostasis—Bernard provided a scientific, observable framework for life that did not require the invocation of supernatural or vitalistic entities. His work helped establish the principle that biological phenomena are subject to the same laws of nature as inert matter, thereby grounding biology in empirical science.1