Claude Bernard was a 19th century proponent of medicine based on evidence.

The French physiologist Claude Bernard (1813-1878) has the unfair reputation of being ferociously opposed to the use of probabilities and statistics in medicine. In the 19th century, he would have been included among those who opposed the emergence of what would eventually become clinical epidemiology. The truth is that Bernard valued the role of medical statistics in clinical medicine but viewed it as potentially misleading in laboratory-based physiology. He posited that clinical medicine had to be guided by probabilistic evidence as long as physiological mechanisms remained unknown. Bernard praised the clinical researches of Pierre Louis aiming to assess the efficacy of bloodletting in the treatment of pneumonitis. The real objects of Bernard's contempt were the physicians who pretended that medicine was an art strictly based on intuition and tact and who pretended that comparative trials and statistics were useless for clinical medicine. Overall, Bernard was a strong and explicit proponent of the importance of scientific evidence in medical knowledge, be it from experiments or from comparative trials.