Claude Bernard (1813-1878) is an influential physiologist and best known for pioneering blind experiments. Wikipedia says,
Claude Bernard's aim, as he stated in his own words, was to establish the use of the scientific method in medicine. He dismissed many previous misconceptions, took nothing for granted, and relied on experimentation.
This post is a collection of quotes from Bernard regarding the philosophy of science.
Support for experiments
"Theories are only verified hypotheses, verified by more or less numerous facts. Those verified by the most facts are the best, but even then they are never final, never to be absolutely believed." (Introduction à l'Étude de la Médecine Expérimentale, 1865)
"A man of science rises ever, in seeking truth; and if he never finds it in its wholeness, he discovers nevertheless very significant fragments; and these fragments of universal truth are precisely what constitutes science." (Introduction à l'Étude de la Médecine Expérimentale, 1865)
"We must never make experiments to confirm our ideas, but simply to control them." (Bulletin of New York Academy of Medicine, 1928)
Critique of statistics
"A great surgeon performs operations for stone by a single method; later he makes a statistical summary of deaths and recoveries, and he concludes from these statistics that the mortality law for this operation is two out of five. Well, I say that this ratio means literally nothing scientifically and gives us no certainty in performing the next operation; for we do not know whether the next case will be among the recoveries or the deaths. What really should be done, instead of gathering facts empirically, is to study them more accurately, each in its special determinism… to discover in them the cause of mortal accidents so as to master the cause and avoid the accidents." (Introduction à l'Étude de la Médecine Expérimentale, 1865)
"Indeed, proof that a given condition always precedes or accompanies a phenomenon does not warrant concluding with certainty that a given condition is the immediate cause of that phenomenon. It must still be established that when this condition is removed, the phenomen will no longer appear." (Introduction à l'Étude de la Médecine Expérimentale, 1865)