"It is what we know already that often prevents us from learning."
— Claude Bernard (1813-1878)
"The experimenter who does not know what he is looking for will not understand what he finds."
— Claude Bernard (1813-1878)
"When we meet a fact which contradicts a prevailing theory, we must accept the fact and abandon the theory, even when the theory is supported by great names and generally accepted."
— Claude Bernard (1813-1878)
"Man can learn nothing unless he proceeds from the known to the unknown."
— Claude Bernard (1813-1878)
"All the vital mechanisms, varied as they are, have only one object, that of preserving constant the conditions of life in the internal environment."
— Claude Bernard (1813-1878)
"We must keep our freedom of mind, ... and must believe that in nature what is absurd, according to our theories, is not always impossible."
— Claude Bernard (1813-1878)
"Those who do not know the torment of the unknown cannot have the joy of discovery."
— Claude Bernard (1813-1878)
"The terrain is everything; the germ is nothing."
— Claude Bernard (1813-1878)
"Men who have excessive faith in their theories or ideas are not only ill prepared for making discoveries; they also make very poor observations. Of necessity, they observe with a preconceived idea, and when they devise an experiment, they can see, in its results,only a confirmation of their theory. In this way they distort observation and often neglect very important facts because they do not further their aim."
— Claude Bernard (1813-1878)
"A discovery is generally an unforeseen relation not included in theory."
— Claude Bernard (1813-1878)
"Art is 'I'; science is 'we'."
— Claude Bernard (1813-1878)
"A fact in itself is nothing. It is valuable only for the idea attached to it, or for the proof which it furnishes."
— Claude Bernard (1813-1878)
"We must never make experiments to confirm our ideas, but simply to control them."
— Claude Bernard (1813-1878)
"In science, the best precept is to alter and exchange our ideas as fast as science moves ahead."
— Claude Bernard (1813-1878)
"The eloquence of a scientist is clarity; scientific truth is always more luminous when its beauty is unadorned than when it is tricked out in the embellishments with which our imagination would seek to clothe it."
— Claude Bernard (1813-1878)
"We must alter theory to adapt it to nature, but not nature to adapt it to theory."
— Claude Bernard (1813-1878)
"I do not ... reject the use of statistics in medicine, but I condemn not trying to get beyond them and believing in statistics as the foundation of medical science. ... Statistics ... apply only to cases in which the cause of the facts observed is still [uncertain or] indeterminate. ... There will always be some indeterminism ... in all the sciences, and more in medicine than in any other. But man's intellectual conquest consists in lessening and driving back indeterminism in proportion as he gains ground for determinism by the help of the experimental method."
— Claude Bernard (1813-1878)
"First causes are outside the realm of science."
— Claude Bernard (1813-1878)
"Progress is achieved by exchanging our theories for new ones which go further than the old, until we find one based on a larger number of facts. ... Theories are only 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."
— Claude Bernard (1813-1878)
"Experiment is fundamentally only induced observation."
— Claude Bernard (1813-1878)
"We achieve more than we know. We know more than we understand. We understand more than we can explain."
— Claude Bernard (1813-1878)
"The stability of the internal medium is a primary condition for the freedom and independence of certain living bodies in relation to the environment surrounding them."
— Claude Bernard (1813-1878)
"The joy of discovery is certainly the liveliest that the mind of man can ever feel."
— Claude Bernard (1813-1878)
"But while I accept specialization in the practice, I reject it utterly in the theory of science."
— Claude Bernard (1813-1878)
"Men who have excessive faith in their theories ... make poor observations, because they choose among the results of their experiments only what suits their object, neglecting whatever is unrelated to it and carefully setting aside everything which might tend toward the idea they wish to combat."
— Claude Bernard (1813-1878)
"Tout est poison, rien n'est poison, tout est une question de dose."
"Everything is poisonous, nothing is poisonous, it is all a matter of dose."
— Claude Bernard (1813-1878)
"If I had to define life in a single phrase, I should clearly express my thought of throwing into relief one characteristic which, in my opinion, sharply differentiates biological science. I should say: life is creation."
— Claude Bernard (1813-1878)
"Real science exists, then, only from the moment when a phenomenon is accurately defined as to its nature and rigorously determined in relation to its material conditions, that is, when its law is known. Before that, we have only groping and empiricism."
— Claude Bernard (1813-1878)