"It is what we know already that often prevents us from learning."
"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."
3 likes
Source: 1865 An Introduction to the Study of Experimental Medicine, vol.1, ch.1, section 3 (translated by H C Greene).
About the author
Same author
More quotes by Claude Bernard
"The experimenter who does not know what he is looking for will not understand what he finds."
"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."
"Man can learn nothing unless he proceeds from the known to the unknown."
"The terrain is everything; the germ is nothing."
"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."