"It is what we know already that often prevents us from learning."
"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"
3 likes
Source: Claude Bernard, Henry Copley Greene (1957). “An Introduction to the Study of Experimental Medicine”, p.38, Courier Corporation
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."