Science admits no exceptions; otherwise there would be no determinism — Claude Bernard

"Man can learn nothing unless he proceeds from the known to the unknown."

"In sciences of observation, man observes and reasons experimentally, but he does not experiment; and in this sense we might say that a science of observation is a passive science. In sciences of experimentation, man observes, but in addition he acts on matter, analyzes its properties and to his own advantage brings about the appearance of phenomena which doubtless always occur according to natural laws, but in conditions which nature often has not yet achieved. With the help of these active experimental sciences, man becomes an inventor of phenomena, a real foreman of creation: and under this head we cannot set limits to the power that he may gain over nature through future progress in the experimental sciences."

"The mental never influences the physical. It is always the physical that modifies the mental, and when we think that the mind is diseased, it is always an illusion."

"Considered in itself, the experimental method is nothing but reasoning by whose help we methodically submit our ideas to experience,—the experience of facts."

"A modern poet has characterized the personality of art and the impersonality of science as follows: Art is I: Science is We."

"[T]hey 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."