Patience and tenacity of purpose are worth more than twice their weight of cleverness.
Every great advance in natural knowledge has involved the absolute rejection of authority.
Nothing can be more incorrect than the assumption one sometimes meets with, that physics has one method, chemistry another, and biology a third.
Time, whose tooth gnaws away everything else, is powerless against truth.
It is because the body is a machine that education is possible. Education is the formation of habits, a superinducing of an artificial organization upon the natural organization of the body.
The scientific imagination always restrains itself within the limits of probability.