"The man who has not passed through the bitter experience of doubt, has not made a single step forward in science."

"The most important task of science is to liberate man from the illusion that he is the center of the world."

"The true pioneer is a man who, if necessary, is prepared to go into the wilderness alone, without anyone following him."

"My original decision to devote myself to science was a direct result of the discovery, which has never ceased to fill me with enthusiasm, that the laws of nature are accessible to human thought."

"The world is not a machine, but a living organism."