"The whole of science is nothing more than a refinement of everyday thinking."

"I am enough of an artist to draw freely upon my imagination."

"What we observe as material bodies and forces are nothing but shapes and variations in the structure of space. Particles are just schaumkommen (appearances)!"

"The scientific picture of the world is a simplification, an abstraction, and it is not the whole truth."

"The world is a book, and those who do not travel read only one page."