“When a man is sufficiently motivated, discipline will take care of itself.”

“Conviction is a good motive, but a bad judge.”

“We should take care not to make the intellect our god; it has, of course, powerful muscles, but no personality. ”

“I maintain that the cosmic religious feeling is the strongest and noblest motive for scientific research.”

“It is every man's obligation to put back into the world at least the equivalent of what he takes out of it.”

“I do not believe in the God of theology who rewards good and punishes evil. My God created laws that take care of that. His universe is not ruled by wishful thinking, but by immutable laws.”

“When I was a fairly precocious young man I became thoroughly impressed with the futility of the hopes and strivings that chase most men restlessly through life. Moreover, I soon discovered the cruelty of that chase, which in those years was much more carefully covered up by hypocrisy and glittering words than is the case today. By the mere existence of his stomach everyone was condemned to participate in that chase. The stomach might well be satisfied by such participation, but not man insofar as he is a thinking and feeling being.”