"I consider myself a very fortunate man, because I have been able to devote my entire life to the pursuit of knowledge and the service of humanity."

"If I try to continue a broken line of thought, I feel a veritable spiritual nausea, then, almost by chance, I go over to another job, surprised by the freshness of mind and ease with which I overcome …"

"The human being is a self-propelled automaton entirely under the control of external influences. Willful and predetermined though they appear, his actions are governed not from within, but from withou…"

"I myself have made my own discoveries in the greatest solitude, and when I have been alone, undisturbed."

"A man is born to work, to suffer and to fight; he who doesn't, must perish."