“If I had only known, I would have been a locksmith.”

“I think 99 times and find nothing. I stop thinking, swim in silence, and the truth comes to me.” 

“What really interests me is whether God had any choice in the creation of the world.”

“The tendencies we have mentioned are something new for America. They arose when, under the influence of the two World Wars and the consequent concentration of all forces on a military goal, a predominantly military mentality developed, which with the almost sudden victory became even more accentuated. The characteristic feature of this mentality is that people place the importance of what Bertrand Russell so tellingly terms “naked power” far above all other factors which affect the relations between peoples. The Germans, misled by Bismarck’s successes in particular, underwent just such a transformation of their mentality—in consequence of which they were entirely ruined in less than a hundred years. I must frankly confess that the foreign policy of the United States since the termination of hostilities has reminded me, sometimes irresistibly, of the attitude of Germany under Kaiser Wilhelm II, and I know that, independent of me, this analogy has most painfully occurred to others as well. It is characteristic of the military mentality that non-human factors (atom bombs, strategic bases, weapons of all sorts, the possession of raw materials, etc.) are held essential, while the human being, his desires and thoughts—in short, the psychological factors—are considered as unimportant and secondary. Herein lies a certain resemblance to Marxism, at least insofar as its theoretical side alone is kept in view. The individual is degraded to a mere instrument; he becomes “human materiel.” The normal ends of human aspiration vanish with such a viewpoint. Instead, the military mentality raises “naked power” as a goal in itself—one of the strangest illusions to which men can succumb.”

“I have deep faith that the principle of the universe will be beautiful and simple.”

“Student is not a container you have to fill but a torch you have to light up.”

“If this conviction had not been a strongly emotional one and if those searching for knowledge had not been inspired by Spinoza's Amor Dei Intellectualis, they would hardly have been capable of that untiring devotion which alone enables man to attain his greatest achievements.”

“If you don’t have time to do it right, when will you have time to do it over?”

“Dear Habicht, / Such a solemn air of silence has descended between us that I almost feel as if I am committing a sacrilege when I break it now with some inconsequential babble... / What are you up to, you frozen whale, you smoked, dried, canned piece of soul...?”

“Look deep, deep into nature, and then you will understand everything better. -”

“If I were not a physicist, I would probably be a musician. I often think in music. I live my daydreams in music. I see my life in terms of music.”

“There comes a time when the mind takes a higher plane of knowledge but can never prove how it got there.”

“Did you know: The only source of knowledge is experience” 

“La vie c’est comme la bicyclette : quand on arrête de pédaler on tombe.”

“Be a loner. That gives you time to wonder, to search for the truth. Have holy curiosity. Make your life worth living.”