“L'interesse per l'uomo in se stesso e per il suo destino deve sempre costituire l'obiettivo primario di tutti gli sforzi compiuti in campo tecnologico [...] affinché le creazioni della nostra mente possano rappresentare un bene e non una maledizione per l'umanità. Non scordatevelo mai, mentre siete alle prese con diagrammi ed equazioni." (dal discorso tenuto nel 1931 agli studenti del California Institute of Technology)”

“The state was made for man, not man for state.”

“A table, a chair, a bowl of fruit and a violin; what else does a man need to be happy?”

“I speak to everyone in the same way, whether he is the garbage man or the president of the university.”

“The most beautiful thing we can experience is the mysterious. It is the source of all true art and science. He to whom the emotion is a stranger, who can no longer pause to wonder and stand wrapped in awe, is as good as dead —his eyes are closed. The insight into the mystery of life, coupled though it be with fear, has also given rise to religion. To know what is impenetrable to us really exists, manifesting itself as the highest wisdom and the most radiant beauty, which our dull faculties can comprehend only in their most primitive forms—this knowledge, this feeling is at the center of true religiousness.”

“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.”

“Die Welt wird nicht bedroht von den Menschen, die böse sind, sondern von denen, die das Böse zulassen.”

“The most incomprehensible thing about the universe is that it is comprehensible.

“The future is not a gift-it is an achievement.”

“Imagination is everything”

“In the temple of science are many mansions, and various indeed are they that dwell therein and the motives that have led them thither. Many take to science out of a joyful sense of superior intellectual power; science is their own special sport to which they look for vivid experience and the satisfaction of ambition; many others are to be found in the temple who have offered the products of their brains on this altar for purely utilitarian purposes. Were [someone to] drive all the people belonging to these two categories out of the temple, the assemblage would be seriously depleted, but there would still be some men, of both present and past times, left inside. Our Planck is one of them, and that is why we love him.”

“Any fool can know. The point is to understand.”

“I am by heritage a Jew, by citizenship a Swiss, and by makeup a human being, and only a human being, without any special attachment to any state or national entity whatsoever.”

“That deep emotional conviction of the presence of a superior reasoning power, which is revealed in the incomprehensible universe, forms my idea of God.”

“Strange is our situation here on Earth. Each of us comes for a short visit, not knowing why, yet sometimes seeming to divine a purpose. From the standpoint of daily life, however, there is one thing we do know: that man is here for the sake of other men - above all for those upon whose smiles and well-being our own happiness depends.”