“Learning is experience. Everything else is just information.”

“Man is here for the sake of other men - above all for those upon whose smiles and well-being our own happiness depends.”

“We cannot despair of humanity, since we ourselves are human beings.”

“Wenn man zwei Stunden lang mit einem Mädchen zusammensitzt, meint man, es wäre eine Minute. Sitzt man jedoch eine Minute auf einem heißen Ofen, meint man, es wären zwei Stunden. Das ist Relativität.”

“Everything that the human race has done and thought is concerned with the satisfaction of deeply felt needs and the assuagement of pain. One has to keep this constantly in mind if one wishes to understand spiritual movements and their development. Feeling and longing are the motive force behind all human endeavor and human creation, in however exalted a guise the latter may present themselves to us.”

“Genius is 1% talent and 99% percent hard work...”

“For an idea that does not first seem insane, there is no hope.”

“A man should look for what is, and not for what he thinks should be.”

“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.”

“Sólo hay dos cosas infinitas: el universo y la estupidez del hombre.”

“When you look at yourself from a universal standpoint, something inside always reminds or informs you that there are bigger and better things to worry about.”

“I am enough of an artist to draw freely upon my imagination. Imagination is more important than knowledge. Knowledge is limited. Imagination encircles the world.

“In scientific thinking are always present elements of poetry. Science and music requires a thought homogeneous.”

“Everything is energy and that's all there is. Match the frequency of the reality you want and you cannot help but get that reality. It can be no other way. This is not philosophy. This is physics.”

“The important thing is not to stop questioning. Curiosity has its own reason for existence. One cannot help but be in awe when he contemplates the mysteries of eternity, of life, of the marvelous structure of reality. It is enough if one tries merely to comprehend a little of this mystery each day. —"Old Man's Advice to Youth: 'Never Lose a Holy Curiosity.'"