“The only thing that you absolutely have to know, is the location of the library.”

“All generalizations are false, including this one.”

“It is this mythical, or rather symbolic, content of the religious traditions which is likely to come into conflict with science. This occurs whenever this religious stock of ideas contains dogmatically fixed statements on subjects which belong in the domain of science.”

“One thing I have learned in a long life: that all our science, measured against reality, is primitive and childlike -- and yet it is the most precious thing we have.”

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

“You never fail until you stop trying.”

“One should not pursue goals that are easily achieved. One must develop an instinct for what one can just barely achieve through one’s greatest efforts.”

“To know the secrets of Life, we must first become aware of their existence.”

“Your question is the most difficult in the world. It is not a question I can answer simply with yes or no. I am not an Atheist. I do not know if I can define myself as a Pantheist. The problem involved is too vast for our limited minds. May I not reply with a parable? The human mind, no matter how highly trained, cannot grasp the universe. We are in the position of a little child, entering a huge library whose walls are covered to the ceiling with books in many different tongues. The child knows that someone must have written those books. It does not know who or how. It does not understand the languages in which they are written. The child notes a definite plan in the arrangement of the books, a mysterious order, which it does not comprehend, but only dimly suspects. That, it seems to me, is the attitude of the human mind, even the greatest and most cultured, toward God. We see a universe marvelously arranged, obeying certain laws, but we understand the laws only dimly. Our limited minds cannot grasp the mysterious force that sways the constellations. I am fascinated by Spinoza's Pantheism. I admire even more his contributions to modern thought. Spinoza is the greatest of modern philosophers, because he is the first philosopher who deals with the soul and the body as one, not as two separate things.”

“Teaching should be such that what is offered is perceived as a valuable gift and not as a hard duty.”

“I was barked at by numerous dogs who are earning their food guarding ignorance and superstition for the benefit of those who profit from it. Then there are the fanatical atheists whose intolerance is of the same kind as the intolerance of the religious fanatics and comes from the same source. They are like slaves who are still feeling the weight of their chains which they have thrown off after hard struggle. They are creatures who—in their grudge against the traditional "opium of the people"—cannot bear the music of the spheres. The Wonder of nature does not become smaller because one cannot measure it by the standards of human morals and human aims.”

“MY DEAR CHILDREN: I rejoice to see you before me today, happy youth of a sunny and fortunate land. Bear in mind that the wonderful things you learn in your schools are the work of many generations, produced by enthusiastic effort and infinite labor in every country of the world. All this is put into your hands as your inheritance in order that you may receive it, honor it, add to it, and one day faithfully hand it on to your children. Thus do we mortals achieve immortality in the permanent things which we create in common. If you always keep that in mind you will find a meaning in life and work and acquire the right attitude toward other nations and ages.”

“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.”

“Matter tells space how to curve, space tells matter how to move.”

“La teoria è quando si sa tutto e niente funziona. La pratica è quando tutto funziona e nessuno sa il perché. Noi abbiamo messo insieme la teoria e la pratica: non c'è niente che funzioni... e nessuno sa il perché!”