“Do not laugh at me for writing you without having anything sensible to say. But I am so enraged by the base manner in which the public is presently daring to concern itself with you that I absolutely must give vent to this feeling. I am impelled to tell you how much I have come to admire your intellect, your drive, and your honesty, and that I consider myself lucky to have made your personal acquaintance in Brussels. Anyone who does not number among these reptiles is certainly happy, now as before, that we have such personages among us as you, and Langevin too, real people with whom one feels privileged to be in contact. If the rabble continues to occupy itself with you, then simply don't read that hogwash, but rather leave it to the reptile for whom it has been fabricated.”

“I feel compelled to say something else to you. There has been a certain ill-feeling between us the cause of which I do not want to analyze. I have struggled against the feeling of bitterness attached to it, with complete success. I think of you again with unmixed geniality and ask you to try to do the same with me. It is a shame when two real fellows who have extricated themselves somewhat from this shabby world do not afford each other mutual pleasure.”

“I am not more gifted than the average human being. If you know anything about history, you would know that is so--what hard times I had in studying and the fact that I do not have a memory like some other people do… I am just more curious than the average person and I will not give up on a problem until I have found the proper solution. This is one of my greatest satisfactions in life--solving problems--and the harder they are, the more satisfaction do I get out of them. Maybe you could consider me a bit more patient in continuing with my problem than is the average human being. Now, if you understand what I have just told you, you see that it is not a matter of being more gifted but a matter of being more curious and maybe more patient until you solve a problem.”

“I received your letter of June 10th. I have never talked to a Jesuit priest in my life and I am astonished by the audacity to tell such lies about me. From the viewpoint of a Jesuit priest I am, of course, and have always been an atheist.”

“It was, of course, a lie what you read about my religious convictions, a lie which is being systematically repeated. I do not believe in a personal God and I have never denied this but have expressed it clearly. If something is in me which can be called religious then it is the unbounded admiration for the structure of the world so far as our science can reveal it.”

“The finest emotion of which we are capable is the mystic emotion. Herein lies the germ of all art and all true science. Anyone to whom this feeling is alien, who is no longer capable of wonderment and lives in a state of fear is a dead man. To know that what is impenetrable for us really exists and manifests itself as the highest wisdom and the most radiant beauty, whose gross forms alone are intelligible to our poor faculties – this knowledge, this feeling … that is the core of the true religious sentiment. In this sense, and in this sense alone, I rank myself among profoundly religious men.”

“Every day I remind myself that my inner and outer life are based on the labors of other men, living and dead, and that I must exert myself in order to give in the same measure as I have received and am still receiving.”