In my personal experience I have hardly come to know the wretchedness of mankind better than as a result of the general theory of relativity and everything connected to it. But it doesn't bother me.

You see, wire telegraph is a kind of a very, very long cat. You pull his tail in New York and his head is meowing in Los Angeles. Do you understand this? And radio operates exactly the same way: you send signals here, they receive them there. The only difference is that there is no cat.

I thought of that while riding my bicycle.

It's no accident that capitalism has brought with it progress, not merely in production but also in knowledge. Egoism and competition are, alas, stronger forces than public spirit and sense of duty.

He who has never been deceived by a lie does not know the meaning of bliss.

But there is another reason for the high repute of mathematics: it is mathematics that offers the exact natural sciences a certain measure of security which, without mathematics, they could not attain.

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.