Concern for man himself and his fate must always form the chief interest of all technical endeavors, concern for the great unsolved problems of the organization of labor and the distribution of goods-in order that the creations of our mind shall be a blessing and not a curse to mankind. Never forget this in the midst of your diagrams and equations.

The greatest tragedy of human existence is the illusion of separateness.

A man has to work so hard so that something of his personality stays alive. A tomcat has it so easy, he has only to spray and his presence is there for years on rainy days.

Life is like riding a bicycle. To keep your balance, you must keep moving.

One strength of the communist system of the East is that it has some of the character of a religion and inspires the emotions of a religion.

How can any educated person stay away from the Greeks? I have always been far more interested in them than in science.

The consequence was a positively fanatic [orgy of] freethinking coupled with the impression that youth is being deceived by the state through lies; it was a crushing impression