.. free and responsible development of the individual, so that he may place his powers freely and gladly in the service of all mankind. There is no room in this for the divinization of a nation, of a class, let alone of an individual. Are we not all children of one father, as it is said in religious language?

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

I sometimes ask myself how it came about that I was the one to develop the theory of relativity. The reason, I think, is that a normal adult never stops to think about problems of space and time. These are things which he has thought about as a child. Bu t my intellectual development was retarded,as a result of which I began to wonder about space and time only when I had already grown up.

Be a voice not an echo.

The more I learn of physics, the more I am drawn to metaphysics.

Although I am a typical loner in my daily life, my awareness of belonging to the invisible community of those who strive for truth, beauty, and justice has prevented me from feelings of isolation.

Scientific greatness is less a matter of intelligence than character; if the scientist refuses to compromise or accept incomplete answers and persists in grappling the most basic and difficult questions.