The human mind has first to construct forms, independently, before we can find them in things.

In quitting this strange world he has once again preceded me by a little. That doesn't mean anything. For those of us who believe in physics, this separation between past, present, and future is only an illusion, however tenacious.

You can never solve a problem on the level on which it was created.

The scientist finds his reward in what Henri Poincare calls the joy of comprehension, and not in the possibility of application to which any discovery may lead.

.. 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?

The only way to escape the personal corruption of praise is to go on working. One is tempted to stop and listen to it. The only thing is to turn away and go on working. Work. There is nothing else.

There is no salvation for civilization, or even the human race, other than the creation of a world government.