A hundred times every day I remind myself that my inner and outer life are based on the labors of others.

The only rational way of educating is to be an example. If one can't help it, a warning example.

Intelligence is not the ability to store information, but to know where to find it.

Many of the things you can count, don't count. Many of the things you can't count, really count.

It is only to the individual that a soul is given. And the high destiny of the individual is to serve rather than to rule, or to impose himself in any other way.

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

All the fifty years of conscious brooding have brought me no closer to answer the question, "What are light quanta?" Of course today every rascal thinks he knows the answer, but he is deluding himself.