A teacher affects eternity; he can never tell where his influence stops.

I hate photographs abstractly, because they have given me more ideas perversely and immovably wrong, than I ever should get by imagination.

A new friend is always a miracle, but at thirty-three years old, such a bird of paradise rising in the sage-brush was an avatar. One friend in a lifetime is much; two are many; three are hardly

There is no such thing as an underestimate of average intelligence.

In the one branch he most needed

American politics is a struggle, not of men but of forces. The men become every year more and more creatures of force, massed about central power houses.

I firmly believe, that before many centuries more, science will be the master of man. The engines he will have invented will be beyond his strength to control. Someday, science shall have the existence of mankind in its power, and the human race commit suicide by blowing up the world.