My mother understood human nature better and never chided. She knew that a man cannot be saved from his own foolishness or vice by someone else's efforts or protests, but only by the use of his own will.

Be alone, that is the secret of invention; be alone, that is when ideas are born.

In a time not distant, it will be possible to flash any image formed in thought on a screen and render it visible at any place desired. The perfection of this means of reading thought will create a revolution for the better in all our social relations.

Throughout the infinite, the forces are in a perfect balance, and hence the energy of a single thought may determine the motion of a universe.

A century from now it will no more occur to a normal person to mate with a person eugenically unfit than to marry a habitual criminal.

Is nature a giant cat? If so, who strokes its back?

The progressive development of man is vitally dependent on invention.