Considered logically this concept is not identical with the totality of sense impressions referred to; but it is an arbitrary creation of the human (or animal) mind.

Everybody should be ashamed who uses the wonders of science and engineering without thinking and having mentally realized not more of it than a cow realizes of the botany of the plants which it eats with pleasure.

A life directed chiefly toward the fulfillment of personal desires will sooner or later always lead to bitter disappointment.

One ought to be ashamed to make use of the wonders of science embodied in a radio set, the while appreciating them as little as a cow appreciates the botanic marvels in the plants she munches.

The world needs heroes and it's better they be harmless men like me than villains like Hitler

The greatest activity of which man is capable: Opening up yet another fragment of the frontier of beauty.

The pursuit of knowledge for its own sake, an almost fanatical love of justice and the desire for personal independence -- these are the features of the Jewish tradition which make me thank my stars that I belong to it.