Time is what the clock says.

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.

Every day I remind myself that my inner and outer life are based on the labors of other men, living and dead, and that I must exert myself in order to give in the same measure as I have received and am still receiving.

The most fundamental question we can ever ask ourselves is whether or not the universe we live in is friendly or hostile.

Joy and amazement of the beauty and grandeur of this world of which man can just form a faint notion.

No problem is ever solved in the same consciousness thas was used to create it.

It is difficult even to attach a precise meaning to the term "scientific truth." So different is the meaning of the word "truth" according to whether we are dealing with a fact of experience, a mathematical proposition or a scientific theory. "Religious truth" conveys nothing clear to me at all.