The world is a dangerous place to live; not because of the people who are evil, but because of the people who don't do anything about it.

The most beautiful gift of nature is that it gives one pleasure to look around and try to comprehend what we see.

The highest principles for our aspirations and judgments are given to us in the Jewish-Christian religious tradition.

If you feed your mind as often as you feed your stomach, then you'll never have to worry about feeding your stomach or a roof over your head or clothes on your back.

I am truly a "lone traveler" and have never belonged to my country, my home, my friends, or even my immediate family, with my whole heart.

I believe my theory of relativity to be true. But it will only be proved for certain in 1981, when I am dead.

The years of anxious searching in the dark, with their intense longing, their alternations of confidence and exhaustion and the final emergence into the light -- only those who have experienced it can understand it.