If [quantum theory] is correct, it signifies the end of physics as a science.

One must shy away from questionable undertakings, even when they bear a high-sounding name.

We believe that an informed citizenry will act for life and not for death.

When a man, after long years of searching, chances upon a thought which discloses something of the beauty of this mysterious universe, he should not therefore be personally celebrated. He is already sufficiently paid by his experience of seeking and finding.

Energy cannot be created or destroyed, it can only be changed from one form to another.

Enough for me is the mystery of the eternity of life, and the inkling of the marvelous structure of reality. There is in this neither a will nor a goal, nor a must, but only sheer being.

I do not believe that a man should be restrained in his daily actions by being afraid of punishment after death or that he should do things only because in this way he will be rewarded after he dies. This does not make sense. The proper guidance during the life of a man should be the weight that he puts upon ethics and the amount of consideration that he has for others.