The scientific theorist is not to be envied. For Nature, or more precisely experiment, is an exorable and not very friendly judge of his work. It never says "yes" to a theory. In the most favorable cases it says "Maybe," and in the great majority of cases simply "No." If an experiment agrees with a theory it means for the latter "Maybe," and if it does not agree it means "No." Probably every theory will some day experience its "No" - most theories, soon after conception.

Man's will, sustained by an indominable conviction, is much more powerful than material forces that seem insurmountable.

The most beautiful experience in the world is the experience of the mysterious.

But the personality that finally emerges is largely formed by the environment in which a man happens to find himself during his development, by the structure of the society in which he grows up, by the tradition of that society, and by its appraisal of particular types of behavior.

Although I cannot believe that the individual survives the death of his body, feeble souls harbor such thought through fear or ridiculous egotism.

If you want different results, do not do the same things.

[Max Planck] was one of the finest people I have ever known... but he really didn't understand physics, [because] during the eclipse of 1919 he stayed up all night to see if it would confirm the bending of light by the gravitational field. If he had really understood [general relativity], he would have gone to bed the way I did