Strive not to be a success, but rather to be of value.

[Freud's] sense of reality is less clouded by wishful thinking than is the case with other people and [he combines] the qualities of critical judgment, earnestness and responsibility.

Human beings, in their thinking, feeling and acting are not free agents but are as causally bound as the stars in their motion.

No amount of experimentation can ever prove me right; a single experiment can prove me wrong.

You have to color outside the lines once in a while if you want to make your life a masterpiece.

The great need to grasp principles had caused me to spend most of my time on fruitless persuits.

It followed from the special theory of relativity that mass and energy are both but different manifestations of the same thing...