A problem defined, is a problem half solved.

It is just as important to make knowledge live and keep it alive as to solve specific problems.

The daily struggle does not arise from a purpose or a program, but from an immediate need.

You cannot prevent and prepare for war at the same time.

Imagination is more important than knowledge. Knowledge is limited. Imagination encircles the world.

Nothing that I can do or say will change the structure of the universe. But maybe, by raising my voice, I can help the greatest of all causes — good will among men and peace on earth.

Concerning matter, we have been all wrong. What we have called matter is energy, whose vibration has been so lowered as to be perceptible to the senses. There is no matter.