War seems to me to be a mean, contemptible thing: I would rather be hacked in pieces than take part in such an abominable business. And yet so high, in spite of everything, is my opinion of the human race that I believe this bogey would have disappeared long ago, had the sound sense of the nations not been systematically corrupted by commercial and political interests acting through the schools and the Press

Physical concepts are free creations of the human mind, and are not, however it may seem, uniquely determined by the external world.

The important thing is not to stop questioning. Curiosity has its own reason for existing. One cannot help but be in awe when he contemplates the mysteries of eternity, of life, of the marvelous structure of reality. It is enough if one tries merely to comprehend a little of this mystery every day. Never lose a holy curiosity.

What is inconceivable about the universe is that it is at all conceivable.

Student: Dr. Einstein, Aren't these the same questions as last year's [physics] final exam? Dr. Einstein: Yes; But this year the answers are different.

Imagination is greater than knowledge.

It gives me great pleasure indeed to see the stubbornness of an incorrigible nonconformist warmly acclaimed.