It is the theory that decides what we can observe.

I never came upon any of my discoveries through the process of rational thinking.

When I examine myself and my methods of thought, I come to the conclusion that the gift of fantasy has meant more to me than any talent for abstract, positive thinking.

The most beautiful experience we can have is the mysterious. It's the fundamental emotion which stands at the cradle of true art and science. Whoever does not know it can no longer wander, no longer marvel, is as good as dead, and his eyes are dimmed. The most beautiful thing we can experience is the mysterious.
It is the source of all art and science.

Few people are capable of expressing with equanimity opinions which differ from the prejudices of their social environment. Most People are even incapable of forming such opinions.

Never underestimate your own ignorance.

Nothing in the world makes people so afraid as the influence of independent-minded people.

There are only two ways to live your life. One is as though nothing is a miracle. The other is as though everything is.

When all think alike, no one thinks very much.

Common sense is the collection of prejudices acquired by age eighteen.

Weakness of attitude becomes weakness of character.

A human being is part of a whole, called by us the Universe, a part limited in time and space. He experiences himself, his thoughts and feelings, as something separated from the rest--a kind of optical delusion of his consciousness. This delusion is a kind of prison for us, restricting us to our personal desires and to affection for a few persons nearest us. Our task must be to free ourselves from this prison by widening our circles of compassion to embrace all living creatures and the whole of nature in its beauty.

I am enough of an artist to draw freely upon my imagination. Imagination is more important than knowledge. Knowledge is limited. Imagination encircles the world.

The ideals which have lighted my way, and time after time have given me new courage to face life cheerfully, have been Kindness, Beauty, and Truth. The trite subjects of human efforts, possessions, outward success, luxury have always seemed to me contemptible.

Reading, after a certain age, diverts the mind too much from its creative pursuits. Any man who reads too much and uses his own brain too little falls into lazy habits of thinking.

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.

We should take care not to make the intellect our god; it has, of course, powerful muscles, but no personality.

Reality is merely an illusion, albeit a very persistent one.

Try not to become a man of success but rather to become a man of value.

Everything should be made as simple as possible, but not one bit simpler.

If the facts don't fit the theory, change the facts.

Insanity: doing the same thing over and over again and expecting different results.

Not everything that can be counted counts, and not everything that counts can be counted.

When you are courting a nice girl an hour seems like a second. When you sit on a red-hot cinder a second seems like an hour. That's relativity.

In the middle of difficulty lies opportunity.

Great spirits have always found violent opposition from mediocrities. The latter cannot understand it when a man does not thoughtlessly submit to hereditary prejudices but honestly and courageously uses his intelligence.

The whole of science is nothing more than a refinement of everyday thinking.

Gravitation cannot be held responsible for people falling in love.

He to whom this emotion is a stranger, who can no longer pause to wonder and stand rapt in awe, is as good as dead: his eyes are closed.

Peace cannot be achieved through violence, it can only be attained through understanding.

If I have seen farther than others, it is because I was standing on the shoulders of giants.

Any intelligent fool can make things bigger, more complex, and more violent. It takes a touch of genius -- and a lot of courage -- to move in the opposite direction.

If we knew what we were doing, it wouldn't be called research, would it?