I have not failed. I've just found 10,000 ways that won't work.

I know not with what weapons World War III will be fought, but World War IV will be fought with sticks and stones.

Only two things are infinite, the universe and human stupidity, and I'm not sure about the former.

The significant problems we face cannot be solved at the same level of thinking we were at when we created them.

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

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

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

Anyone who has never made a mistake has never tried anything new.

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

I don't believe in mathematics.

If we knew what it was we were doing, it would not be called research, would it?

Intellectuals solve problems; geniuses prevent them.

Learn from yesterday, live for today, hope for tomorrow. The important thing is to not stop questioning.

The hardest thing in the world to understand is income tax.

The important thing is not to stop questioning.

The most incomprehensible thing about the world is that it is comprehensible.

The only reason for time is so that everything doesn't happen at once.

The secret to creativity is knowing how to hide your sources.

The monotony and solitude of a quiet life stimulates the creative mind.

Blessed is the man, who having nothing to say, abstains from giving wordy evidence of the fact.

We shall not cease from exploration and the end of all our exploring will be to arrive where we started and know the place for the first time.

There is no knowledge that is not power.