Though our conduct seems so very different from that of the higher animals, the primary instincts are much alike in them and in us.

It is strange to be known so universally and yet to be so lonely.

Only six men in the world know about relativity. I am not one of them. When I ask them to explain, they confused me.

If someone feels that he has never made a mistake in his life, it only means that he has never tried anything new in his life.

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

He who finds though that lets us penetrate even a little deeper into the eternal mystery of nature has been granted great grace. He who, in addition, experiences the recognition, sympathy, and help of the best minds of his times, had been given almost more happiness than one man can bear.

The strongest force in the universe is Compound Interest.