The heart says yes, but the mind says no.

People like you and I, though mortal of course like everyone else, do not grow old no matter how long we live.

Joy in looking and comprehending is nature's most beautiful gift.

People like us, who believe in physics, know that the distinction between past, present, and future is only a stubbornly persistent illusion.

This is too difficult for a mathematician. It takes a philosopher. The hardest thing in the world to understand is the income tax.

Unless Americans come to realize that they are not stronger in the world because they have the bomb but weaker because of their vulnerability to atomic attack, they are not likely to conduct their policy at Lake Success [the United Nations] or in their relations with Russia in a spirit that furthers the arrival at an understanding.

Most teachers waste their time by asking question which are intended to discover what a pupil does not know whereas the true art of questioning has for its purpose to discover what pupils knows or is capable of knowing.