It would be difficult to exaggerate the degree to which we are influenced by those we influence.

The aspiration toward freedom is the most essentially human of all human manifestations.

One word characterizes the most strenuous of the efforts for the advancement of science that I have made perservereingly during fifty-five years; that word is failure

The link between ideas and action is rarely direct. There is almost always an intermediate step in which the idea is overcome.

We need not only a purpose in life to give meaning to our existence but also something to give meaning to our suffering. We need as much something to suffer for as something to live for.

To the old, the new is usually bad news.

It is easier to love humanity as a whole than to love one's neighbor.