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

Our separation from each other is an optical illusion.

I am satisfied with the mystery of the eternity of life.

But the personality that finally emerges is largely formed by the environment in which a man happens to find himself during his development, by the structure of the society in which he grows up, by the tradition of that society, and by its appraisal of particular types of behavior.

Since I have introduced this term I had always a bad conscience. . . . I cannot help to feel it strongly and I am unable to believe that such an ugly thing should be realized in nature.

The led must not be compelled; they must be able to choose their own leader.

It is impossible to solve significant problems using the same knowledge that created them.