True love is like a pair of socks: you gotta have two and they've gotta match.

One cannot be deeply responsive to the world without being saddened very often.

Man may be defined as the animal that can say ''I,'' that can be aware of himself as a separate entity.

Man can never stand still. He must find solutions to this contradiction, and ever better solutions to the extent to which reality enables him.

Exclusive love is a contradiction in itself.

Human history begins with man's act of disobedience which is at the same time the beginning of his freedom and the development of his reason.

The average American is not concerned with his society. He talks about it, but you know if one speaks of being concerned, I mean something about which one loses one's sleep, sometimes.