One loyal friend is worth ten thousand relatives.

Keep company only with people who uplift you, whose presence calls forth your best.

Whatever you do in life, surround yourself with smart people who'll argue with you.

A friend is as it were a second self.

You shall judge of a man by his foes as well as by his friends.

Intelligent people tend to have less friends than the average person. The smarter you are, the more selective you become.