Friendship is unnecessary, like philosophy like art... It has no survival value; rather it is one of those things that give values to survival.
People love to talk but hate to listen. Listening is not merely not talking, though even that is beyond most of our powers; it means taking a vigorous, human interest in what is being told us. You can listen like a blank wall or like a splendid auditorium where every sound comes back fuller and richer.