There is some self-interest behind every friendship. There is no friendship without self-interests. This is a bitter truth.

As iron sharpens iron, so a friend sharpens a friend.

Friends show their love in times of trouble, not in happiness.

A man's friendships are one of the best measures of his worth.

In friendship as well as love, ignorance very often contributes more to our happiness than knowledge.

The language of friendship is not words but meanings

True friendship can afford true knowledge. It does not depend on darkness and ignorance.

Cherish your human connections: your relationships with friends and family.

Depth of friendship does not depend on length of acquaintance.

Success always necessitates a degree of ruthlessness. Given the choice of friendship or success, I'd probably choose success.