Broken friendships can be soldered, but never sound.
— Proverbs

Treachery darkens the chain of friendship, but truth makes it brighter than ever.
— American Indian Proverbs

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

There are no rules for friendship. It must be left to itself. We cannot force it any more than love.
— William Hazlitt

In politics... shared hatreds are almost always the basis of friendships.
— Alexis de Tocqueville