"The holy passion of friendship is so sweet and steady and loyal and enduring in nature that it will last through a whole lifetime, if not asked to lend money."
Mark Twain
"It takes your enemy and your friend, working together, to hurt you to the heart: the one to slander you and the other to get the news to you."
Mark Twain
"Friendship often ends in love; but love in friendship - never."
Albert Camus
"The only way to have a friend is to be one."
Ralph Waldo Emerson