To say that a man is your Friend, means commonly no more than this, that he is not your enemy. Most contemplate only what would be the accidental and trifling advantages of Friendship, as that the Friend can assist in time of need by his substance, or his influence, or his counsel. Even the utmost goodwill and harmony and practical kindness are not sufficient for Friendship, for Friends do not live in harmony merely, as some say, but in melody.

Henry David Thoreau
Another Quote

The Power Of Failure: We Get To Decide What It Means