DELUSION, n.
The father of a most respectable family, comprising Enthusiasm, Affection, Self-denial, Faith, Hope, Charity and many other goodly sons and daughters.
All hail, Delusion! Were it not for thee The world turned topsy-turvy we should see; For Vice, respectable with cleanly fancies, Would fly abandoned Virtue's gross advances.
--Mumfrey Mappel
--Ambrose Bierce - The Devil's Dictionary