 Augustine's De Civitate Dei was the basis for relating property ownership and secular justice to divine authority. Here the division between two classes of men is clear: some are members of the City of Man, motivated by love of self, while others are motivated by the love of God and a contempt for self, placing them in the City of  God.[2]  There is really only one true Lord in creation.  Mastery of one man over another is the result of Original Sin and is therefore unnatural except in the case of paternity, which is founded on parental love for a child. Among members of the City of God, the relation of prince and subject is not political and does not entail the sort of mastery we see in the City of Man, but rather involves service and sacrifice, as exemplified by the parent/child relationship.