restricted to his own tribe of Levi, and more especially the
family of his own brother Aaron.

The priestly office by its own nature is superior to the kingly,
and in all primitive nations with a separate, organized
priesthood, whether a true priesthood or a corrupt, the priest is
held to be above the king, elects or establishes the law by which
is selected the temporal chief, and inducts him into his office,
as if he received his authority from God through the priesthood.
The Christian priesthood is not a caste, and is transmitted by
the election of grace, not as with the Israelites and all
sacerdotal nations, by natural Generation. Like Him whose
priests they are, Christian priests are priests after the order
of Melchisedech, who was without priestly descent, without father
or mother of the priestly line. But in being priests after the
order of Melchisedech, they are both priests and kings, as
Melchisedech was, and as was our Lord himself, to whom was given
by his Father all power in heaven and in earth. The Pope, or
Supreme Pontiff, is the vicar of our Lord on earth, his
representative--the representative not only of him who is our
invisible High-Priest, but of him who is King of kings and Lord
of lords, therefore of both the priestly and the kingly power.
Consequently, no one can have any mission to govern in the state
any more than in the church, unless derived from God directly or
indirectly through the Pope or Supreme Pontiff. Many theologians
and canonists in the Middle Ages so held, and a few perhaps hold
so still. The bulls and briefs of several Popes, as Gregory VII.,
Innocent Ill., Gregory IX., Innocent IV., and Boniface VIII.,
have the appearance of favoring it.