In the primitive belief that the doubles of the dead may be induced to
yield benefits or desist from inflicting evil by bribing or cajoling or
else by threatening or coercing, we see that the modes of dealing with
ghosts broadly contrasted as antagonistic and sympathetic, initiate the
distinction between medicine man and priest.
Prompted as offerings on graves originally are by affection for the
deceased, it naturally happens that such propitiations are made more by
relatives than others. The family cult next acquires a more definite
form by the devolution of its functions on one member of the family.
Hence in ancient Egypt "it was most important that a man should have a
son established in his seat after him who should perform the due rites"
of sacrifice to his _ka_ or double. Facts also show that the devolution
of the sacrificial office accompanies devolution of property, for this
has to bear the costs of the sacrifices; and by a natural corollary the
head of the village-community combines the characters of priest and
ruler. With the increase of a chief's territory there comes an
accumulation of business which necessitates the employment of
assistants, and among the functions deputed is that of priest, at first
perhaps temporarily assumed by a brother. Such is the usual origin of
priesthood.
Many facts make it clear that, not only the genesis of polytheism but
the long survival of it are sequences of primitive ancestor-worship.
Eventually there result under favouring conditions a gravitation towards
monotheism; and with this an advance towards unification of priesthood.
The official proprietors of the deity who has come to be regarded as the
most powerful or as the possessor of all power becomes established
everywhere.
Likeness between ecclesiastical and political organisations when they
have diverged is largely due to their community of origin. There results
a hierarchy of sacerdotal functionaries analogous to the graduated
system of political functionaries; then the agencies for carrying on
celestial rule and terrestrial rule eventually begin to compete for
supremacy; and there are reasons for thinking that the change from an
original predominance of a spiritual power over the temporal power to
ultimate subjugation of it is mainly due to the development of
industrialism with the moral and intellectual changes involved.