would be rash to attempt to solve them _en bloc_.
Probably there is a different answer in each particular case, and I am
afraid that some cases must always remain unsolved. We may speak of
"vespers of Isis" or of a "eucharist of Mithra and his companions," but
only in the same sense as when we say "the vassal princes of the empire" or
"Diocletian's socialism." These are tricks of style used to give prominence
to a similarity and to establish a parallel strongly and closely. A word is
not a demonstration, and we must be careful not to infer an influence from
an analogy. Preconceived notions are always the most serious obstacles to
an exact knowledge of the past. Some modern writers, like the ancient
Church Fathers, are fain to see a sacrilegious parody inspired by the
spirit of lies in the resemblance between the mysteries and the church
ceremonies. Other historians seem disposed to agree with the Oriental
priests, who claimed priority for their cults at Rome, and saw a plagiarism
of their ancient rituals in the Christian ceremonies. It would appear that
both are very much mistaken. Resemblance does not necessarily presuppose
imitation, and frequently a similarity of ideas and practices must be
explained by common origin, exclusive of any borrowing. {xix}

An illustration will make my thought clearer. The votaries of Mithra
likened the practice of their religion to military service. When the
neophyte joined he was compelled to take an oath (_sacramentum_) similar to
the one required of recruits in the army, and there is no doubt that an
indelible mark was likewise branded on his body with a hot iron. The third
degree of the mystical hierarchy was that of "soldier" (_miles_).
Thenceforward the initiate belonged to the sacred militia of the invincible
god and fought the powers of evil under his orders. All these ideas and
institutions are so much in accord with what we know of Mazdean dualism, in
which the entire life was conceived as a struggle against the malevolent
spirits; they are so inseparable from the history even of Mithraism, which
always was a soldiers' religion, that we cannot doubt they belonged to it
before its appearance in the Occident.

On the other hand, we find similar conceptions in Christianity. The society
of the faithful--the term is still in use--is the "Church Militant." During
the first centuries the comparison of the church with an army was carried
out even in details;[5] the baptism of the neoph