gulae" (here the creed itself is quite plainly
the regula), and even simply as "doctrina" or "institutio."[45] As to
the content of the _regula_, it was set forth by Tertullian in three
passages.[46] It is essentially the same as in Irenaeus. But Tertullian
already gives prominence within the _regula_ to the creation of the
universe out of nothing,[47] the creative instrumentality of the
Logos,[48] his origin before all creatures,[49] a definite theory of the
Incarnation,[50] the preaching by Christ of a _nova lex_ and a _nova
promissio regni coelorum_,[51] and finally also the Trinitarian economy
of God.[52] Materially, therefore, the advance beyond Irenaeus is already
very significant. Tertullian's _regula_ is in point of fact a
_doctrina_. In attempting to bind the communities to this he represents
them as schools.[53] The apostolic "lex et doctrina" is to be regarded
as inviolable by every Christian. Assent to it decides the Christian
character of the individual. Thus the Christian _disposition and life_
come to be a matter which is separate from this and subject to
particular conditions. In this way the essence of religion was split
up--the most fatal turning-point in the history of Christianity.

But we are not of course to suppose that at the beginning of the third
century the actual bond of union between all the Churches was a fixed
confession developed into a doctrine, that is, definitely interpreted.
This much was gained, as is clear from the treatise _de praescriptione_
and from other evidence, that in the communities with which Tertullian
was acquainted, mutual recognition and brotherly intercourse were made
to depend on assent to formulae which virtually coincided with the Roman
baptismal confession. Whoever assented to such a formula was regarded as
a Christian brother, and was entitled to the salutation of peace, the
name of brother, and hospitality.[54] In so far as Christians confined
themselves to a doctrinal formula which they, however, strictly applied,
the adoption of this practice betokened an advance. The scattered
communities now possessed a "lex" to bind them together, quite as
certainly as the philosophic schools possessed a bond of union of a real
and practical character[55] in the shape of certain briefly formulated
doctrines. In virtue of the common apostolic _lex_ of Christians the
Catholic Church became a reality, and was at the same time clearly
marked off from the heretic sects. But more