apitulation
theory also suggested to him a parallel between Adam and Eve on the one
hand and Christ and Mary on the other, which included the birth from the
virgin.[583] He argues in opposition to the Valentinians that it was
really the eternal Word of God himself, who was always with God and
always present to the human race, that descended.[584] He who became man
was not a being foreign to the world--this is said in opposition to
Marcion--but the Lord of the world and humanity, the Son of God, and
none other. The reality of the body of Christ, i.e., the essential
identity of the humanity of Christ with our own, was continually
emphasised by Irenaeus, and he views the whole work of salvation as
dependent on this identity.[585] In the latter he also includes the fact
that Jesus must have passed through and been subjected to all the
conditions of a complete human life from birth to old age and
death.[586] Jesus Christ is therefore the Son of God who has really
become the Son of man; and these are not two Christs but one, in whom
the Logos is permanently united with humanity.[587] Irenaeus called this
union "union of the Word of God with the creature" ("adunitio verbi dei
ad plasma")[588] and "blending and communion of God and man" ("commixtio
et communio dei et hominis")[589] without thereby describing it any more
clearly.[590] He views it as perfect, for, _as a rule_, he will not
listen to any separation of what was done by the man Jesus and by God
the Word.[591] The explicit formula of two substances or natures in
Christ is not found in Irenaeus; but Tertullian already used it. It never
occurred to the former, just because he was not here speaking as a
theologian, but expressing his belief.[592] In his utterances about the
God-man Tertullian closely imitates Irenaeus. Like the latter he uses the
expression "man united with God" ("homo deo mixtus")[593] and like him
he applies the predicates of the man to the Son of God.[594] But he goes
further, or rather, in the interest of formal clearness, he expresses
the mystery in a manner which shows that he did not fully realise the
religious significance of the proposition, "the Son of God made Son of
man" ("filius dei filius hominis factus"). He speaks of a "corporal and
spiritual, i.e., divine, substance of the Lord", ("corporalis et
spiritalis (i.e., divina) substantia domini")[595] of "either substance
of the flesh and spirit of Christ" ("utraque substantia et carnis et
spir