Here the Holy Council of religious men introduces no
prior substance divided between two Persons, but the Son born of the
substance of the Father. Do we, too, deny or confess anything
else? And after other explanations of our common faith, it says,
Born not made, of one substance with the Father (which in Greek they
call ὁμοούσιον).
What occasion is there here for an erroneous interpretation? The
Son is declared to be born of the substance of the Father, not
made: lest while the word born implies His divinity, the word
made should imply He is a creature. For the same reason we have
of one substance, not to teach that there is one solitary divine
Person, but that the Son is born of the substance of God and subsists
from no other source, nor in any diversity caused by a difference of
substance. Surely again this is our faith, that He subsists from
no other source, and He is not unlike the Father. Is not the meaning here of the
word ὁμοούσιον that the
Son is produced of the Father’s nature, the essence of the Son
having no other origin, and that both, therefore, have one unvarying
essence? As the Son’s essence has no other origin, we may
rightly believe that both are of one essence, since the Son could be
born with no substance but that derived from the Father’s nature
which was its source.