ithout being themselves generated or
corrupted, but by reason of the generation or corruption of the
"composite"; since even forms have not being, but composites have
being through forms: for, according to a thing's mode of being, is
the mode in which it is brought into being. Since, then, like is
produced from like, we must not look for the cause of corporeal forms
in any immaterial form, but in something that is composite, as this
fire is generated by that fire. Corporeal forms, therefore, are
caused, not as emanations from some immaterial form, but by matter
being brought from potentiality into act by some composite agent. But
since the composite agent, which is a body, is moved by a created
spiritual substance, as Augustine says (De Trin. iii, 4, 5), it
follows further that even corporeal forms are derived from spiritual
substances, not emanating from them, but as the term of their
movement. And, further still, the species of the angelic intellect,
which are, as it were, the seminal types of corporeal forms, must be
referred to God as the first cause. But in the first production of
corporeal creatures no transmutation from potentiality to act can
have taken place, and accordingly, the corporeal forms that bodies
had when first produced came immediately form God, whose bidding
alone matter obeys, as its own proper cause. To signify this, Moses
prefaces each work with the words, "God said, Let this thing be," or
"that," to denote the formation of all things by the Word of God,
from Whom, according to Augustine [*Tract. i. in Joan. and Gen. ad
lit. i. 4], is "all form and fitness and concord of parts."

Reply Obj. 1: By immaterial forms Boethius understands the types of
things in the mind of God. Thus the Apostle says (Heb. 11:3): "By
faith we understand that the world was framed by the Word of God;
that from invisible things visible things might be made." But if by
immaterial forms he understands the angels, we say that from them
come material forms, not by emanation, but by motion.

Reply Obj. 2: Forms received into matter are to be referred, not to
self-subsisting forms of the same type, as the Platonists held, but
either to intelligible forms of the angelic intellect, from which
they proceed by movement, or, still higher, to the types in the
Divine intellect, by which the seeds of forms are implanted in
created things, that they may be able to be brought by movement
into act.

Reply Obj. 3: The heavenly bodies