obey
them as to movement. But if the motive power of a separate substance
is naturally determinate to move a certain body, that substance will
not be able to move a body of higher degree, but only one of lower
degree: thus according to philosophers the mover of the lower heaven
cannot move the higher heaven. Wherefore, since the soul is by its
nature determinate to move the body of which it is the form, it
cannot by its natural power move any other body.

Reply Obj. 2: As Augustine (De Civ. Dei x, 11) and Chrysostom (Hom.
xxviii in Matt.) say, the demons often pretend to be the souls of the
dead, in order to confirm the error of heathen superstition. It is
therefore credible that Simon Magus was deceived by some demon who
pretended to be the soul of the child whom the magician had slain.
_______________________

QUESTION 118

OF THE PRODUCTION OF MAN FROM MAN AS TO THE SOUL
(In Three Articles)

We next consider the production of man from man: first, as to the
soul; secondly, as to the body.

Under the first head there are three points of inquiry:

(1) Whether the sensitive soul is transmitted with the semen?

(2) Whether the intellectual soul is thus transmitted?

(3) Whether all souls were created at the same time?
_______________________

FIRST ARTICLE [I, Q. 118, Art. 1]

Whether the Sensitive Soul Is Transmitted with the Semen?

Objection 1: It would seem that the sensitive soul is not transmitted
with the semen, but created by God. For every perfect substance, not
composed of matter and form, that begins to exist, acquires existence
not by generation, but by creation: for nothing is generated save
from matter. But the sensitive soul is a perfect substance, otherwise
it could not move the body; and since it is the form of a body, it is
not composed of matter and form. Therefore it begins to exist not by
generation but by creation.

Obj. 2: Further, in living things the principle of generation is the
generating power; which, since it is one of the powers of the
vegetative soul, is of a lower order than the sensitive soul. Now
nothing acts beyond its species. Therefore the sensitive soul cannot
be caused by the animal's generating power.

Obj. 3: Further, the generator begets its like: so that the form of
the generator must be actually in the cause of generation. But
neither the sensitive soul itself nor any part thereof is actually in
the semen, for no part of the sensitive soul is elsewhere than i