summa-contra-gentiles

268 THE SUMMA CONTRA GENTILES
ultimate form is reached by degrees, and consequently
the more numerous will be the intermediate generations.
Wherefore in the generation of an animal or a man in
which the form is most perfect, there are many intermediate
forms and generations, and consequently corruptions, since
the generation of one is the corruption of another.^ Therefore
the vegetative soul, which comes first, when the embryo
lives the life of a plant, is corrupted, and is succeeded by a
more perfect soul which is both nutritive and sensitive, and
then the embryo lives an animal life ;
and when this is
corrupted it is succeeded by the rational soul introduced
from without :
although the preceding souls were produced
by the virtue in the semen.
Keeping these points before the mind, it is easy to answer
the objections.^
For in reply to the first objection, where it is stated that
the sensitive soul must have the same manner of origin in
man and in irrational animals, because animal is predicated
of both univocally,
— we say that this is not necessary.
Because although the sensitive souls in man and dumb
animals agree generically, they differ specifically, like the
just
things of which they are the forms. For as the animal
that is a man differs specifically from other animals in the
point of being rational, so the sensitive soul of man differs
specifically from the sensitive soul of a dumb animal in this,
that it is also intellective. Wherefore the sensitive soul in
the dumb animal has no more than the sensitive faculty,
and consequently neither its
being nor its operation is
raised above the body ;
and so it must needs be generated
together with the body, and perish when the body perishes.
On the other hand the sensitive soul in a man, through
having besides the sensitive nature an intellective power in
consequence of which it follows that it is raised above the
body both in being and in operation, is neither generated
through the generation of the body, nor perishes through
the body's corruption. Hence the different manner of
origin in the aforesaid souls is not on the part
* 3 Phys, viii. i.
"
Preceding ch.
of the