the force of the vegetative soul, as to be nourished, and to
grow--sometimes by reason of the sensitive part, as to see and hear,
to imagine and remember, to desire and to be angry. Now between these
operations there is a difference. For the operations of the sensitive
soul are to some extent obedient to reason, and consequently they are
somewhat rational and human inasmuch as they obey reason, as is clear
from the Philosopher (Ethic. i, 13). But the operations that spring
from the vegetative soul, or from the nature of elemental bodies, are
not subject to reason; consequently they are nowise rational; nor
simply human, but only as regards a part of human nature. Now it was
said (A. 1) that when a subordinate agent acts by its own form, the
operations of the inferior and of the superior agent are distinct;
but when the inferior agent acts only as moved by the superior agent,
then the operation of the superior and the inferior agent is one.

And hence in every mere man the operations of the elemental body and
of the vegetative soul are distinct from the will's operation, which
is properly human; so likewise the operations of the sensitive soul
inasmuch as it is not moved by reason; but inasmuch as it is moved by
reason, the operations of the sensitive and the rational part are the
same. Now there is but one operation of the rational part if we
consider the principle of the operation, which is the reason and the
will; but the operations are many if we consider their relationship
to various objects. And there were some who called this a diversity
of things operated rather than of operations, judging the unity of
the operation solely from the operative principle. And it is in this
respect that we are now considering the unity and plurality of
operations in Christ.

Hence in every mere man there is but one operation, which is properly
called human; but besides this there are in a mere man certain other
operations, which are not strictly human, as was said above. But in
the Man Jesus Christ there was no motion of the sensitive part which
was not ordered by reason. Even the natural and bodily operations
pertained in some respects to His will, inasmuch as it was His will
"that His flesh should do and suffer what belonged to it," as stated
above (Q. 18, A. 5). Much more, therefore, is there one
operation in Christ, than in any other man whatsoever.

Reply Obj. 1: The operations of the sensitive and nutritive
parts are not s