by the
supersubstantial Word having taken flesh integrally and truly, and
having operated and suffered whatsoever befits His human and Divine
operation." But he here mentions only one human and Divine operation,
which is written in Greek _theandrike_, i.e. God-manlike. Hence it
seems that there is but one composite operation in Christ.

Obj. 2: Further, there is but one operation of the principal and
instrumental agent. Now the human nature in Christ was the instrument
of the Divine, as was said above (Q. 7, A. 1, ad 3; Q. 8, A. 1, ad 1;
Q. 18, A. 1, ad 2). Hence the operations of the Divine and human
natures in Christ are the same.

Obj. 3: Further, since in Christ there are two natures in one
hypostasis or person, whatever pertains to the hypostasis or person
is one and the same. But operation pertains to the hypostasis or
person, for it is only a subsisting suppositum that operates; hence,
according to the Philosopher (Metaph. i, 1), acts belong to
singulars. Hence in Christ there is only one operation of the Godhead
and the Manhood.

Obj. 4: Further, as being belongs to a subsisting hypostasis, so also
does operation. But on account of the unity of hypostasis there is
only one operation of the Godhead and the (Q. 17, A. 2). Hence, on
account of the same unity, there is one operation in Christ.

Obj. [5]: Further, [where there is one thing] operated there is one
operation. But the same thing was operated by the Godhead and the
Manhood, as the healing of the lepers or the raising of the dead.
Hence it seems that in Christ there is but one operation of the
Godhead and the Manhood.

_On the contrary,_ Ambrose says (De Fide ii, 8): "How can the same
operation spring from different powers? Cannot the lesser operate as
the greater? And can there be one operation where there are different
substances?"

_I answer that,_ As was said above (Q. 18, A. 1), the aforesaid
heretics who placed one will in Christ placed one operation in
Christ. Now in order better to understand their erroneous opinion, we
must bear in mind that wherever there are several mutually ordained
agents, the inferior is moved by the superior, as in man the body is
moved by the soul and the lower powers by the reason. And thus the
actions and movements of the inferior principle are things operated
rather than operations. Now what pertains to the highest principle is
properly the operation; thus we say of man that to walk, which
belongs to the feet,