Did He have omnipotence simply?
No. Omnipotence belongs to the Creator, and not to anything created. Christ’s soul is created, and omnipotence, which is proper only to God cannot be proper to a human soul, even though that soul exists in the Person of God. We must retain the distinction in natures in the one Person of Christ.
St. Thomas’ words: “Christ’s omnipotence flows from the Divine Nature. Therefore, since the soul of Christ is a part of human nature, it cannot possibly have omnipotence.”
“By union with the Person, the Man receives omnipotence in time, which the Son of God had from eternity; the result of which union is that as the Man is said to be God, so is He said to be omnipotent.” When we get to Question 16, we will be able to better answer what it means to say “Man is God” and “God is Man” when speaking of the Incarnation.
Did He have omnipotence with regard to corporeal creatures?
No. As stated above (in the actual article, not my summary) omnipotence and perfect knowledge differ. Christ could know all things yet not have, per His human soul, power over all things, even those created. We must remember the question is about Christ’s human soul, not about His divine Person.
“All power is given to Me in heaven and on earth” He says, but He says this as the Incarnate Person, the Second Person of the Holy Trinity. Again, Question 16 will clarify all this more deeply.
Did He have omnipotence with regard to His own body?
Again, no, because His own body is part of creation, and so there is, in respect to the nature proper to His soul, no substantial difference from the last article (above). His body is a corporal creature, if you will.
It is written in Hebrews 2:17 that “it behooved Him in all things to be made like unto His brethren.” It belongs to the condition of human nature that the health of the body and its nourishment and growth are not subject to the bidding of reason or will. Otherwise, for example, if we willed to eat, we would not be hungry. (I am reminded here of the long exposition in the Summa Contra Gentiles III on how this relates to our end as one not primarily of the will, but of the intellect).
Thomas mentions here that man has three states: innocence, sin, and glory. Often we fail to realize this and think of only two states: one of sin, and one of our unfallen nature, as if after redemption we simply return to this first state. This is not the place to get into deep discussion of this issue, but it will follow from our redemption and state of eternal glory.
As the liturgy say, “oh happy fault,” and this would be pointless if we merely returned to what we should have already had by nature at our original creation. (again, I digress)
Did He have omnipotence as regards the execution of His own will?
In answering, it is best here to simply quote St. Thomas verbatim: “Christ’s soul willed things in two ways. First, what was to be brought about by Himself; and it must be said that He was capable of whatever He willed thus, since it would not befit His wisdom if He willed to do anything of Himself that was not subject to His will. Secondly, He wished things to be brought about by the Divine power, as the resurrection of His own body and such like miraculous deeds, which He could not effect by His own power, except as the instrument of the Godhead.”
Again, we must always remember the question we are answering, whether it pertains to Christ as man, Christ as God (by nature) or the One Person. I wonder at times why Question 16 was not presented earlier in the Summa, but I will humbly say it must be that I do not yet understand Thomas’ order, and not that he got it wrong. After all, the St. has said in the beginning of the Summa Contra Gentiles, (and quoting Aristotle) that “among other things that men have conceived about the wise man, the Philosopher includes the notion that ‘it belongs to the wise man to order.’”
Certainly he did such in his masterpiece.