Reply Obj. 1: Christ as God and not as man was able to carry out all He wished, since as man He was not omnipotent, as stated above (Q. 13, A. 1). Nevertheless being both God and man, He wished to offer prayers to the Father, not as though He were incompetent, but for our instruction. First, that He might show Himself to be from the Father; hence He says (John 11:42): "Because of the people who stand about I have said it" (i.e. the words of the prayer) "that they may believe that Thou hast sent Me." Hence Hilary says (De Trin. x): "He did not need prayer. It was for us He prayed, lest the Son should be unknown." Secondly, to give us an example of prayer; hence Ambrose says (on Luke 6:12): "Be not deceived, nor think that the Son of God prays as a weakling, in order to beseech what He cannot effect. For the Author of power, the Master of obedience persuades us to the precepts of virtue by His example." Hence Augustine says (Tract. civ in Joan.): "Our Lord in the form of a servant could have prayed in silence, if need be, but He wished to show Himself a suppliant of the Father, in such sort as to bear in mind that He was our Teacher."
Reply Obj. 2: Amongst the other things which He knew would happen, He knew that some would be brought about by His prayer; and for these He not unbecomingly besought God.
Reply Obj. 3: To rise is nothing more than to move towards what is above. Now movement is taken in two ways, as is said De Anima iii, 7; first, strictly, according as it implies the passing from potentiality to act, inasmuch as it is the act of something imperfect, and thus to rise pertains to what is potentially and not actually above. Now in this sense, as Damascene says (De Fide Orth. iii, 24), "the human mind of Christ did not need to rise to God, since it was ever united to God both by personal being and by the blessed vision." Secondly, movement signifies the act of something perfect, i.e. something existing in act, as to understand and to feel are called movements; and in this sense the mind of Christ was always raised up to God, since He was always contemplating Him as existing above Himself. _______________________
SECOND ARTICLE [III, Q. 21, Art. 2]
Whether It Pertains to Christ to Pray According to His Sensuality?
Objection 1: It would seem that it pertains to Christ to pray according to His sensuality. For it is written (Ps. 83:3) in the person of Christ: "My heart and My flesh have rejoiced in the Living God." Now sensuality is called the appetite of the flesh. Hence Christ's sensuality could ascend to the Living God by rejoicing; and with equal reason by praying.
Obj. 2: Further, prayer would seem to pertain to that which desires what is besought. Now Christ besought something that His sensuality desired when He said (Matt. 26:39): "Let this chalice pass from Me." Therefore Christ's sensuality prayed.
Obj. 3: Further, it is a greater thing to be united to God in person than to mount to Him in prayer. But the sensuality was assumed by God to the unity of Person, even as every other part of human nature. Much more, therefore, could it mount to God by prayer.
On the contrary, It is written (Phil. 2:7) that the Son of God in the nature that He assumed was "made in the likeness of men." But the rest of men do not pray with their sensuality. Therefore, neither did Christ pray according to His sensuality.
I answer that, To pray according to sensuality may be understood in two ways. First as if prayer itself were an act of the sensuality; and in this sense Christ did not pray with His sensuality, since His sensuality was of the same nature and species in Christ as in us. Now in us the sensuality cannot pray for two reasons; first because the movement of the sensuality cannot transcend sensible things, and, consequently, it cannot mount to God, which is required for prayer; secondly, because prayer implies a certain ordering inasmuch as we desire something to be fulfilled by God; and this is the work of reason alone. Hence prayer is an act of the reason, as was said in the Second Part (II-II, Q. 83, A. 1).