Objection 1: It would seem that the soul of Christ had not this knowledge by way of comparison. For Damascene says (De Fide Orth. iii, 14): "We do not uphold counsel or choice in Christ." Now these things are withheld from Christ only inasmuch as they imply comparison and discursion. Therefore it seems that there was no collative or discursive knowledge in Christ.
Obj. 2: Further, man needs comparison and discursion of reason in order to find out the unknown. But the soul of Christ knew everything, as was said above (Q. 10, A. 2). Hence there was no discursive or collative knowledge in Him.
Obj. 3: Further, the knowledge in Christ's soul was like that of comprehensors, who are likened to the angels, according to Matt. 22:30. Now there is no collative or discursive knowledge in the angels, as Dionysius shows (Div. Nom. vii). Therefore there was no discursive or collative knowledge in the soul of Christ.
On the contrary, Christ had a rational soul, as was shown (Q. 5, A. 4). Now the proper operation of a rational soul consists in comparison and discursion from one thing to another. Therefore there was collative and discursive knowledge in Christ.
I answer that, Knowledge may be discursive or collative in two ways. First, in the acquisition of the knowledge, as happens to us, who proceed from one thing to the knowledge of another, as from causes to effects, and conversely. And in this way the knowledge in Christ's soul was not discursive or collative, since this knowledge which we are now considering was divinely infused, and not acquired by a process of reasoning. Secondly, knowledge may be called discursive or collative in use; as at times those who know, reason from cause to effect, not in order to learn anew, but wishing to use the knowledge they have. And in this way the knowledge in Christ's soul could be collative or discursive; since it could conclude one thing from another, as it pleased, as in Matt. 17:24, 25, when our Lord asked Peter: "Of whom do the kings of the earth receive tribute, of their own children, or of strangers?" On Peter replying: "Of strangers," He concluded: "Then the children are free."
Reply Obj. 1: From Christ is excluded that counsel which is with doubt; and consequently choice, which essentially includes such counsel; but the practice of using counsel is not excluded from Christ.
Reply Obj. 2: This reason rests upon discursion and comparison, as used to acquire knowledge.
Reply Obj. 3: The blessed are likened to the angels in the gifts of graces; yet there still remains the difference of natures. And hence to use comparison and discursion is connatural to the souls of the blessed, but not to angels.