Objection 1: It would seem that Christ did not know everything by this knowledge. For this knowledge is acquired by experience. But Christ did not experience everything. Therefore He did not know everything by this knowledge.
Obj. 2: Further, man acquires knowledge through the senses. But not all sensible things were subjected to Christ's bodily senses. Therefore Christ did not know everything by this knowledge.
Obj. 3: Further, the extent of knowledge depends on the things knowable. Therefore if Christ knew all things by this knowledge, His acquired knowledge would have been equal to His infused and beatific knowledge; which is not fitting. Therefore Christ did not know all things by this knowledge.
On the contrary, Nothing imperfect was in Christ's soul. Now this knowledge of His would have been imperfect if He had not known all things by it, since the imperfect is that to which addition may be made. Hence Christ knew all things by this knowledge.
I answer that, Acquired knowledge is held to be in Christ's soul, as we have said (Q. 9, A. 4), by reason of the active intellect, lest its action, which is to make things actually intelligible, should be wanting; even as imprinted or infused knowledge is held to be in Christ's soul for the perfection of the passive intellect. Now as the passive intellect is that by which "all things are in potentiality," so the active intellect is that by which "all are in act," as is said De Anima iii, 18. And hence, as the soul of Christ knew by infused knowledge all things to which the passive intellect is in any way in potentiality, so by acquired knowledge it knew whatever can be known by the action of the active intellect.
Reply Obj. 1: The knowledge of things may be acquired not merely by experiencing the things themselves, but by experiencing other things; since by virtue of the light of the active intellect man can go on to understand effects from causes, and causes from effects, like from like, contrary from contrary. Therefore Christ, though He did not experience all things, came to the knowledge of all things from what He did experience.
Reply Obj. 2: Although all sensible things were not subjected to Christ's bodily senses, yet other sensible things were subjected to His senses; and from this He could come to know other things by the most excellent force of His reason, in the manner described in the previous reply; just as in seeing heavenly bodies He could comprehend their powers and the effects they have upon things here below, which were not subjected to His senses; and for the same reason, from any other things whatsoever, He could come to the knowledge of yet other things.
Reply Obj. 3: By this knowledge the soul of Christ did not know all things simply, but all such as are knowable by the light of man's active intellect. Hence by this knowledge He did not know the essences of separate substances, nor past, present, or future singulars, which, nevertheless, He knew by infused knowledge, as was said above (Q. 11).