Objection 1. It would seem that Christ's entire soul did not enjoy blessed fruition during the Passion. For it is not possible to be sad and glad at the one time, since sadness and gladness are contraries. But Christ's whole soul suffered grief during the Passion, as was stated above (Article 7). Therefore His whole soul could not enjoy fruition.
Objection 2. Further, the Philosopher says (Ethic. vii) that, if sadness be vehement, it not only checks the contrary delight, but every delight; and conversely. But the grief of Christ's Passion was the greatest, as shown above (Article 6); and likewise the enjoyment of fruition is also the greatest, as was laid down in the first volume of I-II, 34, 3. Consequently, it was not possible for Christ's whole soul to be suffering and rejoicing at the one time.
Objection 3. Further, beatific "fruition" comes of the knowledge and love of Divine things, as Augustine says (Doctr. Christ. i). But all the soul's powers do not extend to the knowledge and love of God. Therefore Christ's whole soul did not enjoy fruition.
On the contrary, Damascene says (De Fide Orth. iii): Christ's Godhead "permitted His flesh to do and to suffer what was proper to it." In like fashion, since it belonged to Christ's soul, inasmuch as it was blessed, to enjoy fruition, His Passion did not impede fruition.
I answer that, As stated above (Article 7), the whole soul can be understood both according to its essence and according to all its faculties. If it be understood according to its essence, then His whole soul did enjoy fruition, inasmuch as it is the subject of the higher part of the soul, to which it belongs, to enjoy the Godhead: so that as passion, by reason of the essence, is attributed to the higher part of the soul, so, on the other hand, by reason of the superior part of the soul, fruition is attributed to the essence. But if we take the whole soul as comprising all its faculties, thus His entire soul did not enjoy fruition: not directly, indeed, because fruition is not the act of any one part of the soul; nor by any overflow of glory, because, since Christ was still upon earth, there was no overflowing of glory from the higher part into the lower, nor from the soul into the body. But since, on the contrary, the soul's higher part was not hindered in its proper acts by the lower, it follows that the higher part of His soul enjoyed fruition perfectly while Christ was suffering.
Reply to Objection 1. The joy of fruition is not opposed directly to the grief of the Passion, because they have not the same object. Now nothing prevents contraries from being in the same subject, but not according to the same. And so the joy of fruition can appertain to the higher part of reason by its proper act; but grief of the Passion according to the subject. Grief of the Passion belongs to the essence of the soul by reason of the body, whose form the soul is; whereas the joy of fruition (belongs to the soul) by reason of the faculty in which it is subjected.
Reply to Objection 2. The Philosopher's contention is true because of the overflow which takes place naturally of one faculty of the soul into another; but it was not so with Christ, as was said above.
Reply to Objection 3. Such argument holds good of the totality of the soul with regard to its faculties.
Source: Summa Theologica (New Advent)