From Mersch, Maritain and Mystical Theology by Jim Arraj - extensive quote would normally be unfair use but I'm certain Jim won't mind
Despite the fact that the idea of a spiritual unconscious was implicit in many of the things that the medieval theologians said, there was a distinct tendency to view the human spirit as identical with what we would today call ego consciousness with its ability to know and will. Maritain saw that a wider view of the human spirit could provide a solution to the apparent paradoxes surrounding the humanity of Jesus. He hypothesized that Jesus had a normal ego consciousness, as well as a spiritual unconscious, that is, the normal human depths of the soul. But he also had what could be called a supernatural unconscious. If this were so, then it was possible to reason that Jesus in his ego consciousness, as well as in his human spiritual unconscious, did not possess a fullness of grace or the beatific vision. He grew in knowledge, learned by experience, and increased in grace. But in his supernatural unconscious he did have a clear awareness of himself as the second person of the Trinity, and between these two realms there was a translucent partition.
Maritain in his book begins the delicate task of trying to discern how the light from Jesus' supernatural unconscious effected the lower regions of his soul. The soul of Jesus is composed of ordinary ego consciousness, as well as an infraconscious equivalent to a Freudian-style unconscious, and a "natural preconscious" or natural "supraconscious of the spirit." (1) In addition, it will have a unique "supraconscious of the spirit divinized in Christ by the beatific vision." (2) Thus, Jesus had in his human nature two different states of consciousness: an ordinary "world of consciousness" embracing ego consciousness, the infraconscious, and the natural supraconscious or spiritual unconscious, and he had a divinized supraconscious that was "for Him a consciousness of self" which did not only show Jesus "the holy Trinity and His own divinity... but show to Him also, - although not by reflection on His acts, -that His own Person, the divine Word, was the Self from which all the acts produced by His human faculties proceeded..." (3)
There was a certain communication between these states, as well as "a certain incommunicability," (4) a translucent partition. There was no way that the transconceptual knowledge of the beatific vision that dwelled in the heaven of Jesus' soul could express itself directly in his world of consciousness, but it did enter there "by mode of general influx and of comforting, and of participated light." (5) And Jesus in his prayer, in his infused contemplation, entered into this divinized supraconscious of his soul.
Let's turn now to Mersch. He is the heir, as well, to St. Thomas and the philosophical and theological tradition that flow from him. When Mersch uses the word consciousness, he is using it in an ontological sense much more often than in a phenomenological or psychological way. Consciousness, then, is an intrinsic dimension of being. In God it is identical with his being, and the human consciousness of Jesus is "the first principle of the supernatural order." And this consciousness must become the "consciousness of our consciousness, as we have seen.
But when Mersch examines revelation in relationship to the Trinity, he focuses more directly on the kind of psychological consciousness that Jesus had of himself. Jesus "really has a human consciousness" which "has various aspects: it is empirical, pure, infused, and beatific." (6) While there is one person or ultimate subject in Jesus who is conscious, this one person "is expressed by a two-fold consciousness," one divine and one human, "and the latter may be multiple."
"The same is true with regard to the word "I"." We must acknowledge that there are in Christ two interior expressions in which the conscious person utters Himself. In this sense there is a two-fold "I"; and indeed, the human "I" in Christ is expressed in several different ways, and to that extent is multiple." (7)
And this is the reality that Maritain is trying to explore with his ideas on the spiritual unconscious and supernatural unconscious. The human consciousness of Jesus expressed the Word in a human way "in order that the "I" it expressed might be truly its "I."" (8) Mersch realizes that "a supernatural perfection can escape the awareness even of a consciousness divinized by grace." (9) But when he is considering the human consciousness of Jesus, the question that occupied Maritain was not in the forefront of his mind. What Mersch is doing in these pages is demonstrating how the human consciousness of Jesus must have awareness of his union with the Word. He is showing that the very Incarnation which creates the entity of union in the humanity of Jesus is the ontological foundation for the human consciousness Jesus has of being the Word of God. In doing so he clarifies the theological foundations for what Maritain is trying to accomplish. Given the fact that Jesus must have a human consciousness that expresses the reality of being the second person of the Trinity, how do we reconcile that consciousness with that other dimension of human consciousness in which he learns and experiences the human joys and sorrows that are so much a part of our lives? We have seen how Maritain began to develop a solution, and Mersch moves in the same direction. He recoils from the thought that the human development of Jesus was some "kind of sport for Him." (10) "As far as His empirical consciousness is concerned, therefore, we can conceive that a real progress could have been made in the explicit formulation of the knowledge He had in His soul, and that His questions and expressions of astonishment corresponded to a very natural advance in His knowledge." (11) But this issue, as I mentioned, was not something that preoccupied him, and he does not develop it.
By now we can begin to see the convergence of Mersch's more theological approach with Maritain's analysis of the various dimensions of the consciousness of Jesus. Mersch's entity of union with its trinitarian character and the knowledge that arises from it is a theological description of what Maritain is calling the effect of the beatific vision in the divinized supraconscious of Jesus. In that heaven of the soul, Jesus is aware of himself as the Word of God, and shares in the trinitarian life. His ordinary consciousness ascends and passes through the translucent partition and enters into that heaven of the soul in his times of infused contemplation. Any theology of contemplation or Christian mystical experience, therefore, must be founded on the model of Jesus' own contemplation, and will be a participation in it.
Not only is contemplation a participation in the human consciousness of Jesus, it must in some way bear a trinitarian imprint. If Mersch's and Maritain's speculations are correct, they should be confirmed by the experience of the Christian mystics, and we should be able to find among them an experience that would be equivalent to Mersch's entity of union as participated by Christians in the divinized supraconscious of the soul of Jesus. Maritain, in the concluding pages of his Degrees of Knowledge, shows us where to look: the state of spiritual marriage described by John of the Cross. The soul of the advanced mystic is transformed in a special and definitive way by love so that "there are two natures in one spirit and love of God." (12) This is an anticipation of the beatific life in which "the soul is in some manner the Whole, the very infinity of God's life which erupts in it as if the whole sea were to flow into a river, I mean a river of love surging with vital operations and able from its very source to become one single spirit with the sea." (13)
In some mysterious way the soul in this state of spiritual marriage is associated with the operations of the Trinity. "The Holy Spirit, in producing in it a "most delicate touch and feeling of love" (which is this breathing, by which it "may love God perfectly"), raises the soul so that "she may breathe in God the same breath of love that the Father breathes in the Son and the Son in the Father, which is this same Holy Spirit that they breathe into her in the said transformation."" (14) Maritain comments on these views of John of the Cross: "It is very remarkable and of the greatest consequences that, at the summit of the spiritual life and of mystical experience the soul emerges expressly into the depths of the holiest mystery of Christian revelation, "transformed in the flame of love, wherein Father, Son and Holy Spirit commune with it."" (15)
This state is the foretaste in the soul of the mystic of the life of heaven and a participation in knowledge and love in the human consciousness of Jesus, which lives With the life of the Son and through the Son that of the Father and the Holy Spirit.
The divinized supraconscious of Jesus was where He experienced the fundamental fact that He was the very person of the Word and shared in the life of the Trinity. It was this world He entered and experienced in His infused contemplation.
"And at the moment of the Agony and of the Passion He can no longer enter there, He is barred from it by uncrossable barriers, this is why He feels himself abandoned. That has been the supreme exemplar of the night of the spirit of the mystics, the absolutely complete night. The whole world of the Vision and of the divinized supraconscious was there, but He no longer experienced it at all through His infused contemplation. And likewise the radiance and the influx of this world on the entire soul were more powerful than ever, but were no longer seized at all by the consciousness, nor experienced." (16)
What we have here is not yet a theology of Christian mystical experience, but the theological foundation for one. This would be a thoroughgoing Christocentric mystical theology resting on Mersch's vision of the mystical body and Maritain's ideas on the spiritual unconscious.