Grotstein offers "a model of the psyche in which there is a phenomenal subject (our conscious experience of ourselves as 'I') and an 'Ineffable Subject of the Unconscious.' The latter term is intentionally ambiguous in that it represents a subject who is a reflection of itself and is known (and knows itself) only indirectly... psychological health might be thought of as the degree to which an individual has been able to create a generative tension between the phenomenal subject and the Ineffable Subject of the Unconscious.

...the mystery of dreaming... is a critical way we have of communicating with ourselves and of processing that unconscious communication in the very act of dreaming. The remembering of dreams and their verbal narration in the analytic setting are secondary and tertiary phenomena. The dreamer who dreams the dream works in concert with the dreamer who understands the dream in their effort to give visual, narrative shape to psychic pain that can be viewed by an internal audience. That audience (the dreamer who understands the dream) understands and bears therapeutic witness to the truth of the experience that is brought to life in the experience of dreaming. This internal therapeutic dialogue, like the stars in the sky, is continuous, but visible only at night (that is, in sleep). The dreamer, never represented in the dream, is the 'Ineffable Subject of the Unconscious.' In this context, the Ineffable Subject of the Unconscious might be understood as a quality of being that is forever creating metaphoric reflections of itself: Dreams are among its most creative, magnificent, terrifying, enigmatic, unlocalizable creations. It could be said that we are most fully ourselves in the dreaming of the dreams that dream us...

The analytic quest... involves the voluntary 'unconcealment' of private, pain-ridden aspects of self. To achieve this, the Ineffable Subject of the Unconscious and the phenomenal subject join in an effort in which the Ineffable Subject of the Unconscious serves as a metaphorical 'playwright of the analytic text.' The Ineffable Subject of the Unconscious communicates (in the form of symptoms, dreams, actings-in, actings-out and so on) to the phenomenal subject formerly unexpressed and inexpressible pain. The phenomenal subject brings to the Ineffable Subject of the Unconscious the pain of current life experience (which is saturated with its historical antecedents). The Ineffable Subject of the Unconscious 'reworks' current experience, for example, in the form of dreaming, and tus makes it available in its altered form to the phenomenal subject..."

Also,

"Bion believed that the most basic driving force for human beings was not the Freudian libidinal and aggressive drives or the Kleinian death instinct, but the 'truth instinct' that involves an ability to achieve a resonance with 'O.' O is the symbol Bion used to refer to 'ultimate Truth,' which is unknowable in any direct way. O is beyond words and beyond sensory perception. The infant has a need for Truth that is as strong as his need for food. In early development, the infant projects unbearable (unthinkalbe) truth into the mother who converts it into bits of knowledge (K), which can be used by the infant for purposes of thinking and feeling that which was formerly unbearable to think or feel. This mother-infant relationship serves as a model for Bion's conception of the analytic relationship... transference itself is ultimately directed, through the analyst as object, toward the analysand's own unconscious (the Ineffable Subject of the Unconscious). The analyst in a state of reverie (a state of receptivity free of memory or desire) attempts to live with the truth projected into him by the analysand and, in a sense, 'becomes it' before transforming it into symbols (K)..."

From "Who is the Dreamer Who Dreams the Dream?" by James S. Grotstein