There is much in this somewhat obscure passage that stands in need of explication and elaboration. Suffice it to comment on what seems to me the most important point. Gebser sees consciousness not merely as a witnessing function but as an active or directive force. He even considers the possibilit y of consciousness being the co-initiator of the different "mutations" or structural changes. Positing himself in the mental-rational consciousness, but without stating so explicitly, he regards consciousness as mediating between the ego (at least in the mental-rational structure) and the "itself" (Sich), which is the suprapersonal spiritual reality. He even speaks of consciousness as being "bound" to the ego and the "itself" respectively.
This dual "indebtedness" of consciousness explains its tensional nature. It is a dynamic function that constantly "intends," as phenomenologists would say. But in its association with the "itself" it simultaneously transcends this intentional proclivity which is responsible for the whole play of attention. It is undoubtedly this transcending aspect of consciousness that defines its capacity as self-consciousness. Perhaps we can say that insofar as consciousness is aligned with the "itself," which is the spiritual, it assumes a witnessing function, whereas its alignment with the self-sense (either as the mental-rational ego or its pre-forms in historically more primitive structures) is generative of the intentional dynamics.

It is not difficult to see why Gebser should regard consciousness as a possible co-trigger for its own mutational changes. Elsewhere he suggests that the impulse for the mutations of consciousness may be found in the origin it self.[15]

So we may see the history of consciousness as an ultimately unfathomable in terplay between, on the one hand, an originary impulse and, on the other hand, a "genetic" readiness in human consciousness together with the momentum of the sociocultural forms created by consciousness. But with this consideration we have undeniably crossed over into metaphysics and theology. Gebser is always conscious of doing so, but never embarrassed by it. I intended to follow his example in this. Without wanting to anticipate too much of the explorations of Chapter 8, it might be useful to consider at this early stage some of the "extra-scientific" concepts that Gebser brings into play in his depiction of the structures of consciousness.
As has been noted already, Gebser distinguishes four basic psychic environments or structures of consciousness. These may be arranged chronologically, but, as he repeatedly emphasizes, together they are constitutive of the total consciousness of modern humanity. Thus, the archaic structure of consciousness, as the name suggests, historically precedes and psychically underlies, all others. It is the least complex or the least dimensionated; therefore it is also the dimmest (from the vantage point of the mental-rational consciousness). Its persistent effectiveness in us is demonstrated primarily by the phenomenon of deep sleep and secondarily by phenomena associated with myst icism. Similarly, the other structures the magical, the mythical, and the mental-rational are co-present in the human psyche, and their interplay is responsible for the mutidemensionality of human experience. Practical examples of this are given in Chapter 9.

The brightest structure is the mental consciousness, with its fully crystallized center of experiencing (the "ego"). But its brightness is the very reason that it is also the most removed from the originary presence. Not that the origin is dim. Rather, the focused luminosity of the egoic mental consciousness acts as a distraction by which the "spiritual light" which, he insists, is a "concrete fact."[16] originary radiance and here we are again approaching theology is blocked out. In Verfall und Teilhabe (Decline and Participation), Gebser writes freely of the He steadfastly refuses to equate this originary light, which is the "uncreate light" of the monks of Mount Athos or the "radiance" (jyotis) of Hindu mystics, with consciousness.
However, Gebser does speak of the "itself-consciousness" (Sich-Bewusstsein), or simply the "itself" (Sich), as both the innermost nucleus of our being and the intensity "within" us which shapes our individual destiny and which is identical to the origin. He explains:

This "core"-to use our tentative designation so as to avoid such concepts as essence, essentiality, substance, superego, self, divine spark, and the like--we should like to describe more appropriately with the term "the itself."The itself can become visible in the reflexivity of the ego, without succumbing to the autism or narcissism of a "self" and without a psychic coloration inherent in the mystical "divine spark," which shows its indebtedness to the psychic-mythical structure by virtue of the fire-spirit symbolism.[17]

Gebser continues:

. . . the itself is that which pervades or "shines through" everything and in which the diaphanous spirituality, in its originary presence, is able to become transparent.[18]

This matter, which must appear recondite to the rational consciousness, is obvious from within that structure of consciousness which Gebser toiled hardest to document: the aperspectival or arational-integral consciousness which is emerging today. This nascent structure of consciousness, for the first time in human history, permits the conscious integration of all previous (but co-present) structures, and through this act of integration t he human personality becomes, as it were, transparent to itself so that the originary presence, "the spiritual" (das Geistige), is directly "awared."
This "awaring" or unmediated perceiving is possible because the spiritual origin is not mere temporal beginning, the first member of the historical chain of consciousness mutations. Rather it is, as the title of Gebser's magnum opus indicates, ever-present and not space or time-bound. We might say it is sheer presence. In the integral structure of consciousness this fact becomes self-evident: the originary presence is "presentiated" (vergegenw‰rtigt). And this presentation of the spiritual origin enables the human being to transcend the potential exclusivity of all structures of consciousness.
Clearly, the integral event of "awaring" the spiritual reality must not be equated with a relapse into unconsciousness or, barring the use of this term, into the dimness of lesser-dimensioned types of consciousness. And this is exactly what has for centuries been claimed by the great spiritual figures of the world, who have always spoken of a "super-consciousness." For the enlightened beings of Hinduis m the atman, which can correctly be rendered as "itself," is flawless consciousness (cit) or the "witness" (s_ksin) of all contents of what could be called the conditional consciousness (citta). According to their testimony this witness-consciousness is utterly unqualified, transpersonal, absolute.
Gebser makes no such claims for his "itself." He admits to using this term, rather than the more common "self," in order to prevent the confusion of his concept with "the notions of India, the merely psychological definition by C. G. Jung, or its mental-rational misinterpretation by Buber."[19] And yet, in a little known talk published in India, Gebser uses the term atman in a way that is suggestive of the  "itself,"[20] but we must presume that he does so as a concession to what was presumably a predominantly Hindu audience. Looking at the totality of his work, I venture to propose that his concept of the "itself" and the Indian notion of atmanare possibly far more compatible than he cares to concede.
The main reason for his reluctance to speak of the spiritual or originary presence as consciousness, which is the constant reiteration of the Hindu authorities, is that he wishes to dissociate himself from the reference to "being" (Sein) contained in the German word Bewusstseinor consciousness and possible Hegelian implications.[21]

Gebser also cautions us not to hastily repeat Hegel's mistake of reading the history of consciousness as a self-actualization of world reason (Weltvernunft).[22] But, as is so often the case, he does not want to pin things (and himself) down by furnishing a precise alternative. For the same reason he tends to avoid definitions, which are perspectival fixations in the domain of language. In his writings he takes on the formidable task of trying to communicate intelligibly while not allowing himself to be hampered by the rational conventions of our language. At times this is like riding a train off its rails--an audacious, possibly foolhardy adventure, yet one that is potentially rewarding, because it radically opens up new vistas.
At other times, however, Gebser's flexibility is both a boon and a drawback. Thus his characterizations of the different structures or modalities of consciousness tend to be too summary. He focuses on their essential morphology but only marginally discusses their chronology--a weakness he shares with Oswald Spengler. This neglect is not accidental either. For instance, he writes about the magical structure of consciousness:

How far back we may wish to place this magic time into prehistory is not only a question of one's predilection, but, on account of the timeless character of the magical, is essentially an illusion, One group will tend to date it back several hundred thousand years, another will be content to place it in the postglacial period . . . It is pure speculation if we attempt to locate something timeless in a temporal framework that we have subsequently devised.[23]

The logic of Gebser's argument is manifestly spurious. Even in terms of his own multidimensional methodology, it would be perfectly legitimate to enquire into the chronology of a structure that is marked by timelessness but obviously can be located in space-time. Surely it is possible to remain sensitive to the psychic composition or structural "feel" of the magical consciousness, without having to sacrifice the mental-rational concern with time, so long as this concern is transparent to us.
It is my presumption that had Gebser shown more respect for the chronological aspect of the mate rials scrutinized by him, his portrayal of the history of human consciousness would have gained in definition. More important ly, it would have obliged him to take another look at his central notion that the different structures are sudden spontaneous mutations. For he would have had to acknowledge that there is a far greater continuity of consciousness mutations than his four-structure model permits.
Right at the beginning of his discussion of the magical structure, Gebser himself concedes that we "should perhaps interpose one or even two further structures between the archaic and the magic, such as 'post-archaic' and a 'pre-magical' structure," adding "but the material at our disposal does not furnish any decisive evidence for precise delimitations of such intermediary structures."[24] Clearly, this admission of sub-structures is founded in a recognition that there is in fact more of a continuity in the unfolding of human consciousness that his thesis of sudden mutational leaps suggests.
The reason for Gebser's rejection of a Darwinian-style evolutionary model for the unfolding of human consciousness is not far to seek. On the one hand, he wants t o avoid any implications of progress toward the mental-rational as the neutral culmination of the history of consciousness. On the other hand, he wants to emphasize the fact that this process is not determined by biological (genetic) or sociological historical factors, but by the spiritual or originary presence. (Interestingly, the German word for "origin" is Ursprung which literally means "primal leap") . Gebser contrasts these consciousness mutations with biological mutations, arguing that whereas the former are "plus mutations" which lead to structural enrichment, the latter give rise to greater functional specialization.[25]

His description of the the various structures, however, suggests major evolutionary leaps known as "saltations" rather than mutations.
While the historical and prehistorical data allow one to postulate discontinuities in the unfolding of human consciousness, it should be remembered that the available evidence is incomplete. Therefore we must at least reckon with the possibility that any apparent discontinuities may only be gaps in our knowledge. But even if that were so, Gebser's broadly phenomenological model of the history of consciousness as a "spiritually qualified process"[26]would, in principle, still be tenable.
In that case, the following explanation could be proposed: the spiritual origin, which is the perennial foundation of all spatio-temporal occurrences, exerts, by its very presence, a continuous "pressure" on space-time. Biologically, the human body-mind is most responsive to this originary "pressure," which leads to an intensification of consciousness through which the originary "pressure" gets internalized as it were. This effectively or deficiently. In the latter instance the tension elicits avoidance or reactive regression to a lower-level int ensity (or more primitive structure of consciousness). In the former instance the body-mind becomes receptive to a yet higher level of intensification of consciousness, transcending the present level and condition and establishing a new state of tension. Possibly catastrophe theory can offer a formal model for this explanation.

The idea of an "efficient" and a "deficient" response, or cycle, in a given structure of consciousness is fundamental to Gebser's work. He applies it very successfully to the contemporary situation by identifying the rational consciousness as the deficient mode of the mental structure of consciousness. He thereby undermines the great evolutionistic ideal of the Enlightenment philosophers and their epigones, according to whom ratio is the pinnacle of all human development.

An example of a creative response in this process is readily available for the mental-rational consciousness: when self- or ego-consciousness reaches a certain degree of intensity or "condensation," it inevitably becomes involved in a struggle to resolve the inherent conflict between itself and all others. It begins to develop strategies for restoring psychic harmony or equilibrium. This may be expressed in terms of a quest for new self-understanding (thus emphasizing the affective aspect). However, this struggle or search always implicates the total person, and once the quest has begun, it reveals itself as having many different dimensions. In the final analysis this search is always a movement toward self-transcendence.
On the deficient side, a person may simply seek to drown his or her felt psychic dilemma or tension in alcohol, drug abuse, sex, or even work. Indeed, this is the reaction and chosen destiny of the majority of our fellow humans in the West as well as in those parts of the world to which our Western civilization has been explored. And yet, clearly, to safeguard the future of humanity as a whole there is an urgent need for a creative response to the "stimulus" that is continuously presented by the ever-present origin. Otherwise the already exhausted mental-rational consciousness will simply collapse together with all its numerous projections--our Western civilization as a whole--and in the process possibly devastate this planet for centuries to come. As Gebser observes: "We are on trial."[27]