Mind and body each have an Experience station where catalyst is turned into accumulated bias; the spirit's works the same way, but by moonlight rather than day.

The concept

The spiritual complex cycle is the tarot's third group of seven, cards fifteen through twenty-one (77.12). Where the mind's Matrix reaches and the body's Matrix moves without ceasing, the spirit's foundation resists that kind of description at all: Ra calls it the deepest darkness, with the Potentiator of the Spirit arriving only as a sudden, generative awakening (79.20). Ra confirms that positive and negative adepts share this same starting Matrix and Potentiator; what divides them is the Catalyst of the Spirit, the point at which each adept begins to pick and choose what it will look into further (80.15).

That choosing plays out on strange ground. Asked, a few exchanges earlier in the same session, why the Matrix of the Spirit carries the Devil's name, Ra observes that light's effect on the spirit's darkness is often far less apparent than the darkness itself, so the path an adept takes in working the Catalyst of the Spirit tends to become a confused one; only a few manage to grasp the light of the sun outright, and the majority remain groping in moonlight, a light capable of deceiving as readily as it uncovers what is hidden (80.10). That moonlight is exactly the material the Experience of the Spirit works with, and Ra names it, by far, the most decisive influence on which way an adept's polarity finally settles (80.15).

What the working itself looks like: even an adept's most miserable catalyst, seen from the spirit's vantage, can be discriminated within that shadow until it yields a light equal to brightest noon — the positive, service-to-others outcome. The service-to-self adept, meeting the identical shadow, instead settles into it, grasps what daylight offers, and turns back toward the dark (80.15). Same moonlight, same Catalyst behind it; the discrimination each adept brings to the shadow is what this station measures.

Working with the archetype

That relocates the fork later than intuition suggests. It is not the initial catalyst of the spirit that decides an adept's course — both polarities meet the same dark material — but the discrimination each applies to it afterward, before any noon-clear verdict is reached. Ra's general counsel for the archetypes holds here too: study the station first as its own concept complex, then in pairs, attending to the polarity each carries; actually clothing one's self within the card is advanced work for an adept long since established with the system, not the place to begin (89.19).

In Ra's words

The spirit's Matrix and Potentiator, characterized against the mind's and body's:

The Matrix of the Spirit is difficult to characterize since the nature of spirit is less motile. The energies and movements of the spirit are, by far, the most profound, yet, having more close association with time/space, do not have the characteristics of dynamic motion. Thusly one may see the Matrix as the deepest darkness and the Potentiator of Spirit as the most sudden awakening, illuminating, and generative influence.

79.20.8-10

Why the path through the spirit's catalyst so often reads as confused, even evil:

We do not wish to be facile in such a central query, but we may note that the nature of the spirit is so infinitely subtle that the fructifying influence of light upon the great darkness of the spirit is very often not as apparent as the darkness itself.

The progress chosen by many adepts becomes a confused path as each adept attempts to use the Catalyst of the Spirit. Few there are which are successful in grasping the light of the sun. By far, the majority of adepts remain groping in the moonlight and, as we have said, this light can deceive as well as uncover hidden mystery.

Therefore, the melody, shall we say, of this Matrix often seems to be of a negative and evil, as you would call it, nature.

80.10.2-6

The discrimination that turns shadow into noon — and the choice not to make it:

Even the most unhappy of experiences, shall we say, which seem to occur in the Catalyst of the adept, seen from the viewpoint of the spirit, may, with the discrimination possible in shadow, be worked with until light equaling the light of brightest noon descends upon the adept and positive or service-to-others illumination has occurred. The service-to-self adept will satisfy itself with the shadows and, grasping the light of day, will toss back the head in grim laughter, preferring the darkness.

80.15.8-9