Well, I suppose some readers may be mystified by this idea of an inner river.
We have, some of us, an occasional contact with a higher energy; yet we don't understand that this energy is everywhere, at all times, and that it ought to flow within us ceaselessly. That is, it does flow within us (and all things) ceaselessly, but we are completely unaware of it. Even the greatest esoteric teachings often don't explain to us that we need to come into relationship, an organic relationship, with this influence, this inward flow. The two teachers whose writings make this abundantly clear, in my experience, are Jeanne de Salzmann and Swedenborg, both of whom understood these influences, their Divine nature and implications, and the need to come under them.
This force is truly a river that flows, and the organic relationship with it informs, or inwardly forms, Being. In a certain way, it is impossible to make any sense at all out of outer life unless this river is sensed within. There is no understanding without its active presence.
Human beings on spiritual paths almost invariably think that it 's their own Being which will be inwardly formed through spiritual development—we're all like that, within our outwardly formed parts—whereas nothing of the kind is the case. If Being begins to form, it is its own Being, not that of the individual. The individual has a place and a role in this that can't be exactly described, but it is like coming directly into a loving relationship with God from an inward point of view. Under such conditions, Being becomes the force through which all manifestation arises and the center of gravity through which it locates itself. A responsible individual—one who responds—begins to sense this.
This is not a mental or psychological experience; all of the parts sense it. Thinking of it, as we do when we read about it, is relatively useless. It has to be lived.
Sometimes this river is described as Presence; but to me, that seems somehow inadequate. It is that it is. Every attempt to arrive at definitions ends up being a mistake. This is because the inner river is formed of a current of what Gurdjieff called particles of His Endlessness, that is, transcendental, material. It penetrates everything; all things are made of it. To participate in its action is to participate in the eternal and immediate act of creation. Nothing can be more interesting than this; everything orbits it.
While the superficial or external meaning of adultery is obvious, the mesoteric meaning of it— as Gurdjieff gave it to Ouspensky — is that schools and teachings should not be mixed.
The esoteric meaning of it, however, is an inward one: the currents of the two rivers cannot be mixed. This is a different and much more serious level of temptation, especially among those who have not been sufficiently touched by the difference between the two currents, and the sacred nature of the inward flow.
Gurdjieff made many allusions to the idea that it's man's birthright to be in relationship with the inner river, with an instinctive and organic sense of the sacred. In certain ways, the entire body of Beelzebub's Tales to His Grandson is about the loss of this property; and understanding that it is lost is the task that Jeanne de Salzmann gives us when she asks us to sense our lack.