I've written on a number of occasions about the role of centers in inner work, and the fact that Gurdjieff's enneagram is- among other things- a diagram of inner energy centers, or chakras.
This point seems lost on a lot of people I talk to. I have even had the reaction, from very intelligent and serious people, long term "aspiring disciples of Gurdjieff," so to say, of:
Various schools of yoga, and other schools interested in the flow of "esoteric" energy (AKA chi, prana, etc.) within the body, have proposed a wide variety of systems to explain how, when, where and why energy flows in this, that, or the other direction. Proposals include energy flowing up, down, in circles, front, back, and so on.
The body is an extremely complex system. In the absence of a comprehensive interpretive tool to understand it, so many different things go on that it's well nigh impossible to bring order to it. The temptation is to make up the best analogue you can.
Gurdjieff's diagram removes the subjectivity from this question. This diagram is a picture of how the inner centers of the human body are set up, what the relationships between them are, and how energy flows between them. In other words, this is a picture of your inner machine.
The psychological interpretations of this diagram pale in significance to this physical understanding, because if one works to comprehend this system through inner exercise, one obtains a key to gently unlock the secrets of the system in a balanced manner.
The dynamic nature of the diagram, and its intricacy, go a long way towards explaining why there are so many systems claiming to explain how energy moves. Each one of them understands part of the picture, but few, if any, of them really see how the whole system is in relationship. Furthermore, none of the other systems understand the role of the law of three- a higher energy- in producing shocks to raise the rate of vibration at the critical junctions (3 and 6.)
I have taken the liberty in the diagram above of providing a specific set of relationships between body centers, or chakras, and the various notes in the enneagram.
It's essential to obtain a direct and practical understanding of this diagram and its action within the body if you want to understand your machine. Nothing we wish to achieve can take place outside the context of this inner structure.
There are a great number of valuable inner exercises that can be undertaken using this diagram. Many of them will help to explain piecemeal understandings from other systems. Relationships involving upper and lower triads, as well as the exchange of energy between them and their dynamic interation with each other, are all subject to the laws of the ennegream and can be discerned and put in a reliable context with a discriminating use of the system.
The most remarkable thing about this diagram, for me, is that it deftly knits the teachings of many other systems together.
Remember: in Gurdjieff's system, the functions of the universe are determined by the law of three and the law of seven, which interact directly in the enneagram to produce completed octaves. Unless we want to subvert and throw out the whole of Gurdjieff's teaching, we must presume things can't happen inside us any other way. Even if they happen wrongly, or don't happen at all, they do so in the context of these laws.
Using this valuable tool to study our inner condition is well worth the time. If the energy in the body is brought even one step forward into right relationship, many other things which seem quite impossible now will gradually take place of their own accord.