The Fourth Way enneagram is a figure published in 1949 in In Search of the Miraculous by P.D. Ouspensky, and an integral part of the Fourth Way esoteric system associated with George Gurdjieff. The term "enneagram" derives from two Greek words, ennea (nine) and gramma (something written or drawn).
Enneagram with point numbers and octave designations for octave beginning at point 9. Points 3 and 6 show "shock points" at which a new Do may enter and develop alongside the existing octave.
The enneagram is a nine-pointed figure usually inscribed within a circle. Within the circle is a triangle connecting points 9, 3 and 6. The inscribed figure resembling a web connects the other six points in a cyclic figure 1-4-2-8-5-7. This number is derived from or corresponds to the recurring decimal .142857= 1/7. These six points together with the point numbered 9 are said to represent the main stages of any complete process, and can be related to the notes of a musical octave, 9 being equivalent to "Do" and 1 to "Re" etc. The points numbered 3 and 6 are said to represent "shock points" which affect the way a process develops. The internal lines between the points; that is, the three-point figure and the six-point figure, are said to show certain non-obvious connections, although here very little elucidation is offered.
GI Gurdjieff Lecture About The Enneagram (from In Search Of The Miraculous)