the sixth circuit of Havona

  P.292 - §1 Ascenders of space are designated "spiritual graduates" when translated from the seventh to the sixth circle and are placed under the immediate supervision of the supremacy guides. These guides should not be confused with the Graduate Guides--belonging to the Higher Personalities of the Infinite Spirit--who, with their servital associates, minister on all circuits of Havona to both ascending and descending pilgrims. The supremacy guides function only on the sixth circle of the central universe.
 

Ascenders become fourth-stage spirits when they meet Supremacy Guides.

P.348 - §1 1. We know from the records that mortals are spirits of the first order during their sojourn in the minor sectors, and that they advance to the second order when translated to the major sectors, and to the third when they go forward to the central training worlds of the superuniverse. Mortals become quartan or graduate spirits after reaching the sixth circle of Havona and become spirits of the fifth order when they find the Universal Father. They subsequently attain the sixth stage of spirit existence upon taking the oath that musters them forever into the eternity assignment of the Corps of the Mortal Finality.
P.292 - §4 When the supremacy guides deem their pupils ripe for advancement, they bring them before the commission of seventy, a mixed group serving as examiners on the pilot world of circuit number six. After satisfying this commission as to their comprehension of the Supreme Being and of the Trinity of Supremacy, the pilgrims are certified for translation to the fifth circuit.