Quaternary2

Deity is spoken of as fourfold, the four-faced Brahma, the creative Logos which is a three-in-one with its emanated light as a fourth; or in another system, the ineffable, silence, father, and truth; or again in still another system the three flames and four wicks. Of the seven groups of angels or higher dhyani-chohans, the rupa-dhyanis form a quaternary; often in exoteric writings only four of seven are mentioned, the higher three being esoteric.
The two principal meanings of the quaternary are summed up in the tetraktys; it has four planes, and the fourth plane is in itself a four. The higher triad with the material world added as a pendant unit makes a quaternary; and this material world unfolded makes a new quaternary. There is a celestial or spiritual quaternary, just as there is a material and physical quaternary; and the element-principles of the universe may be so divided that an intermediate quaternary springs into view.