H.P. Blavatsky continued to develop the relations between the upper triad (1st, 2nd, and 3rd Logos) and the middle quaternary (7th, 6th, 5th, and 4th cosmical principles) of the Kosmos in the Third Stanza. The reason that "Mahat" is referred to as "Universal Intelligence limited by Manvantaric duration" is because, when the solar system dies in its final cycle in Cosmic Kama at the close of the Maha-Manvantara, this reflection of the central point's Universal Mind can no longer operate through the four lowest manifested fields of activity. This Universal Intelligence, as an emanational unfoldment of the Divine Thought into the central point as the 3rd Logos of the upper triad and transferred into Mahat as the mirroring 5th cosmical principle (a reflected 3rd Logos) of the middle quaternary, pulls away from the Cosmic Kama, Cosmic Jiva, Astral Light, and Sthula-Sarira, per G. de Purucker's diagram in Fountain-Source on page 437. H.P. Blavatsky explained in The Secret Doctrine Dialogues on page 594 that "all these incarnating egos" in the four lowest realms are simply "rays" of Mahat. With the commencement of the Maha-Pralaya, Mahat pulls in these rays, disappears, and is merged with Parabrahman. This process is described by H.P. Blavatsky in The Secret Doctrine 2:69 when "Avyaya" (a reference to a specific "corporeal part" of the Mundane Egg as an "organized body" per G. de Purucker's definition in his Encyclopedic Theosophical Glossary) or Vishnu, in The Secret Doctrine 1:370, takes on the identity of Rudra, the Destroyer (Mahat, in this case) and "enters into the Seven Rays of the Sun and drinks up all the waters of the Universe." The "seven solar Rays dilate to seven suns and set fire to the whole Cosmos." It is made clear in The Secret Doctrine 2:611 that the "Universe" refers to the Prakritis of a solar universe with H.P. Blavatsky's insight that the "seven rays of the Sun at the final Pralaya" expand into "Seven Suns and absorb the material of the whole Universe." That is, the solar system is destroyed by an influx of energy from the Equatorial Sun and the Polar Sun. As a result, it explodes. During the 311 trillion-year Maha-Pralaya, Mahat returns to its source in the same way that it came during the 311 trillion-year Maha-Manvantara (through Pradhana, then the "Logos" or Paramatman, and finally upwards to Parabrahman).
If this process is examined from the perspective of the human principles, it must be explained differently. Instead of using page 437 from G. de Purucker's Fountain-Source, one needs to review page 435 where the Divine Monad or Atman corresponds with the Solar Sun. In The Secret Doctrine Dialogues on page 372, H.P. Blavatsky, in speaking about the Maha-Pralaya, noted that "every atom of the seven principles--even the refulgence of Atman-Buddhi . . . must remain outside the portal of Nirvana." Since the Atman of the human principles corresponds to the Solar Sun in Cosmic Kama for the cosmical principles, it is only natural that it too will be dropped away at the close of the Great Age. In both cases, we are viewing the close of the Great Age in terms of a solar system, per H.P. Blavatsky's recommendation in The Secret Doctrine 2:700.
H.P. Blavatsky, The Secret Doctrine (Pasadena: Theosophical University Press, 2019).
H.P. Blavatsky, The Secret Doctrine Dialogues ( Los Angeles: The Theosophy Company, 2014).
G. de Purucker, Encyclopedic Theosophical Glossary. Retrieved at theosociety.org.
G. de Purucker, Fountain-Source of Occultism (Pasadena: Theosophical University Press, 1974).
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