The Pleroma, or fullness , is a term from Gnosticism. It played a central role in the Valentinian system.
Hans Jonas states that “Pleroma is the standard term for the fully explicated manifold of divine characteristics, whose standard number is thirty, forming a hierarchy and together constituting the divine realm” (The Gnostic Religion:
The Message of the Alien God and the Beginnings of Christianity [London, Routledge, 1992 ] , p. 180 ).
In 1929, Jung said: “The Gnostics .. . expressed it as Pleroma, a state of fullness where the pairs of opposites, yea and nay, day and night, are together, then when they ‘become,’ it is either day or night. In the state of ‘promise’ before they become, they are nonexistent, there is neither white nor black, good nor bad”
(William McGuire, ed., Dream Analysis: Notes ef the Seminar Given in 1928- 1930 [Princeton: Princeton University Press/ Bollingen Series, 1984], p. 131).
In his later writings, Jung used the term to designate a state of preexistence and potentiality, identifying it with the Tibetan Bardo:
“He must … accustom himself to the idea that ‘time’ is a relative concept and needs to be compensated by the concept of a ‘simultaneous’ Bardo- or pleromatic existence of all historical processes. What exists in the Pleroma as an eternal ‘process’ appears in time as aperiodic sequence, that is to say, it is repeated many times in an irregular pattern”
(Answer to Job, GW II , § 629; see also pp. 620,624, 675,686, 727, 733 , 748).
The distinction that Jung draws between the Pleroma and the creation has some points of contact with Meister Eckhart’s differentiation between the Godhead and God.
Jung commented on this in Psychological Types (CW 6 , §§ 429ff.).
The relation of Jung’s Pleroma to Eckhart is discussed by Christine Maillard, Au coet1r du Livre Rouge. Les Sept Sermons aux Marts. Aux sources de la pense de C. G. Jung (Paris: la compagnie du livre rouge, 2017), pp. rr8 – 20. In 1955- 56,
Jung equated the Pleroma with the alchemist Gerhard us Dorn’s notion of the unus mundus (one world) (Mysterium Conit1nctionis, C\V 14, § 660 ).
Jung adopted this expression to designate the transcendental postulate of the unity underlying the multiplicity of the empirical world (ibid., pp. 759ff.) . ~The Black Books, Vol. V., Page 271, fn 388