if he becomes the knowledge-soul, the Spirit poised in gnosis, vijñānamaya puruṣa, and puts on the nature of its infinite truth and power, if he lives in the knowledge-sheath, the causal body
Aurobindo identifies vijnanamaya purusa as the gnostic knowledge-soul whose realization is the indispensable condition for drawing the fullness of spiritual consciousness into terrestrial existence.
, The Synthesis of Yoga, 1948thesis