While one bird eats the fruit of the true, the other one stays unattached, uninvolved and unmoved. This is the Akshara Purusha. Sri Aurobindo describes this aspect of the Self: “This Spirit is eternal, always the same, never changed or affected by manifestation, the one, the stable, a self-existence undivided and not even seemingly divided by the division of things and powers in Nature, inactive in her action, immobile in her motion. It is the Self of all and yet unmoved, indifferent, intangible, as if all these things which depend upon it were not-self, not its own results and powers and consequences, but a drama of action developed before the eye of an unmoved unparticipating spectator. For the mind that stages and shares in the drama is other than the Self which indifferently contains the actin. This spirit is timeless, though we see it in Time; it is unextended in Space, though we see it as if pervading space. We become aware of it in proportion as we draw back from out inward, or look behind the action and motion for something that is eternal and stable, or get away from time and its creation to the uncreated, away from phenomenon to being, from the personal to impersonality, from becoming to unalterable self-existence. This is the Akshara, the immutable in the mutable, the immobile in the mobile, the imperishable in things perishable. Or rather, since there is only an appearance of pervasion, it is the immutable, immobile and imperishable in which proceeds all the mobility of mutable and perishable things.”
The call of the ascetic, the abandonment of life, action and the fruits of desire, is validated by the overwhelming experience if once the Soul comes in contact with this Akshara Purusha. At once, the world of action is convicted of a lesser, unreal status in the face of that experience. This the foundation of the Truth of the anchorite seeking realisation and liberation in silent deep meditation. While we may recognize this as a partial and incomplete Truth that does not account for the world and its manifestation, we can at least appreciate that those who get a taste of this experience are responding to something real and palpable that is an aspect of the Truth and the Reality that we deny at our own peril.
Sri Aurobindo, Essays on the Gita, Second Series, Part II, Chapter 15, The Three Purushas, pp. 422-423