The ego-sense of the individual human being starts with an identification with the body and life-energy in the body. Observing and interacting with a child, we can see the strength of this identification in the way the child defines himself and responds to others as he grows. This identification is not, however, limited to the child but carries through into the adult life and gets reinforced by identification with specific vital forces, desires, loves, hates, relationships and, eventually, by mental disposition to accept that identification as one’s “self”. As long as we identify ourselves with the body-life-mind nexus, we are unable to understand the larger context of life or shift our standpoint to the divine standpoint. Sri Aurobindo observes: The Soul “…thinks of itself as the body, suffers with the body, enjoys with the body, is born with the body, is dissolved with the body; or so at least it views its self-existence.” If it begins to identify with the nexus of life-energy, “it thinks of itself as the life, craves with its cravings or desires, wallows in its pleasures, bleeds with its wounds, rushes or stumbles with its movements. If it is still mainly governed by the body-sense, it identifies its own existence with that of the whorl and thinks ‘When this whorl is dissipated by the dissolution of the body round which it has formed itself, then I shall be no more.’ If it has been able to sense the current of life which has formed the vortex, it thinks of itself as that current and says ‘I am this stream of life; I have entered upon the possession of this body, I shall leave it and enter upon the possession of other bodies: I am an immortal life revolving in a cycle of constant rebirths.”
In the Taittiriya Upanishad, Bhrigu, Varuna’s son, is guided through a series of realisations to determine “that from which these creatures are born, whereby being born they live and to which they go hence and enter again; for that is the Eternal.” Bhrigu begins, as all seekers begin, by identification with the physical body. Further concentration leads him to the identification with the life-force. Even this is not sufficient and he is asked to continue until he overcomes the illusory identification with the body-life-mind and achieves the divine standpoint.
Sri Aurobindo, The Synthesis of Yoga, Part Two: The Yoga of Integral Knowledge, Chapter 6, The Synthesis of the Disciplines of Knowledge, pp. 321-322