That which reincarnates, then, is the eternal individuality—the rational higher self—and not the mortal personality. Just as our mortal personality (our physical body and its etheric, astral, and desire attachments) is subject to the duality of wakefulness and sleep—where it exercises activity in wakefulness and retires for rest in sleep to digest the experience of its previous day, then prepares for a new awakening.

Likewise, our eternal individuality—our spirit and its illuminative and higher mental attachments—is subject to the duality of life and death, where it practices actions in life and retires for rest in death to digest the experience of its previous life, then prepares for a new birth.