Acharya Prashant explains that the Upanishads describe the ultimate state of liberation as one where the fragmented parts of the mind return to wholeness. He clarifies that the specific number of parts mentioned in scriptures, such as fifteen, is not significant; rather, it represents the 'manyness' or diversity of sensory experience. In the view of Vedanta, all diversity boils down to the 'mother ego tendency,' which is the subject that perceives all objects. He emphasizes that nothing exists independently of the perceiver, and to believe otherwise leads to suffering. The ego projects diversity to ensure its own survival and to allow time and change to exist, as experience requires duality and contrast.