Explain the Vedic shift from a concern with maintenance of material reality to a concern with transcendence of material reality, as articulated by the Upanishads. How does the internalization process of yoga aid in the goal of this Upanishadic shift? Finally, the relational engagement of bhakti complicates this internal movement towards transcendence. Given this, how does Sankara reconcile devotional worship of God with the Upanishadic goal of Brahman?