 For Śaṅkara, the existence of the phenomenal empirical world alongside that of nondual brahman is in fact an illusory false reality. They are one, not two. Yet the world’s indeterminable appearance sets up a two-tiered (or two truths or two orders) approach to reality: (1) The conventional intersubjective empirical reality (vyāvahārikasattā) that comprises the universe; and (2) the ultimate reality (pāramārthikasattā) of nondual existence that is brahman. This hierarchy of two orders and their asymmetrical relationship avoids their mutual contradiction. A conscientious reader must understand this distinction and be mindful that Śaṅkara toggles his perspective between the two. This distinction is also foundational for comprehending his views on consciousness and his philosophical methods intended to culminate in mokṣa, more on which below.