 Everything in the universe undergoes constant change; however, according to Śaṅkara, objects cannot simply come into being and go out of being. They must depend on something else, some existent cause, for their being. Śaṅkara argues that prior to universe emergence, when all objects, time, and space, are unmanifest, only primordial undifferentiated existence exists (see ChUBh 6.2.1–2 for example). This existence is a single potential cause free of form; but even after the universe emerges, there is still just that single cause. It persists through all objects and causation, like the clay persists through its changing forms. He concludes that every object, including the universe itself, is a temporal artifact, simply a name (nāma) and form (rūpa). The entire universe is not different from brahman, and its form is less real than brahman. All forms are less real than existence itself. Foundational existence is transitive, lending existence to objects, like the clay to each of its forms. Furthermore, the relationship is asymmetrical—pure undifferentiated existence does not depend on objects, but objects depend on existence. Objects borrow their existence from this metaphysical ground and lack any independent being apart from it. They are not different than their cause, and therefore their names and forms are only provisionally real appearances.