All schools of Vedanta subscribe to the theory of Satkāryavāda, which means that the effect is pre-existent in the cause. But there are two different views on the status of the "effect", that is, the world. Most schools of Vedanta, as well as Samkhya, support Parinamavada, the idea that the world is a real transformation (parinama) of Brahman. According to Nicholson (2010, p. 27), "the Brahma Sutras espouse the realist Parinamavada position, which appears to have been the view most common among early Vedantins". In contrast to Badarayana, Adi Shankara and Advaita Vedantists hold a different view, Vivartavada, which says that the effect, the world, is merely an unreal (vivarta) transformation of its cause, Brahman.