A philosophical doctrine concerning origination or causation, according to which the material effect is identical with, or pre-exists in, the material cause (e.g. the table as effect pre-exists in the wood). This position is held by the Sāṃkhya, the Yoga and the Vedānta schools (with the exception of Madhva's Dvaita Vedānta). Within the Vedānta school, Śaṅkara holds that the effect and its cause (the world and brahman (neut.) are actually identical, a doctrine sometimes referred to as satkāraṇavāda. The corollary of this is that any change is only apparent (the vivartavāda doctrine). For Rāmānuja, however, change is a real transformation (pariṇāma) of cause into effect (the pariṇāmavāda doctrine).