Causation was acknowledged as one of the central problems in Indian philosophy. The classical Indian philosophers’ concern with the problem basically arose from two sources: first, the cosmogonic speculations of the Vedas and the Upaniṣads, with their search for some simple unitary cause for the origin of this complex universe; and second, the Vedic concern with ritual action (karman) and the causal mechanisms by which such actions bring about their unseen, but purportedly cosmic, effects. Once the goal of liberation (mokṣa) came to be accepted as the highest value, these two strands of thought entwined to generate intense interest in the notion of causation. The systematic philosophers of the classical and medieval periods criticized and defended competing theories of causation. These theories were motivated partly by a desire to guarantee the efficacy of action and hence the possibility of attaining liberation, partly by a desire to understand the nature of the world and hence how to negotiate our way in it so as to attain liberation.
Indian philosophers extensively discussed a number of issues relating to causation, including the nature of the causal relation, the definitions of cause and effect, and classifications of kinds of causes. Typically they stressed the importance of the material cause, rather than (as in Western philosophy) the efficient cause. In India only the Cārvāka materialists denied causation or took it to be subjective. This is unsurprising given that a concern with demonstrating the possibility of liberation motivated the theories of causation, for only the Cārvākas denied this possibility. The orthodox Hindu philosophers and the heterodox Buddhists and Jainas all accepted both the possibility of liberation and the reality of causation, though they differed sharply (and polemically) about the details.
The Indian theories of causation are traditionally classified by reference to the question of whether the effect is a mode of the cause. According to this taxonomy there are two principal theories of causation. One is the identity theory (satkāryavāda), which holds that the effect is identical with the cause, a manifestation of what is potential in the cause. This is the Sāṅkhya-Yoga view, though that school’s particular version of it is sometimes called transformation theory (pariṇāmavāda). Advaita Vedānta holds an appearance theory (vivartavāda), which is often considered a variant of the identity theory. According to the appearance theory effects are mere appearances of the underlying reality, Brahman. Since only Brahman truly exists, this theory is also sometimes called satkāraṇavāda (the theory that the cause is real but the effect is not).
The other principal theory of causation is the nonidentity theory (asatkāryavāda), which denies that the effect pre-exists in its cause and claims instead that the effect is an altogether new entity. Both adherents of Nyāya-Vaiśeṣika and the Buddhists are usually classified as nonidentity theorists, but they differ on many important details. One of these is whether the cause continues to exist after the appearance of the effect: Nyāya-Vaiśeṣika claims it does, the Buddhists mostly claim it does not.
Finally, some philosophers try to take the middle ground and claim that an effect is both identical and nonidentical with its cause. This is the position of the Jainas and of some theistic schools of Vedānta.
The Truth about Śrīgupta’s Two Truths: Longchen Rabjampa’s “Lower Svātantrikas” and the Making of a New Philosophical School