Dualism (Indian philosophy)
Dualism in Indian philosophy refers to the belief held by certain schools of Indian philosophy that reality is fundamentally composed of two parts. This mainly takes the form of either mind-matter dualism in Buddhist philosophy or consciousness-matter dualism in the Samkhya and Yoga schools of Hindu philosophy. These can be contrasted with mind-body dualism in Western philosophy of mind, but also have similarities with it.
Trialism
Cottingham introduced trialism after citing that Descartes' account of sensation and imagination has opened his official dualism under considerable pressure. He cited that an evaluation of the Cartesian writings on human psychology there is a grouping of not two but three notions - mind, body, sensation, hence the term trialism. According to cottingham, Descartes added the third category or notion " alongside thought and extension without proceeding to reify it as a separate substance." Thinkers such as Daniel Garber and Tad Schmaltz supported this by citing a letter in the correspondence between Descartes and Princess Elizabeth of Bohemia, which indicated that that he changed his mind from a dualistic view.