What is Substance Dualism?

Substance Dualism is the belief that the mind and body are two distinct substances. For instance, Descartes' Substance Dualism held that the mind was composed of a none-physical substance and that the body was composed of a physical substance. Substance Dualism can either claim that the mind and body, as two distinct substances, interact or do not interact. Some theories say both mental and physical events can impact each other (interactionism), some say physical events can impact mental events but not the other way around (epiphenomenalism), and some that neither interact with each other at all (parallelism). The key point to remember is that, unlike other forms of Dualism, such as Property Dualism, Substance Dualism holds that the mind and body are made of distinct substances.