Dualism is a philosophical concept that posits the existence of two fundamental and distinct realities or substances. In the context of mind and body, it suggests that the mind is non-physical and separate from the physical body. This idea is often associated with the work of René Descartes, who argued that mental phenomena cannot be fully explained by physical processes alone. In addition to mind-body dualism, there are other forms of dualism, such as moral dualism, which contrasts good and evil as opposing forces. Dualism has influenced various fields, including psychology, religion, and metaphysics, prompting discussions about the nature of existence and consciousness.