Dualism (noun)

1. The state of being dual; the condition of having two parts.
2. The belief that there are two independent principles in the universe: mind and matter, good and evil, God and the devil, etc.
3. The belief in the existence of two distinct kinds of being or reality.

Origin:

Late 17th century: from french dualisme, or via late latin from greek dualismos, from dualis (from duo "tw.o")

Examples:

1. The philosopher argued that the mind and body were two distinct entities, an example of dualism.
2. In the dualism of good and evil, the devil is the embodiment of evil.
3. The dualism of the capitalist economic system, private ownership and state control.
4. The dualism of the nature and culture, the human and non-human.
5. The dualism of the traditional and modern, the Eastern and Western culture.