The philosophical concept that the mind is completely independent of the body, and a contrast to Gross Materialism. Although there are several types of dualism, Cartesian Dualism exists only within the sphere of mind-body dualism.
Mind-body dualism assumes the existence of two distinct principles of being in the universe: spirit and matter, or soul and body. This was the basic understanding behind the teachings of Plato, according to which the physical world of sense phenomena is but a poor reflection or image of the true spiritual world; sense things being mere shadows of the eternal spiritual things or "Ideas". The goal of the philosopher was thus the elevation of consciousness, and the contemplation of these pure spiritual forms. Hence philosophy in its origin was a much more mystical or spiritual thing than it is today.
Mind-body dualism in the current philosophical understanding of the term originates from one man, the seventeenth century French philosopher Rene Descartes. It was Descartes who gave the world that much quoted utterance "I think, therefore I am". He was also the one who popularized the idea of reality as a dichotomy of matter (extended or spatial substance) and spirit (thinking substance, including God). This form of mind-body dualism became known as "Cartesian Dualism", after the Latin pronunciation of Descartes (Cartes).
Cartesian Dualism is made extremely difficult to accept if you consider the problem of interaction.