Dichotomy is the belief that man consists of two parts, the body and the soul.  This may also be viewed as man's physical being and his non-physical being.

Some ancient philosophies held that the body was evil while the soul was good.  Therefore man's nature is a battle between good and evil, the physical and the spiritual. 

An alternative view to dichotomy is that man is a trichotomy consisting of three parts.  This separates the soul into soul and spirit.