du·al·ism 
(də-lĭz′əm, dy-)
(də-lĭz′əm, dy-)n.
1. The condition of being double; duality.
2. Philosophy The view that the world consists of or is explicable as two fundamental entities, such as mind and matter.
3. Psychology The view that mental and physical properties are fundamentally different and that neither can be explained fully in terms of the other.
4. Theology
a. The concept that the world is ruled by the antagonistic forces of good and evil.
b. The concept that humans have two basic natures, the physical and the spiritual.
dual·ist n.
du′al·istic adj.
du′al·isti·cal·ly adv.