The term dualism is the state of being dual, or having a twofold division. Dualism doctrine consists of two basic opposing elements. Generally it consists of any system which is founded on a double principle.

The term dualism has several uses:

Theological usage ("Western"/"theistic")

Main Article: Theology

In theology, dualism can refer to ditheism: the belief that there are two basic principles in the universe, usually personified as deities, that work in polar opposition to each other. For example, one god is good, the other evil; or one god works for order, the other for chaos. Both the Zoroastrian religion, three millennia old and still extant, and the essentially dead gnostic religion (and its variations such as, Manichaeism, Bogomils, Catharism, etc.) are dualistic, as is Mandaeanism. The third-century Christian heretic Marcion of Sinope held that the Old and New Testaments were the work of two opposing gods. The Christian conflict between God (the source of all good) and Satan (the source of all evil) is sometimes described in dualistic terms.

Theological usage ("Eastern"/"mystic")

Main Article: Mysticism

Alternatively, dualism can mean the tendency of humans to perceive and understand the world as being divided into just two categories. In this sense, it is dualistic when one perceives a tree as a thing separate from everything surrounding it, or when one perceives a "self" that is distinct from the rest of the world. In traditions such as Zen, a key to enlightenment is "overcoming" this sort of dualism, without merely substituting it with monism or pluralism.

In orthodox Indian philosophy, on the other hand, monism is explicitly affirmed by advaita vedanta, while it is rejected in favor of the dualism or pluralism of Dvaita; other schools, such as Vishishtadvaita and bhedabheda try to find routes in between.

The Yin-Yang symbolizes the duality in nature and all things in Taoist philosophy.

The opposition and combination of the universe's two basic principles of Yin and Yang is a large part of Taoist philosophy. Some of the common associations with Yang and Yin, respectively, are: male and female, light and dark, active and passive, motion and stillness. Taoists believe that neither side is more important or better than the other; indeed, neither can exist without the other, as they are equal aspects of the whole. They are ultimately an artificial distinction based on our perceptions, so it is only our perception of them that really changes.

The complementary aspects of masculinity and femininity are revered by certain Neo-pagan religions.

Usage in philosophy of mind

Main Article: Mind dualism

In philosophy of mind, dualism is any of a narrow variety of views about the relationship between mind and matter, which are seen as totally different kinds of things. This type of dualism is sometimes referred to as "mind and body". This is in contrast to monism, which views mind and matter as being ultimately the same kind of thing. See also Cartesian dualism.

Usage in philosophy of science

Main Article: The problem of other minds

In philosophy of science, dualism often refers to the dichotomy between the "subject" (the observer) and the "object" (the observed). Some critics of Western science see this kind of dualism as a fatal flaw in science. In part, this has something to do with potentially complicated interactions between the subject and the object, of the sort discussed in the social construction literature.

External links

• Dictionary of the History of ideas: (http://etext.lib.virginia.edu/cgi-local/DHI/dhi.cgi?id=dv2-05) Dualism in Philosophy and Religion

• Parody of dualistic Christianity (http://www.geocities.com/dbusnipe/subjective_truth/bubbles.jpg)

Usage in physics

Main Article: Duality

In physics, dualism refers to media with properties that can be associated with the mechanics of two different phenomena. Because these two phenomena's mechanics are mutually exclusive, both are needed in order to describe the possible behaviors.