Dualistic cosmology
Moral dualism is the belief of the great complement of, or conflict between, the benevolent and the malevolent. It simply implies that there are two moral opposites at work, independent of any interpretation of what might be "moral" and independent of how these may be represented. Moral opposites might, for example, exist in a worldview which has one god, more than one god, or none. By contrast, duotheism, bitheism or ditheism implies (at least) two gods. While bitheism implies harmony, ditheism implies rivalry and opposition, such as between good and evil, or light and dark, or summer and winter. For example, a ditheistic system could be one in which one god is a creator, and the other a destroyer. In theology, dualism can also refer to the relationship between the deity and creation or the deity and the universe (see theistic dualism). This form of dualism is a belief shared in certain traditions of Christianity and Hinduism. Alternatively, in ontological dualism, the world is divided into two overarching categories. The opposition and combination of the universe's two basic principles of yin and yang is a large part of Chinese philosophy, and is an important feature of Taoism. It is also discussed in Confucianism.
Dualistic cosmology
For example, Mazdaism (Mazdean Zoroastrianism) is both dualistic and monotheistic (but not monist by definition) since in that philosophy God—the Creator—is purely good, and the antithesis—which is also uncreated–is an absolute one. Zurvanism (Zurvanite Zoroastrianism), Manichaeism, and Mandaeism are representative of dualistic "and" monist philosophies since each has a supreme and transcendental First Principle from which the two equal-but-opposite entities then emanate. This is also true for the lesser-known Christian gnostic religions, such as Bogomils, Catharism, and so on. More complex forms of monist dualism also exist, for instance in Hermeticism, where "Nous" "thought"—that is described to have created man—brings forth both good and evil, dependent on interpretation, whether it receives prompting from the God or from the Demon. Duality with pluralism is considered a logical fallacy.