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.
Philosophy of religion
World Religions put forth various theories which affirm life after death and different kinds of postmortem existence. This is often tied to belief in an immortal individual soul or self (Sanskrit: atman) separate from the body which survives death, as defended by Plato, Descartes, Monotheistic religions like Christianity and many Indian philosophers. This view is also a position on the mind body problem, mainly, dualism. This view then must show not only that dualism is true and that souls exist, but also that souls survive death. As Kant famously argued, the mere existence of a soul does not prove its immortality, for one could conceive that a soul, even if it is totally simple, could still fade away or lose its intensity. H.H. Price is one modern philosopher who has speculated at length about what it would be like to be a disembodied soul after death.