The universe, including humans, arose from exclusively natural processes without any supernatural or metaphysical involvement. The pursuit of life is self-determined. Morality, as well as meaning is only a product of human construction, either by the individual or the society. There is no afterlife to look forward to, only a final natural death. Atheism, existentialism, secular humanism, and nihilism would all fit into this category.
Transcendentalism claims that the universe is primarily spiritual.
According to this view, the natural world is an illusion or merely a manifestation of the spiritual-ness of all things. The pursuit of life is unity, and this goal is finally achieved through the process of reincarnation. After each death, one assumes another life form based upon their performance in this life, until finally one reaches the state of nirvana, the ultimate rejoining with the spiritual fabric of the universe. Many eastern religions, the New Age movement, scientology, wicca, and polytheism all fit into this category. Theism claims that both the physical and spiritual realms are distinct parts of reality.