LaVeyan Satanism is an atheist religion founded in 1966 by American occultist and author Anton LaVey. Scholars of religion have classified it as a new religious movement and a form of Western esotericism.
LaVey established his movement in the U.S. state of California through the founding of his Church of Satan on Walpurgisnacht of 1966, which he proclaimed to be "the Year One", Anno Satanas—the first year of the "Age of Satan". His ideas were heavily influenced by the ideas and writings of Friedrich Nietzsche, Ayn Rand and Arthur Desmond. The church grew under LaVey's leadership, with regional grottos being founded across the United States. A number of these seceded from the church to form independent Satanic organizations during the early 1970s. In 1975, LaVey abolished the grotto system, after which LaVeyan Satanism became a far less organized movement, although it remained greatly influenced by LaVey's writings. In the coming years, members of the church left it to establish their own organizations, also following LaVey's ideas, among them John Dewey Allee's First Church of Satan and Karla LaVey's First Satanic Church.
The religion's doctrines, codified in LaVey's book, The Satanic Bible, are based on materialism, rejecting the existence of supernatural beings, body-soul dualism, and life after death. Adherents do not believe that Satan literally exists and do not worship him. Instead, Satan is viewed as a positive archetype representing pride, carnality, and enlightenment. He is also embraced as a symbol of defiance against Abrahamic religions, which adherents criticize for suppressing humanity's natural instincts and encouraging irrationality. The religion propagates a naturalistic worldview, seeing mankind as animals existing in an amoral universe. It promotes a philosophy based on individualism and egoism, coupled with Social Darwinism and anti-egalitarianism.
LaVeyan Satanism involves the practice of magic, which encompasses two distinct forms; greater and lesser magic.