Neopaganism, polytheistic religious movement, practiced in small groups by partisans of pre-Christian religious traditions such as Egyptian, Greek, Norse, and Celtic. Neopagans fall into two broad categories, nature-oriented and magical groups, and often incorporate arcane and elaborate rituals. Two of the movement’s most influential thinkers were Alphonse L. Constant (1810 – 75) and Gerard Encausse (1865 – 1916).