Mormonism is unusual among contemporary forms of Christianity in that it expounds a pluralist viewpoint. According to its founder, Joseph Smith, a multiplicity of inhabited worlds is part of God's plan of salvation. This truth supposedly came to Smith in a series of revelations and is said to be evinced by various Old Testament passages (for example, Moses 1: 33, 35). The Mormon acceptance of the existence of other worlds created by God for a divine purpose has less in common with contemporary scientific extraterrestrial speculation than it does with theological arguments for pluralism put forward before the 20th century.