Scholars have long wondered about the source of Mormon doctrines, many of which differed significantly from the Protestantism that dominated Joseph Smith's environment. In 1994 John Brooke's Refiner's Fire proposed that Joseph Smith drew on Renaissance "hermeticism", esoteric beliefs influenced by the antique Corpus Hermericum. Mormon scholars criticized Brooke, often arguing for ancient connections inaccessible to Smith, while scholars of Western esotericism argued that the concept of hermeticism was problematic and that the esoteric ideas labeled hermetic were actually Platonic. This dissertation argues that Smith's quest to restore what he called "the fulness of the gospel", or the complete truth that was missing from contemporary churches and even the Bible itself drew from the thought of Christians influenced by Plato and is best understood as a form of Christian Platonism. Thus, for Smith, "the fulness of the gospel" included the restoration of divination, the central Christian-Platonic doctrine, as well as the rites and priesthood offices needed to achieve it.

Though Smith would not have designated himself a Christian Platonist (most Christian Platonists would not have either), he gravitated towards such ideas, which were available to him through a variety of routes, including popular forms of religiosity embraced by his family; the views of key followers; and the scholarship of his day as summarized in histories, encyclopedias, and other reference works. Viewing Joseph Smith's folk practices, utopianism, temple rituals, soteriology, marital practices, and political ambition through a Christian-Platonic lens allows us to see underlying connections that make intelligible many disparate and peculiar aspects of early Mormonism.