 Within Judaism there are a variety of movements, most of which emerged from Rabbinic Judaism, which holds that God revealed his laws and commandments to Moses on Mount Sinai in the form of both the Written and Oral Torah.Historically, all or part of this assertion was challenged by various groups such as the Sadducees and Hellenistic Judaism during the Second Temple period; the Karaites and Sabbateans during the early and later medieval period; and among segments of the modern non-Orthodox denominations.Modern branches of Judaism such as Humanistic Judaism may be nontheistic.