Second- and third-century broader category of Trinitarian heresies that protected the substantive unity (Greek monarchia, single principle, single rule) of God by reducing the three to one. The heretical concern was substantively orthodox: God is one. The heretical solution was to collapse the substantive distinction between the three Persons. Two principal forms developed. (1) Modalist monarchianism: Father, Son, Spirit are three successive modes or manifestations of the one God. Principal teachers: Noetus of Smyrna (late second century); Praxeas (early third century, refuted by Tertullian's Against Praxeas); Sabellius (third century, the most famous; gives the alternative name Sabellianism); the later Patripassian form (the Father suffered as the Son on the cross). (2) Dynamic monarchianism (also called adoptionist monarchianism): Christ is a mere man on whom the divine power (dynamis) descended at His baptism or in a similar way; Christ is not himself the eternal Son of God but is divinely empowered. Principal teachers: Theodotus of Byzantium (late second century at Rome); Paul of Samosata (mid-third-century bishop of Antioch, condemned by the Synod of Antioch 268-269). The orthodox Trinitarian confession safeguards both the unity of God (one substance, one being) and the distinction of the three Persons (eternal, substantial, ungeneratable). The Reformed-confessional tradition (Westminster Confession II.3; Athanasian Creed; the Nicene-Constantinopolitan Creed) maintains the orthodox confession against both Modalist and Dynamic Monarchianism.