Anastasius of Sinai was a monk, priest, and abbot of the monastic community on Mount Sinai in the seventh century, remembered as a teacher and a defender of the Orthodox faith. By tradition he was tonsured and made a pilgrimage to Jerusalem to venerate the holy sites before settling on Mount Sinai, where he first served the ascetic community in a lowly capacity and in time became abbot of the whole brotherhood. The Orthodox Church commemorates him on April 20.
He lived during a period of intense Christological controversy, and his teaching and writing were directed against the errors of his age. He is remembered above all for his defense of the Chalcedonian confession of Christ as one person in two natures, divine and human, against the Monophysites, who held that Christ's humanity was subsumed into a single divine nature, and against the Monothelites, who professed a related error concerning Christ's human and divine wills. According to one account, his leadership and eloquence won him the title 'the New Moses.'
Several works are attributed to him. His principal treatise is the Viae Dux, known in Greek as the Hodegos or 'Guide,' a handbook of arguments in defense of Orthodox Christology. He also composed the Quaestiones et Responsiones, a collection of questions and answers offering pastoral and spiritual guidance to lay communities on matters such as marriage, charity, and daily life, and a Hexaemeron, a commentary on the six days of creation in Genesis. The tradition also credits him with sermons, including two on the creation of man according to the image of God, and with writing accounts of the lives of holy fathers.
