St. Maximus the Confessor (c. 580-662)

Monk and theologian who defended the two wills of Christ (dyothelitism) against Monothelitism at the cost of his tongue and right hand being cut off. His Christological, cosmological, and ascetical synthesis is among the most profound in Orthodox theology. Also wrote the Mystagogia (mystical commentary on the Liturgy). Feast: January 21.