Gregory of Nyssa is the most important author of the fourth century in relation to theological anthropology, and was one of the most outspoken of the early Church Fathers on the subject of slavery. Gregory’s theology is built upon his perception that Jesus Christ was truly human; therefore, to be human is to be made in the image of Christ. We cannot justify slavery if we accept that humans are made in God’s image, because slaves are no less made in the image of God than those who are free. This book examines Gregory’s theology, how he understood and taught about the relationship of human beings to God, and how he applied this theology to the practical issue of slavery.