Three treatises by twelfth-century Cistercians, who reflect on the human person as the image of God and capax Dei, capable of God, of being reformed to the divine Image. Of the three-Isaac of Stella, an anonymous Cistercian, and William of Saint Thierry- only the last discusses the nature ('the physics') of the body as well as of the soul, giving us an insight into medieval medical theory as well as to theological anthrology.