From Pope Gregory the Great in the fifth century to the death of Richard of St. Victor in 1173, the author of The Anti-Christ (p. 1339) continues his highly acclaimed history of Western mystics and their world. For McGinn (Divinity/Univ. of Chicago) mysticism is ``primarily (but not solely) an ecclesial tradition of prayer and practice nourished by scripture and liturgy in order to foster awareness of whatever direct forms of divine presence may be available in this life.'' True to this holistic vision, he offers us a diet rich in quotations from the mystics themselves in analysis of their concepts and in discussion of recent studies. He gives context in his introduction, which offers a concise account of how the western Roman Empire evolved into Christendom. Then we encounter the massive intellect of the ninth-century Irishman John Scottus Eriugena, who spanned Celtic, Latin, and Greek cultures and made available for Charlemagne's West the writings of such eastern Christians as Dionysius, Gregory of Nyssa, and Maximos Confessor. McGinn guides us through Eriugena's immense vision of Nature as dialectically proceeding from, and returning to, God. He provides a masterly treatment of Pope Gregory's understanding of the roles of contemplative and active life as applied to Christianity, going on to cover the genius and influence of St. Benedict. The high point of this volume is McGinn's study of Bernard of Clairvaux, which illuminates Bernard's doctrine of the image of God in the human person and his teachings on experience, the spiritual (or inner) senses, and the essentially spousal love between Christ and the soul. The author also explicates the writings of the early Carthusians and St. Aelred's mystical concept of friendship. He concludes with a survey of French Victorine authors with ``scholastic'' propensities. McGinn's clear and beautiful style aptly expresses his serene command of this highly varied material.