This is a remarkable product of Byzantium's last great flowering of theology. For the author, man's redemption in Jesus Christ is not just a matter of history. It is a saving event in which man is called to participate here and now, in body and spirit as well as intellect, through the sacramental life of the Church. The vitality of worship, and not just its form, therefore is the focus of Cabasilas' thought. The work has long been essential reading for specialists in the fields of comparative liturgy and history of liturgy, since Cabasilas comments in detail on the Byzantine rite of his day and is able to draw comparisons with the Roman liturgy as well. The work is also invaluable for all those who wish to understand more about the theory and practice of worship in the Orthodox Church. In this edition the text of the Commentary, translated by J. M. Hussey and P. A. McNulty, has been supplemented by a brief foreword which places Cabasilas' work in its historical context. A helpful introduction by R.M. French describes the celebration of the liturgy in the Orthodox Church.