St. Symeon the New Theologian was abbot of the monastery of St Mamas in Constantinople at the turn of the eleventh century. He was also perhaps the most remarkable and certainly the most forceful advocate of the mystical experience of God in the history of the Byzantine Church. Though they were on occasion suppressed by ecclesiastical authorities wary of his fierce enthusiasm, as well as of his claims to charismatic authority, St Symeon's writings survived in the Orthodox Church and continued to play a vital role in the several renewals of spiritual life and prayer which has sustained the Church in its often difficult history over the past millennium. The treatises on the mystical life, usually rendered as The Ethical Discourses, comprise Symeon's most extensive treatment of the experience of God. They are also appearing here, in this and two following volumes, for the first time in English. Volume 1 selects those treatises devoted to the Church, the sacraments and the last things. St Symeon discusses salvation history from creation leading to the glory of the eschaton. He includes a special section on the cosmic dimension of salvation, the experience of the rapture in the "third heaven" by the apostle Paul, who saw, heard, tasted, smelled and felt the one Light which is God. Addressing such themes as predestination, the knowledge of the saints in the world to come, the day ofjudgment as the "day of the Lord," and the experience of the sacraments, St Symeon's theology is a summation of a lifelong study of the Scriptures and fathers, of an immersion in the liturgical life of the Church and of lived experience.