Beatus Vir, the first of six planned volumes translating Denis the Carthusian's (1402-1471) extensive Commentary on the Psalms (Psalms 1-25), is the first ever translation of this work into English since Denis wrote it in the 1430s. Of more than mere historical interest, this translation, accompanied by helpful footnotes, is intended to encourage an increased knowledge of the Psalms and to be used as an aid to meditation and reflection. Written at the cusp between late Scholasticism and the Devotio Moderna, the Commentary bridges both spiritual movements, seeking a firm foothold in both. Intensely Scriptural and personal, and urging perfection in the Christian manner of living or conversatio, the Commentary is also theologically rigorous, readily grasping the rational, guiding hand of St. Thomas Aquinas and happily embracing the mysticism of pseudo-Dionysius. Pope Eugene IV (1383-1447) is reputed to have said upon reading the Carthusian's works: "May Mother Church rejoice that she has such a son!" The English-speaking world might similarly rejoice that Denis's Commentary on the Psalms is at long last being translated into the English tongue.