That S. Thomas is to be accepted as a master of mysticism may be judged from the following facts in the life of a mystic of the mystics, S. John of the Cross: "It has been recorded that during his studies he particularly relished psychology; this is amply borne out by his writings. S. John was not what one could term a scholar. He was, however, intimately acquainted with the _Summa_ of S. Thomas Aquinas, as almost every page of his works proves.... He does not seem to have ever applied himself to the study of the Fathers.... As has already been stated, the whole work (_The Ascent of Mount Carmel_) is based upon the view S. Thomas Aquinas takes of the essence and operations of the senses and of the faculties of the soul, and upon his treatise on the virtues."[1] S. Thomas hardly needs an imprimatur after six centuries of full trust. But in the hard matters of mysticism, which he has treated as a scholar should, it is reassuring to know that he has the approval, not only of the scholars, but of the mystics. VINCENT McNABB, O.P. CONTENTS INTRODUCTION QUESTION LXXXI OF THE VIRTUE OF RELIGION QUESTION LXXXII OF DEVOTION QUESTION LXXXIII OF PRAYER SUPPLEMENT--QUESTION LXXII OF THE PRAYERS OF THE SAINTS WHO ARE IN HEAVEN QUESTION CLXXIX OF THE DIVISION OF LIFE INTO THE ACTIVE AND THE CONTEMPLATIVE QUESTION CLXXX OF THE CONTEMPLATIVE LIFE QUESTION CLXXXI OF THE ACTIVE LIFE QUESTION CLXXXII OF THE COMPARISON BETWEEN THE ACTIVE AND THE CONTEMPLATIVE LIFE QUESTION CLXXXVI ON THE RELIGIOUS STATE INDEX INDEX OF TEXTS QUOTED OR EXPLAINED INTRODUCTION The pages which follow call for little introduction. S. Thomas has left us no formal treatise on Mystical Theology, though his teachings on this subject have been collected from his various works and combined to form such a treatise. Especially noteworthy is the work of the Spanish Dominican Valgornera.[2] No such synthesis has been attempted here. We have simply taken from the _Summa Theologica_ the treatises on _Religion_, on _Devotion_, _Prayer_, and the _Contemplative Life_, and presented them in an English dress. When occasion offered we have added to each portion appropriate passages from S. Augustine, S. Thomas's master, and more rarely from the _Commentary_ on the _Summa_ by the illustrious Cardinal Cajetan.