2021 Reprint of the 1953 Edition. Facsimile of the original edition and not reproduced with Optical Recognition Software. Joseph de Guibert, S.J. (1877-1942) was one of the greatest spiritual theologians of the first part of the 20th century. Few spiritual writers during this period have written with equal theological depth, solidity, and balance. The Theology of the Spiritual Life is one the best English textbooks on spiritual theology available. The book is divided into seven parts. The first is an introduction to the study of spiritual theology in which the author defines and explains the terms "ascetical" and "mystical," distinguishes spiritual theology from the other branches of theology, especially moral and pastoral, explains the method and sources of spiritual theology, and adds some observations on its study. The second part treats of the nature of spiritual perfection, its relation to charity, habitual and actual, and to the other virtues and the counsels. He also discusses the relation existing between perfection and union with God, the imitation of Christ, suffering, active and passive conformity with the will of God, and the desire of perfection. The next part is a brief but solid treatise on the inspirations of the Holy Spirit, the docility required by the soul to profit by these inspirations, the gifts of the Holy Ghost and their relation to perfection, and the discernment of spirits. Man's cooperation with God is the main theme of Part IV, and after a chapter on the use of methods in spiritual life, the principal subject treated is that of spiritual direction, its nature and necessity, the qualities, duties, and role of a spiritual director. 1he following section is a treatise on mental prayer, its nature, degrees, necessity, and fruit, the states and habits of mind which can help or hinder mental prayer. In this section is treated the disputed question of acquired contemplation. The sixth part is concerned with the three degrees of the spiritual life, the qualities of soul in each degree, and the differences to be considered in regard to spiritual direction. This part closes with a chapter on the active and the contemplative life. The last section is on infused contemplation, its nature and degrees, its relation to spiritual perfection, and the extraordinary phenomena which sometimes accompany infused contemplation. Finally, there is added to the seven parts a brief bibliography of English books and a double index of names and subjects.