This book is an in-depth examination of the pneumatology of Origen of Alexandria. Justin J. Lee argues that Origen conceives of the Holy Spirit as a divine person, but inferior in nature in both person and work. This can be discerned from his understanding of the Son and Father, as well as the influence of Middle Platonism on his theological and cosmological framework. Ontologically, Origen's understanding of Trinity is a hierarchy of divine persons in which the greater ministers to the existence of the lower. Origen's pneumatology can be best understood by examining how he speaks about the work of the Holy Spirit. The Spirit participates in the divine work of salvation, reflecting an economic Trinity of shared work and will. The Spirit's primary role is to indwell and assist the saints. There are two major actions of the Holy Spirit's work: (1) the downward action of God, where the Spirit is the distributor of the divine gifts and graces and (2) the Spirit's upward work of revelation and sanctification, by which he leads the saints to the Son and Father. The Spirit thus serves as the practical and personal initiator of believers into the greater processes of salvation and deification.