Origen’s On First Principles is a foundational work in the development of Christian thought and doctrine: it is the first attempt in history at a systematic Christian theology. For over a decade it has been out of print with only expensive used copies available; now it is available at an affordable price and in a more accessible format. On First Principles is the most important surviving text written by third-century Church father, Origen. Origen wrote in a time when fundamental doctrines had not yet been fully articulated by the Church, and contributed to the very formation of Christianity. Readers see Origen grappling with the mysteries of salvation and brainstorming how they can be understood. This edition presents G. W. Butterworth’s trusted translation in a new, more readable format, retains the introduction by Henri de Lubac, and includes a new foreword by John C. Cavadini. As St. Gregory of Nazianzus, Doctor of the Church, wrote: “Origen is the stone on which all of us were sharpened.”