A collection of early Christian theological writings unfolds a systematic exposition of first principles: the nature of God, Christ, and the Spirit; the origin and destiny of rational souls; cosmology and the moral causes of good and evil; angels, free will, resurrection, judgment, and the possibility of universal restoration. It sets out allegorical methods for reading Scripture, responds to questions about the authority of certain texts in correspondence, and offers a reasoned apologetic reply to a pagan critic that marshals philosophical argument and extensive scriptural citation.