A treatise On the Trinity, once ascribed to Priscillian of Avila, but now more commonly held to be the work of a disciple, quotes the aphorism "the name of the Father is the Son" as an apostolic saying. In fact it appears to be a quotation of the Gospel of Truth, affinities to which are also visible in the teaching of this treatise on the procession of the Word from the Father, the role of the Holy Spirit in this procession, the universal bondage of the human race in oblivion, the revelation of the Father's face to the elect, and the common brotherhood of the elect with Christ. After noting a further affinity between the Gospel of Truth and another Priscillianist writing, the article concludes with some reflections on the use of apocryphal literature in the fourth century by authors whose theology was in most respects orthodox. A treatise On the Trinity, once ascribed to Priscillian of Avila, but now more commonly held to be the work of a disciple, quotes the aphorism "the name of the Father is the Son" as an apostolic saying. In fact it appears to be a quotation of the Gospel of Truth, affinities to which are also visible in the teaching of this treatise on the procession of the Word from the Father, the role of the Holy Spirit in this procession, the universal bondage of the human race in oblivion, the revelation of the Father's face to the elect, and the common brotherhood of the elect with Christ. After noting a further affinity between the Gospel of Truth and another Priscillianist writing, the article concludes with some reflections on the use of apocryphal literature in the fourth century by authors whose theology was in most respects orthodox.