Against Marcion

Tertullian's defense of the unity of the Old and New Testaments, the goodness of the Creator, and the personal-trinitarian God shapes the entire subsequent Catholic biblical and trinitarian tradition.

"There is one God, the Creator of all things, the Father of Jesus Christ; the Old Testament and the New Testament have one and the same author." (Against Marcion, I.2)

Tertullian is theologically realist: the God revealed in the Hebrew Bible and the God revealed in Jesus Christ are the same real God, not two figures, not symbols, but one being.

"What is true is one; what is divided into two contraries cannot both be true; therefore Marcion's two gods cannot both be God, and the unity of the testaments witnesses to the unity of God." (Against Marcion, I.4)

Tertullian's arguments against Marcion were rapidly translated into Greek and shaped the Eastern anti-Marcionite tradition that produced Irenaeus, Origen, and the orthodox patristic synthesis.

"The Word of God, who became flesh in Christ, is the same Word who spoke in the prophets and through whom the world was made." (Against Marcion, II.27)

The five books proceed by careful systematic argument — close exegesis of biblical texts, scrutiny of Marcion's claims, point-by-point refutation. Tertullian was trained as a lawyer and the work has the careful evidentiary structure of legal argument.

"I shall examine each of Marcion's claims as I would examine a legal claim: with the rules of evidence and the rules of inference, and the reader shall judge whether his case stands." (Against Marcion, I.1)

Despite his polemical sharpness, Tertullian's defense of biblical-historical reading against allegorical-evaporating tendencies is the early ancestor of modern liberal-theological commitment to historical-grammatical interpretation.

"What scripture says, it says; it is not for us to make it say what we prefer." (Against Marcion, IV.19)

Tertullian was suspicious of philosophy ("what has Athens to do with Jerusalem?") but his theological vocabulary necessarily drew on the Greek philosophical tradition, especially Stoic logic and Platonic metaphysics.

"Whatever the philosophers have rightly said belongs to Christians; whatever they have wrongly said is to be rejected." (Against Marcion, V, philosophical interludes)

Tertullian's sola scriptura — the appeal to the biblical text as decisive against heretical innovation — is a structural ancestor of the Protestant principle, even though Tertullian also affirms apostolic tradition.

"The scripture is the rule against which Marcion's claims must be measured; he cannot escape the scripture by appeal to a higher tradition, for the scripture is itself the tradition." (Against Marcion, IV.2)