“Ecce posui ante vos benedictionem et maledictionem” (Tert., Adv. Marc. IV.15.5); “Nos autem etiam ex his quæ adhuc apud eos custodiuntur, arguemus eos… in altera conscriptione” (Iren., Adv. haer. III.12.12: program of refutation “from what they still retain”).
Method. IV.15 proceeds exactly as the Irenaean program statement implies: the adversary is forced to yield doctrinal consequences “from within” the very materials he claims. Tertullian does not attempt to win by importing alien authorities into Marcion’s system; he instead treats Marcion’s moral “signature” (a god who is only benign and never judicial) as testable against the dominical logoi present in the retained Gospel. The pivot is the internal inconsistency of a Christ who begins with beatitudes yet must also pronounce vae: if the Vae is genuinely Christ’s utterance, then the Christ of Marcion necessarily knows indignation, admonition, commination, and vindication (“nemo… comminabitur… nisi qui factum vindicabit”), collapsing the Marcionite dichotomy of “good without judgment.” If, alternatively, the Vae is assigned to the Creator to preserve Marcionite “goodness,” the Creator is thereby confirmed as the proper moral evaluator of wealth and human praise—and the beatitudes already shown to cohere with the Creator’s concern for the humble. The logic is Irenaean in the strict sense: heresy is convicted by the residues of catholic Scripture it cannot eliminate, just as III.12.12 forecasts.
Structure. The chapter’s argumentative sequence is also recognizably “Irenaean” in macro-form: (i) establish that the Christ-voice in the Gospel cannot be split between two gods without contradiction; (ii) show that the same divine subject must be both beneficent and judicial; (iii) anchor this unity by appeal to the Creator’s prior scriptural pattern of paired destinies (blessing/curse; consolation/threat), so that the Gospel’s alternation of beatitudes and woes is not novelty but the same economy disclosed “then” and “now.” Irenaeus repeatedly insists—against Marcion’s reduction—that the one God is simultaneously good and just and that judgment is not foreign to goodness but belongs to the same Father who saves; in Book IV, this is pressed precisely by pairing evangelical sayings with the prophetic and Mosaic pattern and by refusing the premise that justice implies a different deity.
Historical polemic. Tertullian’s handling of Marcion as an “aftercomer” who must explain away the public, scriptural, and ecclesial shape of Christian proclamation matches the Irenaean profile of Marcion as one who dismembers the received Scriptures and then asserts the mutilated remainder as uniquely legitimate—especially Luke and Paul. That description in III.12.12 is not merely biographical; it supplies the polemical warrant for the procedure Tertullian is executing in IV: he can treat Marcion’s Gospel as evidence against Marcion, because (per Irenaeus) it is precisely the retained corpus that will convict him.
Inherited exegetical scaffolding. IV.15 reads less like free-standing Tertullianic invective than like a pre-shaped catena of dominical-logia contrasts designed for anti-Marcionite exploitation: beatitudes versus woes; poverty/hunger/weeping versus wealth/satiety/laughter; human blessing versus prophetic truth; prophets versus pseudoprophets. The chapter’s repeated “either/or” forcing moves (either Christ truly says vae and thus judges, or else the Creator owns the vae and thus the Creator’s moral government is conceded) looks like inherited disputational commonplaces: the goal is not rhetorical flourish but systematic foreclosure of Marcionite exits by exhausting the interpretive options one by one. That is exactly the kind of “refutation from what they still retain” promised by Irenaeus, and the alternation of beatitude/woe functions as a ready-made test-case for the unity of goodness and judgment that Book IV of Irenaeus repeatedly defends against Marcionite division.
Condensed assessment. IV.15 strongly supports dependence on an earlier Irenaean anti-Marcionite framework insofar as its central engine is the Irenaean method announced in III.12.12—convicting Marcion from the retained Gospel by demonstrating that the same Christ-voice must both bless and threaten, thereby reinstating the one Creator as simultaneously beneficent and judicial, a hallmark of Irenaeus’s sustained anti-Marcionite argumentation.