Tertullian

← Encyclopedia

Tertullian — Quintus Septimius Florens Tertullianus — was a Latin Christian writer active in Carthage around the turn of the third century, and the first theologian of consequence to write in Latin rather than Greek. Much of his life is uncertain: the dates conventionally given, roughly 155 to 240, are inferred rather than recorded, and the old report that he was a trained lawyer rests on thin evidence. What survives is the work — some thirty treatises, argumentative, mordant, and unmistakably his.

His importance is partly linguistic. Writing for a Latin-speaking church that had inherited its theology in Greek, he had to make a vocabulary as he went, and a great deal of later Western Christian terminology descends from his coinages and calques. The Latin words behind Trinity, person, and substance enter Christian usage in something close to their durable form through him; his formulations of how the one God could be spoken of as three did real work in later doctrinal disputes, even where the church’s eventual settlements diverged from his own.

He wrote on every front at once. The Apology defended Christians against Roman suspicion and the charge of disloyalty; a long series of polemics went after opponents inside the faith — most extensively Marcion, who had severed the Hebrew scriptures and their God from the gospel, and the Valentinian Gnostics, whose elaborate cosmologies Tertullian reported in order to ridicule. With Irenaeus before him and Hippolytus alongside, he is one of the heresiologists through whose hostile summaries much of what is known of second-century Gnosticism reaches us at all — a source to be used and distrusted in the same motion, since his aim was refutation, not record.

A famous line is often hung on him: the demand credo quia absurdum, “I believe because it is absurd.” He did not write those exact words; what he wrote, of the crucified and risen Christ, was that it is to be believed because it is unfitting, certain because impossible. The paraphrase has stuck because it catches something real in him — a willingness to set faith against the respectable reasoning of the schools, captured in his sharper question, what has Athens to do with Jerusalem?

Late in life he drew toward Montanism, a rigorist prophetic movement that claimed fresh outpourings of the Spirit and held the established church too lax. How far he broke with it is debated; the later notion of a distinct “Tertullianist” sect is doubtful. The trajectory fits the man the writings show: exacting, combative, impatient with compromise. The church that built so much of its language on his never canonized him, and the discomfort was mutual.

→ In the library: Mead — Fragments of a Faith Forgotten: The Gnosis According to its Foes

→ Related: Irenaeus · Hippolytus · Origen · Gnosis