Tertullian (160?-220?), the first important Christian ecclesiastical writer in Latin, whose work is remarkable for its blunt sarcasm, epigrammatic phrasing, aggressive partisan spirit, and skillful—though sometimes specious—reasoning. Tertullian was born Quintus Septimius Florens Tertullianus in Carthage, the son of a Roman centurion. He trained for a career in law and practiced his profession in Rome. Sometime between 190 and 195, while still in Rome, he became a convert to the Christian faith, and it is evident that he visited Greece and possibly Asia Minor. In 197 he returned to Carthage, where he married and became a presbyter of the church. About 207 he aligned himself with Montanism, a sect that encouraged prophesying and espoused a rigorous form of asceticism. The Montanists, increasingly in conflict with church authorities, were finally declared heretical.

A zealous champion of Christianity, Tertullian wrote many theological treatises, of which 31 have survived. In his various works he strove either to defend Christianity, to refute heresy, or to argue some practical point of morality or church discipline. His views on ethics and discipline, rigorously ascetic from the first, became progressively more harsh in his later works. After espousing Montanist doctrines, he was a severe critic of orthodox Christians, whom he accused of moral laxity.

Tertullian profoundly influenced the later church fathers, especially Saint Cyprian—and through them, all Christian theologians of the West. Many of his works are accepted as orthodox by the Roman Catholic church and are included in the recognized body of patristic literature.

Tertullian’s writings demonstrate a profound knowledge of Greek and Latin literature, both pagan and Christian. He was the first writer in Latin to formulate Christian theological concepts, such as the nature of the Trinity. Having no models to follow, he developed a terminology derived from many sources, chiefly Greek and the legal vocabulary of Rome. His legal turn of mind imprinted on this newly minted theological language of the West a juridical character that has never been erased.

The most famous work by Tertullian is Apologeticus (197?), an impassioned defense of Christians against pagan charges of immorality, economic worthlessness, and political subversion. Of his doctrinal treatises refuting heresy, the most important is De Praescriptione Hereticorum (On the Claims of Heretics), in which he argued that the church alone has the authority to declare what is and is not orthodox Christianity. In other writings he strongly disapproved of second marriages, exhorted Christians not to attend public shows, and favored simplicity of dress and strict fasts. Like all Montanists, Tertullian held that Christians should welcome persecution, not flee from it. Christian historians value many of his writings, especially De Baptismo (On Baptism) and De Oratione (On Prayer), for the light they throw on contemporary religious practices.