Tertullian, Quintus Septimus Florens (c. AD 160–c. AD 220)

Tertullian was the first Christian theological author to write in Latin, and is responsible for initiating the Latin vocabulary of Christian theology, including such important terms as persona (person) and substantia (substance). His early works, including the Apologeticum, refute pagan misconceptions about Christianity and argue on philosophical and juridical grounds for religious freedom. His later theological treatises, such as De anima (On the Soul) and Adversus Marcionem (Against Marcion) reflect Tertullian’s adherence, in about ad 205–6, to Montanism, a Christian sect which emphasized asceticism, apocalypticism and prophecy. These lengthy works represent an effort to oppose those forms of Christianity that sought to ally themselves with Platonism, such as Gnosticism. After these defences of apocalyptic Christianity, Tertullian fades from historical view around ad 220, leaving a legacy of charismatic truculence.