Tertullian wrote in a wirry and vigorous style, marked by startling turns of phrase. It was he who claimed that “the blood of the martyrs is seed”. But his well-known question, “What has Athens to do with Jerusalem?” expressed a rejection of philosophy that was not true of his own work, since he demonstrated how pagan intellectual achievements could be made to serve Christianity.
Tertullian’s masterpiece was the Apology, which argued effectively that Christianity should be tolerated. His longest work, the five books Against Praxeas, Tertullian developed the doctrine of the Trinity. Tertullian had two things against Praxeas: his opposition to the Montanist “New Prophecy”, and his view of God. Tertullian said that Praxeas “did two works for the Davil in Rome: he put to flight the Paraclete and crucified the Father.”