As a preacher and theologian, Tertullian (c. 150 – c. 229) taunted the Roman Empire at every turn, defended believers against the persecution of the state, and often reprimanded Christians for compromising their faith. Famous for his faithfulness (an early developer of the doctrine of the “Trinity”) and his failures (his joining with the Montanists—a group who believed in extra-biblical revelation), Tertullian would not allow abortion to remain unchallenged by the Church.
In our case, murder being once for all forbidden, we may not destroy even the foetus in the womb, while as yet the human being derives blood from other parts of the body for its sustenance. To hinder a birth is merely a speedier man-killing; nor does it matter whether you take away a life that is born, or destroy one that is coming to the birth. That is a man which is going to be one; you have the fruit already in its seed.1
1 Tertullian, Apology, in The Ante-Nicene Fathers, vol. 3 (Grand Rapids, MI: Wm. B. Eerdmans Publishing Company, 1957), 25. In other translations, see Chapter 9.