"IN our case, a murder being once for all forbidden, we may not destroy even the fetus in the womb, while as yet the human being derives blood from the 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 birth. That is a man which is going to be one; you have the fruit already in its seed." --Apology, Ch. 9, v. 8. (A.D. 197)
"ACCORDINGLY, among surgeons' tools there is a certain instrument, which is formed with a nicely-adjusted flexible frame for opening the uterus first of all, and keeping it open; it is further furnished with an annular blade, by means of which the limbs within the womb are dissected with anxious but unfaltering care; its last appendage being a blunted or covered hook, wherewith the entire fœtus is extracted by a violent delivery. There is also (another instrument in the shape of) a copper needle or spike, by which the actual death is managed in this furtive robbery of life: they give it, from its infanticide function, the name of embruosphaktes [ἐμβρυοσφάκτης], the slayer of the infant, which was of course alive." --Treatise on the Soul, Chap. 25; (A.D. 210)
"HOW, then, is a living being conceived? Is the substance of both body and soul formed together at one and the same time? Or does one of them precede the other in natural formation? We indeed maintain that both are conceived, and formed, and perfectly simultaneously, as well as born together; and that not a moment's interval occurs in their conception, so that, a prior place can be assigned to either. Judge, in fact, of the incidents of man's earliest existence by those which occur to him at the very last. As death is defined to be nothing else than the separation of body and soul, life, which is the opposite of death, is susceptible of no other definition than the conjunction of body and soul. If the severance happens at one and the same time to both substances by means of death, so the law of their combination ought to assure us that it occurs simultaneously to the two substances by means of life. Now we allow that life begins with conception, because we contend that the soul also begins from conception; life taking its commencement at the same moment and place that the soul does;" --Treatise on the Soul, Chap. 27.
"THE law of Moses, indeed, punishes with due penalties the man who shall cause abortion[Ex. 21:22–24], inasmuch as there exists already the rudiment of a human being, which has imputed to it even now the condition of life and death, since it is already liable to the issues of both, although, by living still in the mother, it for the most part shares its own state with the mother." --Treatise on the Soul, Chap. 37.
~Tertullian (Quintus Septimius Florens Tertullianus)
