Tertullian

“ We now maintain their conjunction likewise from the birth onwards; in the first place, because they both grow together, only each in a different manner suited to the diversity of their nature—the flesh in magnitude, the soul in intelligence—the flesh in material condition, the soul in sensibility. We are, however, forbidden to suppose that the soul increases in substance, lest it should be said also to be capable of diminution in substance, and so its extinction even should be believed to be possible ”

“ A mature and regular birth takes place, as a general rule, at the commencement of the tenth month. They who theorize respecting numbers, honour the number ten as the parent of all the others, and as imparting perfection to the human nativity. For my own part, I prefer viewing this measure of time in reference to God, as if implying that the ten months rather initiated man into the ten commandments; so that the numerical estimate of the time needed to consummate our natural birth should correspond to the numerical classification of the rules of our regenerate life. ”

“ The embryo therefore becomes a human being in the womb from the moment that its form is completed. The law of Moses, indeed, punishes with due penalties the man who shall cause abortion, inasmuch as there exists already the rudiment of a human being, [1] 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. I must also say something about the period of the soul’s birth, that I may omit nothing incidental in the whole process. ”