Christian abortion beliefs through history

Christian teaching on abortion did not develop in a single uninterrupted line. Early sources often condemned abortion alongside infant abandonment, while later Western theology distinguished between an unformed and an ensouled fetus. By the nineteenth century, Roman Catholic discipline no longer made that distinction.

Fourth century BCE to first century CE

Aristotle's model of delayed ensoulment influenced thought in ancient Greece and Rome. In this framework, fetal development moved through vegetative and animal stages before acquiring a rational human soul. Aristotle associated this transition with approximately 40 days after conception for a male fetus and 90 days for a female fetus. These sex-based distinctions reflected assumptions of the period rather than modern embryology.

The model generally treated an early abortion differently from one performed after the presumed arrival of a human soul. Ancient people had no modern pregnancy testing or fetal imaging, so the proposed thresholds were philosophical rather than clinically observable.

Jewish legal traditions generally rejected infant abandonment and did not treat fetal life in exactly the same way as a born person. Protection of the pregnant person's life could take precedence. Philo of Alexandria, writing in the first century CE, criticized abortion and infant abandonment as practiced in surrounding cultures. See Jewish beliefs about abortion for a separate overview.

Second to fourth centuries CE

Early Christianity developed among Jewish, Greek, Roman and other religious communities. Several Christian texts opposed abortion and infant abandonment, practices that some writers associated with the wider Roman world. Their arguments commonly described fetal life as being under divine care and treated deliberate abortion as a grave moral offense.

Individual writers

• The Letter of Barnabas, usually dated to the early second century, prohibited ending fetal or newborn life.
• Athenagoras argued in a petition to the Roman emperor that inducing an abortion was inconsistent with Christian regard for life in the womb.
• Clement of Alexandria criticized abortifacient drugs and connected their use with attempts to conceal sexual conduct.
• Tertullian treated the developing fetus as human life and argued that preventing birth by killing the fetus violated the Christian prohibition on killing.
• Hippolytus, Basil, Ambrose, John Chrysostom and Jerome also condemned abortion, frequently connecting it to contemporary concerns about adultery, inheritance, social status and dangerous drugs.

Community texts and councils

• The Didache prohibited abortion and the killing of newborn children.
• The Synod of Elvira in 306 imposed a severe lifelong exclusion from communion in a case involving adultery and abortion.
• The Synod of Ancyra in 314 prescribed ten years of penance.
• The Apostolic Constitutions, compiled in the late fourth century, used fetal formation and reception of a soul as morally significant distinctions. That wording indicates that not every early source framed every stage of pregnancy identically. See the archive's fetal-development discussion.

Fifth to sixteenth centuries CE

In Western Christianity, Augustine adopted a version of delayed ensoulment. He reasoned that a rational soul could not inhabit an unformed body, so ending an early pregnancy was not classified as homicide in the same way as ending the life of an animated fetus. It could still be treated as sinful. This distinction entered Western canon-law traditions, while Eastern Orthodox Christianity retained a more consistently restrictive approach.

Jerome similarly distinguished fetal formation from an earlier developmental stage. From the seventh century onward, Western penitential manuals assigned different periods of penance to sexual acts, contraception and abortion. The variations show that classification and punishment were not uniform across periods or jurisdictions.

• Pope Stephen V wrote in 887 that destroying what had been conceived could constitute homicide.
• Pope Innocent III used animation as a distinction when considering a case involving a monk. He also associated ensoulment with quickening, when fetal movement was first felt.
• Thomas Aquinas followed an Aristotelian account in which a rational soul arrived after earlier stages of development.
• Pope Sixtus V imposed excommunication for abortion at any stage in 1588.
• Pope Gregory XIV reversed that policy in 1591 and restored a distinction based on quickening.

Seventeenth century to 1983

During the seventeenth century, the theory of immediate or simultaneous animation gained support among some European theologians and physicians. It held that the soul was present from conception rather than arriving after a developmental interval. Debate continued, and the disciplinary treatment of abortion did not change all at once.

In 1869, Pope Pius IX removed the canonical distinction between an animated and an unanimated fetus for the purpose of abortion penalties. Under Pope Leo XIII, late nineteenth-century decrees prohibited procedures that directly ended fetal life, including when they were proposed to save a pregnant patient's life. These rules established the restrictive disciplinary framework associated with subsequent Roman Catholic teaching.

Canon law was revised in 1917 and again in 1983. Its abortion provisions referred to the fetus without restoring the earlier ensoulment thresholds. For the related doctrinal summary, read Roman Catholic teaching on abortion and historical discussions of exceptions.

References used in the archive

1. Aristotle, History of Animals, Book VII, chapter 3, 583b.
2. Philo of Alexandria, On the Special Laws, Book III.
3. Uta Ranke-Heinemann, Eunuchs for the Kingdom of Heaven: Women, Sexuality and the Catholic Church (1990), pp. 68–70 and 298–311.
4. Tertullian, Apology, chapter 9.
5. Minucius Felix, Octavius, chapter 30.
6. Ambrose, Hexaemeron, Book V.
7. Augustine, Questions on Exodus, question 80.
8. Jerome, Letter 121.