From the OT, through the NT till the present day the Church has taught that abortion is intrinsically evil, equal to murder since it is a deliberate termination of another life. The Church believes, as taught in the Scriptures that life begins from conception. If the Child in the womb is able to “grow”, then that means the child’s alive, and it cannot be alive lest it has a soul, its animating principle.
John Paul II’s Evangelium Vitae (no 62) says:
The more recent Papal Magisterium has vigorously reaffirmed this common doctrine. Pius XI in particular, in his Encyclical Casti Connubii, rejected the specious justifications of abortion. Pius XII excluded all direct abortion, i.e., every act tending directly to destroy human life in the womb "whether such destruction is intended as an end or only as a means to an end”. John XXIII reaffirmed that human life is sacred because "from its very beginning it directly involves God's creative activity”. The Second Vatican Council, as mentioned earlier, sternly condemned abortion: "From the moment of its conception life must be guarded with the greatest care, while abortion and infanticide are unspeakable crimes". The Church's canonical discipline, from the earliest centuries, has inflicted penal sanctions on those guilty of abortion. This practice, with more or less severe penalties, has been confirmed in various periods of history. The 1917 Code of Canon Law punished abortion with excommunication. The revised canonical legislation continues this tradition when it decrees that "a person who actually procures an abortion incurs automatic (latae sententiae) excommunication". The excommu- nication affects all those who commit this crime with knowledge of the penalty attached, and thus includes those accomplices without whose help the crime would not have been committed. By this reiterated sanction, the Church makes clear that abortion is a most serious and dangerous crime, thereby encouraging those who commit it to seek without delay the path of conversion. In the Church the purpose of the penalty of excommunication is to make an individual fully aware of the gravity of a certain sin and then to foster genuine conversion and repentance. Given such unanimity in the doctrinal and disciplinary tradition of the Church, Paul VI was able to declare that this tradition is unchanged and unchangeable. Therefore, by the authority which Christ conferred upon Peter and his Successors, in communion with the Bishops-who on various occasions have condemned abortion and who in the aforementioned consultation, albeit dispersed throughout the world, have shown unanimous agreement concerning this doctrine-I declare that direct abortion, that is, abortion willed as an end or as a means, always constitutes a grave moral disorder, since it is the deliberate killing of an innocent human being. This doctrine is based upon the natural law and upon the written Word of God, is transmitted by the Church's Tradition and taught by the ordinary and universal Magisterium. No circumstance, no purpose, no law whatsoever can ever make licit an act which is intrinsically illicit, since it is contrary to the Law of God which is written in every human heart, knowable by reason itself, and proclaimed by the Church.
“The second commandment of the teaching: You shall not murder. You shall not commit adultery. You shall not seduce boys. You shall not commit fornication. You shall not steal. You shall not practice magic. You shall not use potions. You shall not procure [an] abortion, nor destroy a newborn child” (Didache 2:1–2 [A.D. 70]).
The Letter of Barnabas
“The way of light, then, is as follows. If anyone desires to travel to the appointed place, he must be zealous in his works. The knowledge, therefore, which is given to us for the purpose of walking in this way, is the following. . . . Thou shalt not slay the child by procuring abortion; nor, again, shalt thou destroy it after it is born” (Letter of Barnabas 19 [A.D. 74]).
The Apocalypse of Peter
“And near that place I saw another strait place . . . and there sat women. . . . And over against them many children who were born to them out of due time sat crying. And there came forth from them rays of fire and smote the women in the eyes. And these were the accursed who conceived and caused abortion” (The Apocalypse of Peter 25 [A.D. 137]).
“What man of sound mind, therefore, will affirm, while such is our character, that we are murderers?
. . . [W]hen we say that those women who use drugs to bring on abortion commit murder, and will have to give an account to God for the abortion, on what principle should we commit murder? For it does not belong to the same person to regard the very fetus in the womb as a created being, and therefore an object of God’s care, and when it has passed into life, to kill it; and not to expose an infant, because those who expose them are chargeable with child-murder, and on the other hand, when it has been reared to destroy it” (A Plea for the Christians 35 [A.D. 177]).
“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 9:8 [A.D. 197]).
“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 [of the child] within the womb are dissected with anxious but unfaltering care; its last appendage being a blunted or covered hook, wherewith the entire fetus 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, [meaning] “the slayer of the infant,” which of course was alive. . . .
“[The doctors who performed abortions] all knew well enough that a living being had been conceived, and [they] pitied this most luckless infant state, which had first to be put to death, to escape being tortured alive” (The Soul 25 [A.D. 210]).
“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” (ibid., 27).
“The law of Moses, indeed, punishes with due penalties the man who shall cause abortion [Ex. 21:22–24]” (ibid., 37).
“There are some [pagan] women who, by drinking medical preparations, extinguish the source of the future man in their very bowels and thus commit a parricide before they bring forth. And these things assuredly come down from the teaching of your [false] gods. . . . To us [Christians] it is not lawful either to see or hear of homicide” (Octavius 30 [A.D. 226]).
“Women who were reputed to be believers began to take drugs to render themselves sterile, and to bind themselves tightly so as to expel what was being conceived, since they would not, on account of relatives and excess wealth, want to have a child by a slave or by any insignificant person. See, then, into what great impiety that lawless one has proceeded, by teaching adultery and murder at the same time!” (Refutation of All Heresies [A.D. 228]).
Council of Ancyra
“Concerning women who commit fornication, and destroy that which they have conceived, or who are employed in making drugs for abortion, a former decree excluded them until the hour of death, and to this some have assented. Nevertheless, being desirous to use somewhat greater lenity, we have ordained that they fulfill ten years [of penance], according to the prescribed degrees” (canon 21 [A.D. 314]).
Basil the Great
“Let her that procures abortion undergo ten years’ penance, whether the embryo were perfectly formed, or not” (First Canonical Letter, canon 2 [A.D. 374]).
“He that kills another with a sword, or hurls an axe at his own wife and kills her, is guilty of willful murder; not he who throws a stone at a dog, and unintentionally kills a man, or who corrects one with a rod, or scourge, in order to reform him, or who kills a man in his own defense, when he only designed to hurt him. But the man, or woman, is a murderer that gives a philtrum, if the man that takes it dies upon it; so are they who take medicines to procure abortion; and so are they who kill on the highway, and rapparees” (ibid., canon 8).
“Wherefore I beseech you, flee fornication. . . . Why sow where the ground makes it its care to destroy the fruit?—where there are many efforts at abortion?—where there is murder before the birth? For even the harlot you do not let continue a mere harlot, but make her a murderess also. You see how drunkenness leads to prostitution, prostitution to adultery, adultery to murder; or rather to a something even worse than murder. For I have no name to give it, since it does not take off the thing born, but prevents its being born. Why then do thou abuse the gift of God, and fight with his laws, and follow after what is a curse as if a blessing, and make the chamber of procreation a chamber for murder, and arm the woman that was given for childbearing unto slaughter? For with a view to drawing more money by being agreeable and an object of longing to her lovers, even this she is not backward to do, so heaping upon thy head a great pile of fire. For even if the daring deed be hers, yet the causing of it is thine” (Homilies on Romans 24 [A.D. 391]).
“I cannot bring myself to speak of the many virgins who daily fall and are lost to the bosom of the Church, their mother. . . . Some go so far as to take potions, that they may insure barrenness, and thus murder human beings almost before their conception. Some, when they find themselves with child through their sin, use drugs to procure abortion, and when, as often happens, they die with their offspring, they enter the lower world laden with the guilt not only of adultery against Christ but also of suicide and child murder” (Letters 22:13 [A.D. 396]).
The Apostolic Constitutions
“Thou shalt not use magic. Thou shalt not use witchcraft; for he says, ‘You shall not suffer a witch to live’ [Ex. 22:18]. Thou shall not slay thy child by causing abortion, nor kill that which is begotten. . . . [I]f it be slain, [it] shall be avenged, as being unjustly destroyed” (Apostolic Constitutions 7:3 [A.D. 400]).