Q - I was having an interesting conversation with someone about Catholic theology when the subject of abortion came up. His train of thought led from supporting evolution to defining what it is to be human, and from this came: "when does life actually start?" I think (and I'm not all that sure) that Catholic teaching says life starts at conception. If so, how do we know this, or why do we believe it? Even when the embryo is only 8 cells, is it considered "life"?
A - Thanks for the question! Remember that nobody has all the right answers and that your witness to faith is more important than your precision in answering questions. So, good job!
You certainly have the right instincts about this issue. The consensus, philosophically, morally and scientifically, is that human life begins at conception. It can be nothing else. What else could it be? There is no good answer to that question. "Potential human life" makes no sense. It either is or isn't a human life. It isn't dead, rather another life is present, so the question really becomes - what makes this a "human" life?
Is it self-consciousness that makes us human or maybe the ability to think? Then are those in brain-dead comas no longer human, even if they wake later?
Is it viability of the fetus? Then what about anyone who can't live without another? Are they not human unless they can tend for themselves?
Even if there is doubt (and I don't believe there is) about when human life begins, why take the chance? In other words, I wouldn't risk practice-shooting in my backyard unless I knew that my kids weren't anywhere near the target. So, why do we risk the life of another in regards to abortion, even if someone isn't sure about when life begins.
The Catechism defines human life as it begins in conception:
1703 Endowed with "a spiritual and immortal" soul, the human person is "the only creature on earth that God has willed for its own sake." From his conception, he is destined for eternal beatitude.So, how do we know this?
1711 Endowed with a spiritual soul, with intellect and with free will, the human person is from his very conception ordered to God and destined for eternal beatitude. He pursues his perfection in "seeking and loving what is true and good"
2270 Human life must be respected and protected absolutely from the moment of conception. From the first moment of his existence, a human being must be recognized as having the rights of a person - among which is the inviolable right of every innocent being to life.
We know it by reason. A human being is the only thing an 8-celled embryo could be. It cannot develop into anything other than a full-grown human - if given enough time, a proper environment and nourishment.
Here is a great article, that I will quote a short part of:
Here is a great video explanation:When does life begin?
Some people claim that our human lives really do not begin at fertilization, and that a more realistic time for the dignity of "humanity" to be imparted on a growing blastocyst-embryo would be about a week after fertilization, about the time of implantation.
It does not change things that in centuries past, some great Catholic theologians and philosophers differed on when precisely a biological entity becomes infused with a human soul. St. Thomas Aquinas, using the limited scientific knowledge of the 13th century, followed Aristotle that the conception of a male child was completed at day 40, and that of the female child at the 90th day, with replacement of the embryo's “nutritive soul” by a human soul. The Venerable Maria de Agreda, a 17th-century visionary, wrote that human "ensoulment" occurs at different times for boys and girls, and that it occurs at a time later than fertilization.
I am not a philosopher or theologian but a student of medicine and surgery. I can speak to you with authority that from a pure, unadulterated biological and embryological standpoint, there is no greater pivotal moment in our growth and development than when 23 chromosomes from our father join with 23 chromosomes from our mother to form a unique, new biologic entity who heretofore simply had not existed.
This new biological individual is complete, has a gender, and is fully and uniquely programmed and equipped to grow and develop and change until death. All he or she needs is nutrition and a warm place to grow. To say that an embryo has the "potential" to become a human being is biologically and technically imprecise – and dangerous.
Perhaps even more dangerous is the concept that it is not a precise moment, but a gradation of human worth. With this model, a preborn baby at 3 months is somewhat of a human being, but a newborn is more of a human being.
So -- is a 10-year-old boy or girl more a human being than a 1-year-old? Is a politician or athlete more a human being than a wheelchair-bound paraplegic? Can we really stratify intrinsic human dignity and worth? Is human equality a myth? This sort of thinking forms the basis for demeaning entire classes of people. Ultimately, it denies them their humanity. The 20th century gave ample evidence of the depravity of such thinking.
It is not “potential to become a person” that entitles a human embryo to legal and moral status. It is part of the fabric of natural and biological law that the human embryo’s actuality of being human entitles him or her to legal and moral status (8).