Human personhood begins at fertilization

Anthony Zimmerman
Not published.
December 30, 2002
Reproduced with Permission

Death, we know, occurs in that instant when the soul leaves the body. Can we identify with like assurance an instant when the life of a person begins? Despite contrary fudging by the USA Supreme Court and sundry ethicists, the answer is yes. Human personhood begins at fertilization. At that instant God animates with a spiritual soul a viable integrated sperm and ovum. Such is the thrust of what follows in this article. It is a response to an article published by Fr. Juan Masia, SJ, in the Japan Mission Journal, Spring 2002.

The Supreme Court of the USA, in its catastrophic decision to legalize abortion in 1973, wrote as follows: "We need not resolve the difficult question of when life begins. When those trained in the respective disciplines of medicine, philosophy and theology are unable to arrive at any consensus, the judiciary, at this point in the development of man's knowledge, is not in a position to speculate as to the answer." But despite this alleged lack the judges themselves pontificated that the human fetus is only "potential human life", or a "potential person". With that declaration an instrument of mass destruction of unborn children burst upon the USA and from there infested a large part of the human race. The decision made by the judges was not based upon science, nor likely upon ignorance, but upon an arbitrary exercise of raw power.

Are embryos people? What do human embryologists say?

Dianne N. Irving, Ph.D., who is an articulate scientist and philosopher, and a former research biochemist at the National Institute of Health, Bethesda, Maryland, USA, rightly insists that ethical evaluation must begin with correct facts. She writes:

One of the most urgent yet least discussed dilemmas concerning the woman, the physician, and a host of others facing abortion today, is access to the correct basic scientific information regarding the human embryo -- scientific information which demonstrates empirically that normally every human being begins at fertilization as a single-cell embryo, the zygote. Without this correct scientific information we are all precluded from forming our consciences correctly or making morally correct decisions about abortion, human embryo research, human embryonic stem cell research, cloning, formation of interspecies chimeras, germ-line DNA recombinant gene research and therapy, and other related current medical and scientific issues. The use of the correct science is indeed the starting point for thinking about all of this, short of Divine Revelation.(1)

In testimony presented to the Philippine government, Bureau of Food and Drug, August 28, 2001, Dr. Irving quoted excerpts from representative current text books on human embryology, those used in standard class-room teaching. They explain that human beings begin their individual lives at the time of fertilization. The government of the Philippines thereupon banned the "morning after pill" from use in the nation because it is abortifacient, and therefore against the Constitutions.

Dr. Irving annotated the credentials of these authors in a letter containing the testimony:

The scientific experts who are the experts on the issue of when a human being begins to exist, and on subsequent early human development from fertilization on, are human embryologists.... It needs to be realized that in the science of human embryology these scientific experts are professionally required to follow definitions of terms according to an International Nomina Embryologica Committee [INEC]. This international committee meets every 3-5 years to examine, update and clarify which human embryological facts are scientifically demonstrated, accurate, and acceptable for human embryologists worldwide to employ in their own research, teaching and textbooks. In other words, these scientific definitions are not arbitrary, nor are they "relative". And among human embryologists globally there is 100% consensus on these objective scientific facts. If other scientists and physicians are not aware of these scientific facts, that is more a reflection of their lack of knowledge and/or credentials, rather than a reflection of any "confusion" on these scientific facts.

Due to its actual abortifacient properties, on Dec. 7, 2001, the Philippine government agreed to ban the sale and distribution of Postinor, a "morning-after" pill, or "emergency contraceptive" pill. This official action followed a successful law suit brought before the government by attorney Jo Aurea M. Imbong of the Abaypalilya Foundation, Inc., in the Philippines.

What follows is a sample of the testimony that Dr. Irving supplied for the suit which successfully banned the morning after pill in the Philippines because it causes abortions and is therefore forbidden by the Philippine Constitutions:

To demonstrate scientifically that normally a human being begins to exist at fertilization, please allow me to quote directly from several current human embryology textbooks (two of which are authored by members of the INEC: Moore and O'Rahilly). Note that O'Rahilly actually rejects the use of the false term "pre-embryo" in his human embryology textbook. These quotations also demonstrate scientifically that fertilization is also the beginning of the existence of a human individual, a human organism, a human embryo, normal human pregnancy, and the "embryonic period."

She then quotes paragraphs from four current and representative texts on Embryology, standard texts used in classrooms. All have one and the same information namely that human development is a continuous process that begins when an oocyte from a female is fertilized by a spermatozoon from a male. The single cell zygote (the first cell) is the beginning of a new human being. This highly specialized, totipotent cell marks the beginning of each of us as a unique individual. Dr. Irving notes that the term "pre-embryo" is not used by embryologists.

The beginning of a human person is instantaneous, is not a gradual process

The beginning of a human life cannot be other than a single flash of instantaneous occurrence. It cannot be a gradual process. The moment cannot be stretched out over "more than twenty hours" (see The Japan Missionary Journal, Spring 2002, p. 12). When God creates human life, He inserts this person into our cosmos in an instant of our revolving time, not gradually, piece by piece. There is no gradation of first 10% person, then 20% some two hours later, and finally 100% at completion of the creative act. A spiritual soul is a simultaneous unity, one integral spiritual substance, not by itself composed of parts, although it animates bodily parts.

Scientifically speaking, therefore, there is just one moment when human life begins. The soul is whole and entire in every part of the human body, but the soul itself is not composed of the parts which it animates. The soul integrates the body into one system, is co-extensive with the body which it animates, but is not divisible as are the materials of the body. When part of the body is amputated, the soul is no longer in the separated limb. When tissue is taken to the laboratory for inspection and cultivation, the soul is not in that living tissue.

The concept of a gradual creation of the soul stretched out over time is not logical. Up to the instant of its creation, the soul "is not". With the instant of creation it "is". God says: "Let this soul be" and there is this soul. It does not pre-exist somewhere in eternity or in space, awaiting its turn to be inserted into a body.

Tertullian's error: fathers beget the souls of their children

Tertullian (c.160-220) was a Roman Lawyer of note who invented a theory called "Traducianism". It stated that fathers beget the souls of their children as well as the bodies. He started with original sin, saying that Adam polluted his soul with original sin, and then passed the sin on to his children when he begot their souls from his own. He writes in De Anima that the male ejaculate contains two seeds, one for the body, a second for the soul of the offspring:

For although we shall allow that there are two kinds of seed that of the body and that of the soul we still declare that they are inseparable, and therefore contemporaneous and simultaneous in origin... The two substances, although diverse from each other, flow forth simultaneously in a united channel; and finding their way together into their appointed seed-plot, they fertilize with their combined vigour the human fruit out of their respective natures... Accordingly from the one (primeval) man comes the entire outflow and redundance of men's souls...

Tertullian was wrong, of course. Lactantius was quick to repudiate him, and the doctrine of Traducianism did not become a part of Church teaching. Souls cannot produce other souls, declared Lactantius:

A question also may arise respecting this, whether the soul is produced from the father, or rather from the mother, or indeed from both... Nothing is true of these three opinions, because souls are produced neither from both nor from either. For a body may be produced from a body, since something is contributed from both; but a soul cannot be produced from souls, because nothing can depart from a slight and incomprehensible subject. Therefore the manner of the production of souls belongs entirely to God alone (De opif. 19).

By what life do sperm and ovum live?

It appears to me that we might roughly equate the lives of sperm and ovum to that of bodily tissue separated from the body itself, being no longer animated by the souls of either parent. Sperm, once separated from a man's body can live a "sperm" life for some days in a woman's body or in a Petri dish. It dies if it does not fertilize an ovum. The ovum "life cycle" is shorter than that of the sperm. When it leaves its follicle to be drawn into the Fallopian tube it appears to function on its own life separated from the life of the mother. It has a short life expectation of twenty four hours at most if it is not rescued by a sperm. This fragile and temporary life suggests that it is no longer animated by the soul of the mother.

Might we then speculate that the initial life of an embryo is temporary, not yet animated by a spiritual soul? Two responses may be given: first of all, embryologists see a single continuum of bodily development after fertilization. They see no evidence of a break in the continuum which might lead to a suggestion that a soul is infused into an embryo at some time after fertilization. The evidence for such an hypothesis is totally lacking.

Second, the initial human cell is a specific human cell, with its species specific enzymes and proteins, and with DNA plans for the eventual development of a human brain. The end - the development of that brain - cannot be something extrinsic to the capacity of its initial generation. An "animal embryo" with DNA for a human brain would carry an "overload." It would be like putting a mouse into the pilot seat of a commercial airliner. An embryo without the DNA of a human brain would remain an animal forever. A mouse embryo will not change into a human embryo. An embryo with DNA for a human brain is already a human person. If a change would occur during development from an "animal" embryo into a "human" embryo, the DNA for producing the human brain would have to be added later. Such an addition of genetic materials is not observed by scientists. We conclude that, since the genome for human brain development is present in a human zygote, a spiritual soul animates that zygote.

The process leading to fertilization

There is a remarkable instantaneous change in the ovum at the instant the sperm enters into it. The ovum instantaneously hardens its shell by a release of ions, and isolates itself from the outside world to live together with its newly enclosed sperm. One person wrote about seeing it happen on a TV exhibit:

Do you know, I have actually seen this happen on TV? The very instant that the FIRST sperm cell enters the egg, the egg wall turns hard and opaque. So I have seen it with my own eyes: biologically, the fertilized egg instantly knows itself to be a unique individual, and immediately asserts its rights to an unviolated integrity. Our libertarian friends who are so interested in the rights of individuals to be left alone should be keenly interested that the assertion of this right is the instantaneous first act of the fertilized ovum.

Scientists Serra and Colombo: life begins at fertilization

Geneticist Angelo Serra and bioethicist Roberto Colombo related to the Pontifical Academy of Life in February of 1997 what science currently knows about the process of human fertilization and subsequent development. In essence they inform us that fertilization marks the beginning of a new human life who is an individual person. Allow me to restate their science as found in their article "The Epigenesis of the Embryo" in the book, The Identity and Status of the Human Embryo (2).

They tell us that the conception of a human being follows a pathway of several steps that occur in compulsory order. The process starts as soon as a sperm associates with the ovum in the latterŐs thick coat called the zona pellucida. The action of the sperm dissolves a passageway, and the receptors of the zona propel the sperm on its way to the goal. The speed is about one micron per minute. A micron is one millionth of a meter. So the sperm burrows its way through the zona by dissolving it, and the receiving ovum draws it on with its corresponding receptors. A number of sperms may be engaged in the process at the same time.

When the first spermatozoon reaches the perivitelline space between the zona pellucida and the membrane that encloses the plasma of the ovum, it can finally make direct contact with that authentic membrane of the ovum. The instant of contact triggers immediate action, a coordinate cascade of events. Microvilli and contracticle proteins - actin and mysin - of the ovum propel the sperm into the plasma of the ovum. Then the ovum slams the gate shut. Under the action of oscilline, a propagation of a calcium wave blitzes around the fertilized ovum to instantly harden its shell thereby preventing penetration by other sperms which have lost the race. The receptors of the zona pellucida which had helped the first sperm to penetrate its coat are neutralized, no longer helpful to subsequent sperms. Call it slamming the door and waving the other suitors away. Bear with me as I quote from their article:

That new cell is the zygote, the one-cell embryo: a new cell that starts to operate as a unique system, i.e. as a unit, a living being ontologically one, essentially similar - although with some peculiarities - to any other cell in the mitotic phase. One of the first activities is the cortical reaction, due to secretion of hydrolytic enzymes - such as proteinases, peroxidases and other en-zymes - from the thousands of lysosome - like cortical granules, leading not only to inactivation of sperm receptors in the zona pellucida and to its hardening, but mainly to isolation and protection of the new being that initiates its own life cycle (ibid p. 151).

The above description of the process of fertilization pin-points, we are led to believe, the exact moment when the combined gametes meld their lives together. It is the moment when the sperm has passed through the thick zona pellucida, has reached the perivitellum space between the zona and the membrane containing the ovum. When sperm contacts ovum and the ovum draws it into its cell plasma, then hardens its shell and ceases to assist other sperms to enter, that is the moment of fertilization. If the matter of the combined sperm and oocyte are appropriately organized, that is, if the biological and genetic materials presented are authentically apt for animation by a human soul, that is the moment, so we can believe, when God co-creates. He cooperates with the human parents in reproduction by creating the immortal soul. God descends from eternity into time to work a miracle. He animates the fused gametes with a soul created out of nothing - just now.

Early pregnancy factor

Within 6 to 24 hours after fertilization the zygote sends a hormone to the ovary of the mother called the "ovum factor" in order to protect its newly created life. Little is known about this ovum factor except that it has a relatively small molecular mass and that it is secreted by the ovum soon after sperm penetration (3). In response to the stimulus of the ovum factor from the zygote, the mother's ovary secretes a product into the blood stream called the "Early Pregnancy Factor." The EPF has been found in serum within 6 to 24 hours of fertilization, in mice, pigs, sheep, and humans. The ovaries then secrete the early pregnancy factor into the blood circulation, and the lymph glands pick it up with their receptors. They respond by releasing immuno-suppressor factors which protect the zygote from being attacked and destroyed by the mother's immune system because he or she is a foreign body. He or she is not a part of the mother, and is a foreign body with elements from the father. EPF is also a growth factor, facilitating cell division. The newly conceived child continues to secrete its signal until the blastocyst stage. Thereafter the mother's ovaries take over entirely and continue to secrete the protective EPF for the duration of the pregnancy.

The ovum factor that the zygote secretes is a biological identification which the child gives to its mother, a name tag, a sample of this unique, one and only child's body. The mother's body, in response, protects the child from immuno-marauders, and supports the child's growth with substances sent to the growing child from her body.

Development after the fertilization event

The above mentioned article in JMJ cites opinions of several theologians that the early embryo is not yet an individual. It is unfortunate that they cite only theologians, whereas they ignore scientists. As proof, the non-scientist theologians point out that two early embryos can be fused into one, and one early embryo can divide into twins. Their writings, however, date to 1984 and 1988. Scientists today recognize that embryos begin as individuals. If twinning occurs, a second embryo splits from the individual by asexual reproduction. The original remains, and a new individual is generated. If re-absorption occurs, one of the two original individuals dies, the other survives. Embryologists now unanimously state that the zygote and early embryo are individuals. They are organizations functioning as an integrated single body, not at all as an unorganized conglomeration of disassociated individual cells.

Scientists Serra and Colombo describe and declare that the zygote is indeed an individual human being from the time of fertilization:

In order to better understand the very nature of this new cell, two main features are to be emphasized... The first feature is that the zygote exists and operates from syn-gamy on as a being ontologically one, and with a precise identity. The second feature is that the zygote is intrinsically oriented and determined to a definite development. Both identity and orientation are due essentially to the genetic information with which it is endowed. This information, substantially invari-ant, is actually the basis of its specific human appurtenance, of its individual singularity or identity, and carries a full coded program which endows it with enormous morphogenetic potentialities which will autonomously and gradually be fulfilled during the rigorously oriented epigenetic process. These potentialities do not mean pure "possibilities", but intrinsic natural capacities of an already existing being to realize, given the due conditions, the whole coded plan (p. 141).

Serra and Colombo then draw the philosophical conclusion that the zygote is a human person. When scientists see that a single-celled human zygote acts as an ontological unit of life, that it does the cortical reaction by secretion of specifically human hydrolytic enzymes such as proteinases, peroxidases and other enzymes from the thousands of lysosome-like cortical granules, to inactivate sperm receptors in the human zona pellucida, they know that all these are specifically human substances, human proteins and enzymes, and that the zygote has isolated itself effectively to live a life of its own, and that it is alive, then scientists conclude that this is a single human being of its own. Life is there, because it is self-moving. The life is human because the biological and genetic factors are specifically human. Unlike the Supreme Court Judges, these scientists see exactly when human life begins, and declare it to be so: a human person begins as a zygote, nine months before birth.


Unless God had created us, we would not be

Louise Brown, the first human to come to life in a Petri dish, is now 23 years old, a human person like every other citizen in the United Kingdom. When Dr. Robert Edwards manipulated human gametes in a Petri dish in 1978, he may have seen her come to life through a microscope. At that moment God came into his laboratory and procreated Louise Brown. It would have been proper for him to bless himself, light a candle, and kneel down to adore the Lord of Creation. The Catechism states that humans come to life via the soul that God creates:

364 The human body shares in the dignity of "the image of God": it is a human body precisely because it is animated by a spiritual soul ...

366 The Church teaches that every spiritual soul is created immediately by God - it is not "produced" by the parents - and also that it is immortal...

On February 3, 2002, the Pope spoke to the people gathered at St. Peter's Square that science recognizes that the embryo is an individual human being:

In particular, in the study of the human embryo, science has now demonstrated that it is a human individual who possesses his own identity from the moment of fertilization.

The Pope also told the Pontifical Academy of Life on February 27, 2002 that people not yet born are human persons who must be given their legal rights:

The distinction, sometimes proposed in some international documents, between "human being" and "human person," [and] to then recognize the right to life and physical integrity only for people already born, is an artificial distinction with no scientific or philosophical foundation.

Note that the Pope used the words "science has demonstrated..." The Church takes her cue from science, and then interprets our duties accordingly.

We await the day when Christ at the Last Judgment will turn to us and say: "Come, o blessed of my Father, inherit the kingdom prepared for you from the foundation of the world. For I was an unborn child, and you cared for me."

The author: Father Anthony Zimmerman STD first came to Japan in 1948. He received his Doctorate in Sacred Theology at Catholic University in 1956, He is a retired professor of Moral Thelogy, Nanzan University, Nagoya. For further pursuit of the above subject, see the web sites: and .