What are the facts about fetal 'personhood'?

Dianne N. Irving
Assistant Professor, Philosophy/Bioethics
Department of Philosophy
DeSales School of Theology
Washington, D.C. 20017
Copyright Nov. 1992)
Edited for clarity and format, July 21, 2004
Reproduced with Permission

[Presented to the Men's Club, Annunciation Catholic Church, Washington, D.C., November 1992.]


Thank you all very much for being here today! It is a real pleasure to meet Monsignor Montgomery and you the parishioners of Annunciation. I am sure many of you would much rather be out in this great Fall weather doing more exciting things! Hopefully, however, you will find some of my remarks a little exciting as well, and I am very anxious to share with you a few of my concerns about some very current ethical issues.

We find ourselves engulfed in one ethical dilemma after another these days - many brought on by the explosion of medical technology. At times it seems that the "theory" has not had time to catch up with the pace of these rapid changes. We especially, as Catholics, find it difficult - and sometimes even down-right embarrassing - to seek for clarification, or even frame our responses - from our Catholic faith's perspective. We must respond. Yet how relevant can our responses possibly be, if grounded in our Catholic tradition. Doubts abound!

Such, frankly, were my anxious thoughts as well, as I prepared to attack the literature on fetal personhood for my dissertation. Just like me to pick the most controverted and explosive issue in bioethics! I wished I had time to change my topic - but it was too late! Fairly convinced that "personhood" probably started about 14 days (based on my rough survey of the arguments) I locked myself in the bathroom (to distance myself at least marginally from the teen-agers who often gathered at the Irving home) to sort out the mile-high stack of articles.

To make a long story short, I realized fairly quickly that not only was the philosophy used in these debates "a little weird" - but more disturbing to me - as a former research chemist and biologist - the science used was text-book incorrect - in virtually all of the arguments (other than those arguing for fertilization). In short, I was required to spend an extra year and a half on tracking down each scientific point and correcting it through research and myriads of conversations and meetings with other scientists at NIH and elsewhere. I resolved that once I straightened out the science, I would follow it where ever it led me! You will - as I certainly was - be shocked at where it led me!

The question of when "personhood" begins is central to all of the issues in ethics and bioethics. How one defines a human being or a human person determines what ethical choices one should make. The issues are interrelated - especially those at the beginning and the end of life - e.g., embryo and fetal research, gene screening and therapy, IVF and abortion - or the definition of brain death, the withdrawal of food and water for a patient in "PVS" (a misnomer), and euthanasia. Virtually each person sitting in this room today will be dramatically and personally touched by how we - or society at large - define a human being. Public policy is already based on it.

My talk will necessarily become a little technical - and I apologize for that. But I ask your indulgence today to at least consider seriously the information I am about to pass on to you, for these days the contemporary debates on the bioethical issues are won or lost on just these fine, seemingly esoteric scientific or philosophical points. Neither the rest of the academic community, nor we the laity in our parishes can afford to remain aloof from these issues anymore. The good news is that the position of the Church on these difficult issues is indeed based on quite solid scientific and philosophical grounds!

All too often, lately, we hear or read the lament, "We just don't or can't know what a human being or a human person really is", or, "There just is no consensus or agreement on what the definition of a human being or a human person is, so why should one person's or one group's definition be preferred over any other. The definition of a human being or of a human person cannot be objectively determined, and so must remain a relative one."

We need to and can debunk these current myths concerning the relativism of what a human being or a human person is. I want to emphasize that we can and do have an objective and empirically-based definition of a human being or human person, and that - other than conceptually, or mentally - one cannot really split a human being from a human person. "Personhood" begins when the human being begins. If ever there was an example of a time when solid reasoning and scientific facts can inform our faith this is surely one. Faith and reason, as St. Thomas notes, should not contradict, but should reinforce and complement each other. In fact, what I will have to say is not a matter of faith, or religion or even of theology - but rather is grounded in hard, cold, objective facts.

Many are arguing that the early human zygote, embryo or fetus is either not really a human being, but rather sort of like tissues or organs of the mother. Many are arguing that even if it is a human being, it is not yet a human person (and therefore deserving of the same moral and legal protections as all other human persons). Both of these kinds of arguments are blatantly incorrect and, as I will demonstrate, grounded in text-book wrong science, as well as in passé philosophies which sport a massive mind/body split (rendering them theoretically and practically indefensible).

In order to draw you into the issue as quickly as possible, I want to pose a few questions to clarify exactly what is at stake when we define a human being or a human person in one way or another. To paraphrase Aristotle: a small error in the beginning leads to a multitude of errors in the end. If our definition is incorrect - even in part - then the consequences of this incorrect definition are profound. So I pose the question - how would you yourself define a human person? Would you consider any of the following a human person: a rock; a head of cabbage; a giraffe; ...those who are old and senile in a nursing home; Alzheimer's, Parkinson's, stroke, comatose, or "PVS" patients; drunks and alcoholics; drug addicts; the homeless, poor; prisoners; the emotionally ill and depressed; mothers-in-law; teen-agers; the physically handicapped; the mentally infirm; children under 7 years of age; a new-born baby; the fetus before the mother has given birth (or, at 6 months, 8 weeks, 35 days, 14 days, 6 days, 2 days, fertilization, or the egg or the sperm). These latter examples actually constitute some of the different biological markers at which various writers claim that there is present a human person. Obviously there is some disagreement about exactly when we have, definitionally, a human person present. And that period of time between fertilization and about 8 weeks is the grayest area, i.e., the seemingly most difficult and most controversial stage.

My approach to refute "delayed personhood" will be the following. First, I will lay out in very general terms the kinds of arguments offered for the so-called "biological marker events of personhood". Second, because the science and philosophy are so intertwined, I must address briefly the correct science that we do know, and that philosophical "ball-park" which does - incredibly - realistically match that correct biology, and grounds the argument for "immediate personhood". Third, I will point out in more detail some of the major specific arguments for "delayed personhood", and indicate their use of incorrect science and philosophy. You may want to refer to the very back of this article where I have included rough charts of these issues. Hopefully this will help you at least identify and categorize the kinds of arguments you will hear, and give you some hard facts by which to reach them. It is absolutely amazing how willing many people are to "listen" to you when given simply the correct biological facts alone. When they understand them, they start putting 2+2 together on their own!


So first let me brush in broad strokes the kinds of arguments for "personhood" - or when, during embryological development we have a human being or a human person. There are three general categories of arguments: (1) "personhood" begins when the human being begins - at fertilization. There is no distinction between a human being and a human person - they cannot be split. At some definite point in time during the process of fertilization, substantial change has taken place, and a new, unique, living, individual human being who is a human person is present. Embryological development, on the other hand, is not substantial change, but only accidental change, or development. This is roughly the position of the Church - and I will go into more detail in a moment.

The second kind of argument is concerned with the actual physiological "capacity" or "precondition" required to be present if there is to be a human person. "Capacity" is meant here in a rather passive sense; that is, the focus is on whatever nature is required as a precondition for there being a human person present. This argument (like the third one) breaks down into two types of "capacities". One is the capacity to exercise so-called "rational attributes" (e.g., loving, hating, willing, reasoning, interacting with the environment around one, consciousness or self-consciousness, etc.). This is a rather "rationalistic" philosophical criterion. The other is the capacity to be "sentient", or to feel pain or pleasure. This is rather an "empiricist" or materialistic criteria. Both criteria are based on the requirement that there is a split - somehow - between a human being and a human person.

The third kind of argument is concerned with the actual exercising of these capacities. Thus some will argue that there is no person present until those "rational attributes" are actually actively operating. Others will argue there is no person present until full brain integration and full sentience is actually actively operating. What I want to stress up front is that any of the arguments from both the second and third group are biologically impossible and refutable, and that any of the arguments from the third group lead necessarily to the moral acceptance of the infanticide of perfectly normal healthy infants and children - whether one realizes this at first or not.

Thus we have this general overview of three kinds of arguments to identify: (1) those in which there is no split or distinction between a human being and a human person; (2) those which do make such a split or distinction - based on a physiological capacity as a precondition for "rationality", or "sentience", and; (3) those which also make such a split or distinction - but based on the actual active exercising of either the capacity for rationality, or for sentience. If there are any old philosophy "buffs" here in the audience, perhaps you might be beginning to see yet another "pattern" forming! (And this is why the science and the philosophy are so integrally interwined). Interestingly enough these three general categories of arguments actually tend to roughly parallel a stretch of the history of philosophy: an Aristotelean-Thomistic; a Cartesian; a rationalist or an empiricist school of thought. This leads me to my second section, i.e., the connection between the science and the philosophy.


First, although a question about "natures" seems to be fundamentally a philosophical one, any philosophical reflections, analyses or accounts about the nature of a human being or person must begin or start with the empirically observable biological facts. Otherwise our philosophical concepts actually bear little or no relation or resemblance to the real world which we are trying to understand and explain by those concepts. Instead we are left with multiple half-truths or fantasies - or wishful thinking! Only in this way can we have a realistic or objectively-based definition of a human being - one that is not relativistic.

Operationally, what is the connection between a thing's nature and the biological facts? Put briefly, the answer is that we can know what a thing is, i.e., its nature, by observing its actions or functions - how it behaves, what it does. We know that a thing acts according to the kind of thing it is, i.e., its nature. That is simply an empirically observable fact. In first-year chemistry or in microbiology students are given "unknowns" which they must identify by means of the kinds of actions or reactions exhibited by these "unknowns". Indeed, this is the obvious principle behind any basic or experimental research. The research biologist first observes the actions, reactions, functions of a biological entity and reasons from these specific kinds of actions back to the specific kind of nature it possesses. It is this nature which directs and causes such characteristic actions. As biology texts themselves discuss it: function follows form. Thus sodium burns orange, and cobalt burns blue/green - or beta-hemolytic streptococcus can only be grown on specific culture medium containing blood, but not on other media. Further, a thing is not only characterized by its nature which determines the specific kinds of actions it can do - but that same nature limits the kinds of actions it can do. That is, there are certain actions which a thing can not do because it does not have the specific kind of nature it would need to do it. For example, birds have wings and so can fly - but stones, dogs or human beings can't fly; corn stalks produce ears of corn and corn proteins and corn enzymes - but acorns, tomato plants or asteroids do not and cannot produce corn or corn proteins. Frog embryos direct the formation of frog tissues and organs - but they cannot direct the formation of human tissues and organs.

Apply these considerations to the point at hand. To determine what a human being or person is is really not all so difficult as is often claimed. We are not Gods or angels - but embodied human beings. We do have bodies - don't we? At least I have never seen a simple "soul" wandering aimlessly around the parish hall, operating a computer, car-pooling or playing soccer - without a body. In fact, I have never seen a Cartesian philosopher "thinking" without his body! As Aristotle noted, the whole man thinks; the whole man knows; and the whole man acts. There are voluminous biological facts which we do know already about the human body and its embryological development. Clearly by observing and studying these known biological facts - how the human being begins his or her biological existence as a specifically human zygote, and the kinds of specifically human functions and human actions that take place during embryological development - we can then determine to a very sophisticated extent the nature of a human being - like a human embryo - or what it is. So I will turn now to a brief consideration of the biological facts about which most if not all of us are already aware.

Before fertilizationthere exist a human sperm (containing "23" chromosomes) and a human ovum or egg (also containing "23" chromosomes - the same number, but different kinds of chromosomes). Neither the sperm nor the egg, singly, by itself, can become a human being - even if implanted in the womb of the mother. They are only gametes, cells - they are not human embryos or human beings. In contrast, the single-cell human zygote formed after fertilization contains "46" chromosomes (the number of chromosomes which is specific for members of the human species) - and these "46" chromosomes are mixed differently from the "46" chromosomes as found in the mother or in the father - that is, they are unique for that human individual. This is why an embryo or fetus is not just a tissue or organ of the mother! Thus with fertilization substantial change has taken place, i.e., a change in natures. And if allowed to "do his or her own thing", so to speak, this human zygote will biologically develop continuously without any biological gaps throughout the embryonic, fetal, neo-natal, childhood and adulthood stages - until the death of the organism. And with the advent of in vitro fertilization techniques, we can see that the early human embryo can develop in vitro on his or her own without the nutrition or protection of the mother for quite a while - someday, perhaps, even until "birth"!

I want to reiterate that a human gamete is not a human being or a human person. The number of chromosomes is only 23; it only acts or functions biologically as an egg or as a sperm, e.g., it only makes egg or sperm enzymes and proteins, etc., not specifically human enzymes and proteins; and by itself it does not have the actual capacity or potency yet to develop into a human embryo, fetus, child, or adult. And in that sense gametes are only possible human beings (i.e., non-existent human beings). Only after the sperm and the egg chromosomes combine properly and completely do we have a human being.

After fertilization there is not substantial change, but only accidental change. That is, the nature of the human being does not change, only its accidents change. Thus embryological development does not entail substantial change, but only accidental change. Once it is a human being it stays a human being, and acts and functions biologically as a human being from the start. The human zygote produces specifically human enzymes and proteins; he or she forms specifically human tissues and organ systems, and develops humanly continuously from the stage of a human single-cell zygote to the stage of a human adult.

This is observed empirically. A human zygote does not produce cabbage or carrot enzymes or proteins, and does not develop into a rock, an ear of corn, nor into a cat, a horse, a chicken, or a giraffe. Empirically it is observed that a human zygote produces specifically and characteristically human proteins and enzymes at fertilization - as demonstrated recently, for example, by experiments using transgenic mice - and that he or she develops continuously throughout embryological development in a specifically and characteristically human way.

In short - the biological facts demonstrate that at fertilization we have a truly human nature. It is not that he or she will become a human being - he or she already is a human being. We know that empirically. And this nature or capacity to act in a certain characteristic way is called, philosophically, a nature or a potency. A human zygote or embryo is not a possible human being; nor is he or she a potential human being; he or she is a human being.

Now, this is irrefutable empirical evidence that at fertilization there is a human being; but is there also a human person - or not? It is in this shifting from the paradigm of a human being to that of a human person where the philosophy comes into play again. Is a human being also a human person; or are they different things? Which philosophy is adequate to cope with this biological data?

With even only a cursory rummaging through the history of philosophy, there is one major "realistic" philosophical "ball-park" which would deny any essential distinction between a human being and a human person - they cannot be split or separated from each other - except perhaps only conceptually. This philosophy was part of a 2500 year old tradition which was the bath water, so to speak, that was thrown out with the Enlightenment baby! It is the philosophical ball-park, for example, of Aristotle-the-biologist. For Aristotle - as well as for others, such as Thomas Aquinas - his major metaphysical and anthropological treatises argue consistently for a human substance with no mind/body split (although there is evidence of a serious Platonic streak in his De Anima - that a-typical and historically problematic treatise of Aristotle's - followed unblushingly by Thomas, and so often quoted by contemporary scholars - as well as historians who researched for Roe v Wade). As Aristotle argues, "...'nature' has two senses - matter and form. If one considers 'nature' as the form, then it would be the shape or form (not separate except in statement) of things which have in themselves a source of motion" (emphasis added). Again, he says, ..."the physicist is concerned only with things whose forms are separable [in the mind], indeed, but do not exist apart from matter." And similarly, matter cannot exist apart from the form. For Aristotle, the human being is defined as one composite substance - the vegetative, sensitive and rational powers of the "soul" together with the human "body". The whole soul, he wrote, is homogenous, and in each part of the body as one whole composite:

In each of the bodily parts there are present all the parts of the soul, and the souls so present are homogenous with one another and with the whole; this means that the several parts of the soul are indisseverable from one another. (emphasis added)

And this means that the "soul" is not a separately existing substance in itself, nor is it found in any one particular organ, e.g., the heart or the brain. Aristotle addresses the very possibility of a "being-on-the-way", or an "intermediate human being", railing against the anthropological consequences of Plato's or Pythagoras' mind/body split when he very sarcastically retorts: "Yet how are we to believe in such things?" Although Aristotle-proper did not actually use the term "person", he clearly would have to concur that a human being is always a human person, for neither form (the whole soul) nor matter (the body) can exist on their own as two different things or independent substances.

Thomas Aquinas, to give another example, puts an even finer gloss on Aristotle's anthropology. To paraphrase Thomas: the name of "person" (and he uses that term) does not belong to the rational part of the soul alone, nor to the whole soul alone - but to the entire human substance (or, subsistens). This means that the whole soul, whole body and its act of existing (esse) constitute one personal substance entire - with no separate and troublesome independent "parts" each of which are claimed to be true and independent substances themselves. And it is worth noting that Thomas is one of the only philosophers who includes undesignated matter in his formal definitions of natural things, and of man.

For Thomas a human being is a human person, and the later characteristics which we will look at in these debates, such as "rational attributes", autonomous willing, or sentience are only consequential and secondary or accidental actions which follow upon certain powers (not "souls") which themselves follow upon the essential nature of the human being itself. That nature is defined as the single, whole, formal, material and existential human substance. As Thomas states:

...the soul must be in the whole body [and therefore not just in the brain], and in each part thereof .... for to the nature of the species belongs what the definition signifies; and in natural things, the definition does not signify the form only, but the form and the matter...so it belongs to the notion of man to be composed of soul, flesh and bones. (emphasis added)

These philosophical precisions force at least two major questions on any of the several types of Aristotlean/Thomistic frameworks. First, if it is claimed that the "rational" soul - which "organizes and directs embryological development" - is not infused until sometime up to about the third month, then what explains the specifically human organization of the human embryo and human fetus up to that point? Hasn't the work of this supposed "delayed rational soul" already been done - as empirically verified? If so, then this biological evidence of specifically human organization which we do empirically observe must be accounted for by the presence of the human soul right from the beginning. We also empirically observe specifically human functions and activities from the beginning - e.g., the production of specifically human proteins, enzymes, etc. If so, then this biological evidence of specifically human functions and activities which we do empirically observe must be accounted for by the presence of the human soul right from the beginning.

Second, for both Aristotle and Thomas the "human rational soul", or more properly, power, must include virtually the vegetative and sensitive powers, and for neither is there such a thing as a "rational soul" alone, or a even a whole soul alone as a complete substance. The whole human complex (body and soul) must be present together at once. Apart from the biological and conceptual absurdity of an "intermediate man", if there were only a "human vegetative" soul present at first, how do we explain the production of specifically human enzymes and proteins - instead of carrot or corn enzymes - from the very start? If there were only a "human vegetative and sensitive" soul present, how do we explain the production of specifically human tissue and organs - instead of only giraffe or gorilla organs and systems? If the human soul cannot be split (and must contain all three powers at once), and if specifically human enzymes, proteins, tissues, organs and structures are empirically observed - which they are - then the human rational soul must be present at the very beginning along with the human vegetative and sensitive "powers" of the human soul. And these powers must exist as a composite with the human body which it is organizing and whose functions and activities it is directing. Thus, at fertilization the "matter" is already appropriately organized as human; we empirically observe it as human and as developing humanly.

So far the scientific facts and the philosophical concepts match. At this point I want to take a closer look at the biological facts after fertilization, i.e., those of human embryological growth and development. Along the way I will point out several other different biological "marker events" of personhood which have been argued by others. All of these writers will make a distinction between a human being and a human person - supposedly based on these biological marker events. The use of certain biological data which they will use to support their arguments will also be addressed.

Next Page: IV. Specific examples of incorrect arguments for .........
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