What are the facts about fetal 'personhood'?


As noted above, the newly formed single-cell human zygote consists of "46" chromosomes and extra-nuclear DNA (e.g., in mitochondria) in which are coded the specific directions for virtually all of the processes of embryological development. The content of this initial pool of genetic information never changes throughout embryological development. But - to give an example of the second kind of argument (which stresses the actual physiological "capacity" or "precondition" required to be present if there is to be a human "person") - it has been argued that not all of the "information" needed is present in this single original cell, that some of the information comes from "positional molecules" in later stages of development, and some even comes from molecules originating from the mother. They conclude that the original human zygote does not contain all of the "information" needed to be a self-directing, human individual, and therefore it is neither a human being nor a human person.

This biological data is incorrect. First, "molecular information" or "positional information" is simply not the same as genetic information (i.e., what the fertilization argument is talking about). Also, molecular or positional information is itself coded in the original single-cell human zygote. As the well-known embryologist Moore discusses at great length, the genetic information in the original human zygote itself determines what molecules will be formed, which in turn determine what proteins and enzymes will be formed, which in turn determine which tissues and organs will be formed. In genetics this is called the "cascading effect". That is, the information in the original single-cell human zygote "cascades" throughout embryological development - each previous direction causing the specific formation of each succeeding direction. Thus, all "positional" or "molecular" information or direction is already determined itself by the information which preceded it, and ultimately by the original genetic information in the single-cell human zygote.

Second, although the genetic information in the human zygote may direct the absorption of molecules from the mother - that hardly means that the maternal molecules, or the mother herself, determines the very nature of the growing embryo or fetus which she is nurturing. The physical part of the nature of the embryo or fetus, we know, is determinable and set by the formal biological genetic make-up of the zygote from which he or she continuously develops - and the directing of this absorption or use of maternal molecules is done by the genetic information within the embryo or fetus - not by the mother. Those are simply the correct biological facts. As Jerome Lejeune, the internationally renowned human geneticist has testified:

...each of us has a unique beginning, the moment of conception... As soon as the twenty-three chromosomes carried by the sperm encounter the twenty-three chromosomes carried by the ovum, the whole information necessary and sufficient to spell out all the characteristics of the new being is gathered... (emphasis added)

Next, it is argued by some that this original single cell divides neatly first into 2 cells, then into 4 cells, then into 8 cells, etc. This biological data too is incorrect, (and has consequences in understanding the argument about "totipotency"). As known and published in embryological textbooks for over 60 years the original single cell divides into 2 cells - and then only one of those cells divides, giving 3 cells. After a time the other cell divides, making it 4 cells, and then each of those cells divides asynchronously, etc.

Part of what happens at this three-cell stage is that one can observe empirically the process of methylation. This observation is important philosophically. Many argue that these very early cells - including the original single-cell zygote up to the 8-cell stage - are "totipotent" (which is true). They explain totipotent cells as the most vaguely directed and least differentiated cells in all of embryological development. Each cell is not yet determined enough to be classified as an individual human being or a part of an individual human being. These cells, they say, have not yet "made up their minds" what they want to be. They can become any number of things. These cells are not differentiated or specialized enough yet.

This portrayal of totipotency, differentiation and specialization is conceptually confusing, incorrect and backwards, as Lejeune notes. Totipotent cells are the most determined and most specialized cells in all of development because they are the least differentiated. Progressively the developing cells lose, in fact, the ability to use this information. No information is lost - only the ability to use it is lost. To take an extreme example, a kidney cell contains virtually all of the information that was in the original single-cell human zygote. The kidney cell has not lost any of this information - only the ability to use this information. This ability to use or not use the information that is present results in differentiation. Differentiation is partially determined by the process of methylation (which itself is coded in the original single-cell zygote). Through methylation and other processes during embryogenesis, genes are turned on or turned off. When the cell wants to control the use of cellular information, it methylates a molecule to "silence" that gene, to block or stop its use at a certain point in development.

Thus to be so differentiated as a kidney cell is actually a negative in such arguments. The kidney cell cannot direct anything but a small miniscule part of the development of the human embryo or fetus; whereas the original totipotent human zygote contains and can use all of the information only partially used by the later cells. Thus there is nothing vague, undirected or undecided about being totipotent. Totipotent cells are supposed to be undifferentiated because they are so "all-specialized". Totipotency is suppose to happen - it is a normal part of human embryogenesis, and is indeed encoded in the original genetic information of the human zygote, as is differentiation. Differentiation, then, really represents the restricted ability to make any "decisions" - a characteristic which totipotent cells do not want.

Next, others argue for the presence of the "rational human nature" at the 2-cell stage, with the completion of the first division and the completion of the genetic input. "The two-cell stage already is, like the adult, a moment in the execution of the program 'man'". It is argued that the two-cell stage is already the same living being as the human adult arising from it. However -- we already know that the genetic input is complete at the zygote stage, and that the zygote in fact is the source of the genetic input of the two-cell stage. We also know that the zygote, too, is the same living being as both the two-cell stage and the adult stage. Thus their argument actually argues for the single-cell zygote rather than for his two-cell stage!

But to continue, the cells will proceed to divide until about 5 or 6 days, when two cell layers are formed - the trophoblast or outer cell layer, and the blastocyst or inner cell layer. As another example of the need for "human rational ensoulment", some writers have stated that this stage is significant because they can demonstrate empirically that there can be no true human individual present at this time - we have only a genetic individual, not a developmental individual. Only a "developmental individual" can be a person. These early cells, they claim, are only "collections" of undifferentiated, "totipotent" cells, and they name them, or designate them collectively, as only comprising a "pre-embryo" (a term, by the way, which is not used by embryologists - only philosophers, theologians and bioethicists). However, empirically we know that it is "okay" for these cells to be totipotent!

Additional scientific facts which they give to support these claims are the following. They claim that only the cells from the inner layer, the blastocyst, eventually become the adult human being. The cells from the trophoblast layer, they write, are all discarded after birth as the sac and the umbilical cord, etc. Thus, developmentally, the implication is, that we are not dealing only with those important cells which will become the adult human being, i.e., the blastocyst, but rather a mixture of "essential" and "non-essential" cells, i.e., a PRE-embryo. A pre-embryo, then, is not even a human embryo, much less a human person, yet.

But, again, these scientific "facts" are incorrect, and necessarily lead to incorrect philosophical concepts. It simply is not true that all of the cells from the trophoblast layer are discarded after birth. As can be found in virtually all embryology texts, many of the cells from this trophoblast layer become an integral and essential part of the constitution of the fetus, newborn and adult human being. For example, the cells from the trophoblast layer known as the yolk sac cells become part of the adult gut. And cells known as the allantois cells become part of the adult ligaments, blood cells and urinary bladder.

Thus, if the former "scientific" facts are incorrect - so also are their philosophical conclusions about "pre-embryos" and "developmental individuals" which are grounded on those incorrect scientific facts.

But the same writers continue. It is impossible, they claim, for a human person to be present until at least the 14-day marker event, at which point the primitive streak forms in the embryo. The philosophical significance of this marker, it is claimed, is that until the formation of the primitive streak it is possible for twinning to take place. The totipotent cells "do not yet know whether to be one or two individuals". After 14-days, they claim, twinning is not possible, and thus the organism is finally, "developmentally" one individual (a precondition for "ensoulment").

But, again, this science is incorrect. As Karen Dawson and others point out in these debates - and as is found in every human genetics textbook - it is possible for monozygotic twinning to take place after 14 days and the formation of the primitive streak. For example, fetus-in-fetu twins can be formed up to 2 and 3 months after fertilization, and Siamese twins even later. Also, it is known that "twinning" is sometimes genetically determined and coded in the original human single-cell zygote (as, indeed, is totipotency and differentiation). There is nothing magical, it turns out, about this 14-day stage as far as the concept of individuality and personhood is concerned. If a 2-cell, 8-cell, implantation stage, 14-day primitive streak stage embryo or 4 month fetus splits into twins, that simply means that the original entity was one individual - and now there are simply two individuals. The fact of twinning says nothing about the individuality of the first individual.

Others also argue for the 14-day stage, based primarily on the same science as above. Although they claim there is an individual present at fertilization - it is only a biological individual. Rational ensoulment cannot take place until after 14 days, at which point there is an ontological individual, i.e., when differentiation is completed and thus a distinct individuality. But aside from the problems with the above incorrect science, complete differentiation does not actually take place until well after birth. As the human embryologist Moore explains:

Human development is a continuous process that begins when an ovum from a female is fertilized by a sperm from a male. Growth and differentiation transform the zygote, a single cell formed by the union of the ovum and the sperm, into a multicellular adult human being. Most developmental changes occur during the embryonic and the fetal periods, but important [developmental] changes also occur during the other periods of development: childhood, adolescence, and adulthood... Although it is customary to divide development into prenatal and postnatal periods, it is important to realize that birth is merely a dramatic event during development resulting in a distinct change in environment. Development does not stop at birth: important developmental changes, in addition to growth, occur after birth... Most develop mental changes are completed by the age of 25.

Certainly a 14-day embryo is definitely not completely differentiated!

Sometimes other writers also argue for 14-days, based on what they call a scholastic "Aristotelean-Thomistic" theory of "natural law" - which is, in fact, turns out to be a non-sequitor! This "natural law theory" incorrectly grounds an analogy between so-called transient natures (or seeds, or beings-on-the-way), and stable natures, applying this incorrect analogy to actual human embryological development. This "transition" from plant, animal to human substances during human embryological development is actually - they claim - a series of substantial changes within human embryogenesis itself. Once again, it is based on much of the above "pre-embryo" science, as well as a very scholastic rendition of Aristotle and Aquinas. But as pointed out before, empirically and biologically there simply is no such thing as a series of substantial changes during human embryogenesis. All we have to do is look at the chromosomes during each of these supposed "substantial stages", and note that there are always "46" chromosomes present continuously from fertilization to all of the later stages of development. So how, I ask, are we to believe in such things?!

Other writers argue for 14 days because the formation of the primitive streak signals the beginning of "sentience" (the ability to feel pain and pleasure). However, we know that true sentience is not complete until well after birth.

Another example of the second kind of argument - where the focus is either the capacity for "rational attributes", or for "sentience" - is about 8 weeks or several time-markers after that - although there are many others with equally troubling science invoked. Personhood does not begin until the dawning of or the maturation of the physical substrate of human consciousness, self-consciousness, or sentience - i.e., the formation of the nervous system and/or the brain. But the fact is that complete physiological brain integration is not complete until many months or years after birth, just as the complete exercising of "rational attributes" is not possible until years after birth.

Yet there is already a movement by some in legal jurisprudence to formalize the legal concept of "brain birth" to denote that point in time biologically when there is present a "person", as a parallel to the already legal criteria of brain death. Criticisms of these claims come, for example, from Gareth Jones, a neurologist, who rejects the arguments that we can determine the biological point of either "rational attributes" or "sentience". As he states, the parallelism between brain death and brain birth is invalid. Brain death is the gradual or rapid cessation of the functions of a brain. Brain birth is the very gradual acquisition of the functions of a developing neural system. This developing neural system is not a brain. He questions, in fact, the entire assumption and retorts that there are no physiological neurological reasons for concluding that an incapacity for consciousness becomes a capacity for consciousness once this point is passed! Jones continues that the alleged symmetry is not as strong as is sometimes assumed, and that it has yet to be provided with a firm biological base!

Examples of the third category of arguments include claims that personhood requires the actual exercising of the capacity for "rational attributes" and "sentience". When the focus is "rational attributes", a "person" is defined necessarily as a young child or adult, and infanticide is openly acknowledged. For example, writers such as Peter Singer (yes, the founder of the animal rights movement) argues in the literature for infanticide of even a normal healthy infant! If, he argues, a normal new-born baby can not act rationally (as described above), then it is not a subject but only an object - and we can therefore use it in destructive experimental research if we rational agents so choose. In Singer's own words:

Now it must be admitted that these arguments apply to the newborn baby as much as to the fetus. A week-old baby is not a rational and self-conscious being, and there are many non-human animals whose rationality, self-consciousness, awareness, capacity to feel pain (sentience), and so on, exceed that of a human baby a week, a month, or even a year old. If the fetus does not have the same claim to life as a person, [then] it appears that the newborn baby is of less value than the life of a pig, a dog, or a chimpanzee. (emphasis added)

And finally, the focus on sentience or whole brain integration in this third category of arguments leads necessarily to the same conclusion, because full sentience or full brain integration does not take place until well after birth.


I could continue, biologically, down any number of "marker events" where it is argued at different points during biological development that until that point there is only a human being and only after that point there is a human person. But virtually every single marker event claimed is also using extremely erroneous scientific "data" to back up their philosophical claims of personhood. It would seem that there is more of a problem here than simply the use of problematic science. Perhaps there is also involved - whether consciously or not - the imposition on that science of certain characteristically problematic philosophical presuppositions.

What I see is the use of specific metaphysical and anthropological presuppositions which result in a classic mind/body split. A rough consideration of just how other philosophical schools of thought have defined a "human being" or a "human person", then, might be helpful. Especially in light of the obvious biological continuity present throughout the entire course of human embryological development, as well as the specifically human development which we know empirically takes place, how adequately do the other philosophical definitions of a human person reflect or match the correct biological facts as we empirically know them?

I will focus on the definition that is most generally agreed upon these days, i.e., one that is basically "derived" from Descartes or Locke. Generally, a human person is someone who is actually acting at the time in a rational manner. That is, he or she is self-conscious, self-aware, competent, autonomous, logical, mature, conversant, and interacts with the environment and other rational beings around him or her. In short, if one is acting rationally, then one is a person. If this is true, then 99% of the possible examples of human persons I gave you at the beginning of this discussion are - by definition - not persons, and therefore not deserving of moral or legal protections!

And would you agree that the killing of normal healthy human newborns is morally justifiable? If not, then we have to question, at least, such very rationalistic definitions of a human person -- and the metaphysical and epistemological foundations on which they are grounded. If one agrees with the rationalistic premise that a "human person" is defined only in terms of active "reason", then you must agree with Singer's and others' arguments for infanticide. Furthermore, any Cartesian or rationalist definition of a human being as composed of two independently existing substances (as Descartes argues, e.g., in his Meditations) collapses, since there is absolutely no interaction possible between the physical substrate (e.g., the brain) and the Mind or Reason.

On the other hand, sometimes a "human person" is defined only in terms of the whole soul - i.e., the vegetative, sensitive and rational "souls" all together. Once this whole soul unites with a body, we then have a human person. It doesn't matter, they say, whether this person is presently acting rationally. What is important is that the rational capacity is present. But if we think about it, we run into similar problems as mentioned earlier. If there are no vegetative, sensitive, or rational directions injected until about 3 months - how did a specifically human biochemical, tissue, organ system get built before 3 months?

Or perhaps we should restrict ourselves to a purely material definition of a "human person". The human person is simply a complex system of molecules, tissues and organs. But this definition has continuously failed in explaining our experience of thoughts, ideas, and concepts, and especially of intentionality, willing, or choosing. It is argued that a "person" is simply a more advanced sophisticated phase of a material complex human being. But aren't we really talking then about a secondary or accidental quality? Surely the definition of the nature of a human person should not be put in terms of only a secondary or accidental phase - however sophisticated it may be. And again, if you are arguing from the materialist premise that a "human person" is defined only in terms of "sentience", or the physical integration or functioning of the brain, then you too will have to argue for infanticide, because as pointed out, full integration and sentience is not completed until several years after birth - indeed, until the age of 25.


Given the scientific and philosophical problems inherent in the positions which argue for the various biological marker events of "personhood", can we really accept their conclusions? Are they reconcilable with and match the correct biological facts? Can you really have a human person without simultaneously having a human being? And vice-versa, can you really have a human being without also simultaneously having a human person?

I would argue no - you really can't split them (except conceptually), as rationalistic or empiricist philosophers are wont to do. And delayed hominization simply does not match up with the correct empirical facts. The definition of a "human being" or a "human person" does not have to be relative - as long as the correct science is employed, and our philosophical definitions actually match that reality. I leave it up to you to decide which of the proffered definitions make that match.

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