Part 3 of the debate regarding embryonic stem cell research begins with a comment that Tom made in part 2. This part specifically addresses the question of whether an embryo is a living human being.
So your argument is that medical science should not be pursued because you see no possible benefit from the study of leftover embryos you admit do exist? Why is it preferable that any number of embryos be destroyed, rather than donated to the advancement of human biology?
I have never denied that benefits could not be gained from embryonic stem cell research. But just because a line of research can be medically beneficial does not mean that it is morally right to conduct that research. Various examples from the past can be raised, but that would be tangential to the primary point of this discussion. Most people would agree that scientific research that involves the purposeful killing of innocent human beings should not be allowed. The crux of the matter, then, is whether the embryos used in ESCr are living human beings. Tom argues that they are not, therefore no limitations need be placed on ESCr.
Can you explain why a human being without a brain or heart or blood is "alive" when it is an embryo, yet "dead" at any other stage of development?
Tom has already provided the answer in his question. The criteria used to describe being alive at a certain stage of development cannot be arbitrarily applied to all stages of development. An 18-year old who cannot do arithmetic, or read, or write in complete sentences, would rightly be described as having failed to be educated. But it would be wholly unreasonable to say that a kindergartener in her first week of class who cannot do these same things has failed to be educated. The criteria for what constitutes an educated student at one particular age aren’t necessarily the same criteria for a student at a completely different stage in her education. So a kindergartener can be considered to be a successful student even though she cannot yet read, write, or do math.
In the same way, an embryo can be alive even though it does not have the specific bodily functions or organs that characterize living newborns, teenagers, and adults.
Defining Embryonic Death
But analogy alone won’t suffice to make the point, so I will draw from Tom’s arguments from the Facebook discussion topic. So as not to misrepresent Tom’s case, I will quote directly from his comments.
Okay, so you put an IVF/ESCr embryo into a clinical setting. Respiration = 0, heart rate = 0, brain activity = 0. Declare time of death. Ovum donor donates to medical research, ESC are harvested just as any other corpse's organs would be. Embryo = DEAD HUMAN BEING by ANY clinical definition. With no uterus to gestate in, the embryo cannot become a living human being.
The cessation of brain activity is the accepted clinical indication of the death of a postnatal human being, but it is not what defines the death of a human being. The clinically agreed upon Uniform Determination of Death Act (UDDA) states that “brain death is the legal equivalent of death because . . . the capacity for life is irretrievably lost when the entire brain, including the brain stem, has ceased functioning.” First, what defines “death” is when “the capacity for life is irretrievably lost,” sometimes phrased as the “irreversible loss of integrated organic function,” which has been clinically determined to occur for postnatal human beings when brain functioning ceases. Second, the UDDA applies only to human beings who once had brain function; the definition of clinical death for an embryo must obviously depend on different criteria, since an embryo has not yet developed a central nervous system.
Landry and Zucker, et al have written the defining study (“Hypocellularity and Absence of Compaction as criteria for embryonic death”)for determining the death of a human being before the onset of neural development. In the proposal paper for this study, they wrote:
For a developed human organism, brain death marks the irreversible loss of the capacity for all ongoing and integrated organic functioning. We propose that the defining capacity of a 4- or 8-cell human embryo is continued and integrated cellular division, growth, and differentiation. We further propose that an embryo that has irreversibly lost this capacity, even as its individual cells are alive, is properly considered organismically dead. (“Embryonic death and the creation of human embryonic stem cells,” Donald W. Landry and Howard A. Zucker, The Journal of Clinical Investigation)
Landry, et al offered the three characteristics of drastically low cell count, arrest of cell division, and failure to compact by embryonic day five as indication of the irreversible loss of integrated function and therefore death of the embryo. I plan to revisit this study in greater detail at a later time, but the key point for this discussion is that there is a clear clinical distinction between a dead embryonic human being and a living embryonic human being. This distinction does not depend on whether the embryo is in utero or ex utero; in other words, an IVF embryo in the petri dish or one slated to be destroyed by a researcher for stem cells is just as much a living human being as one that has been conceived naturally, so long as it does not exhibit the three characteristics that define embryonic death. After all, the study was conducted on IVF embryos that had already been rejected as “non-viable;” however, the researchers determined that over two-thirds of these “non-viable” embryos were not organismically dead. As Landry et al wrote: “‘Nonviability’ merely indicates the lack of a capacity to develop to live birth and does not necessarily imply death.”
When Does a Human Life Begin?
Even this may be beside the point, for when Tom writes, “Embryo = DEAD HUMAN BEING” he implies that the embryo was first alive to begin with, for only living beings can die. But some of Tom’s other comments suggest that he considers the embryo was never a living human being to begin with:
People with some misguided "moral" objections can cram their self-righteous ignorances into whatever orifice they want, because within two decades, ESCr-derived treatments will be both as available and morally unambiguous as organ transplantation is today. My kidney is alive, it is human, but it is in no way a human being. An embryo is just a clump of cells, and without a woman to gestate in, that's all they can ever be. On the human level, they are dead and can never qualify as "alive" for lack of respiration, blood, or CNS. If you see no ethical quandary over the donation of organs, there can be none against ESCr.
Now I am not opposed to organ donation. In fact, I am a designated organ donor myself. What I am opposed to, however, is any form of organ donation that first requires purposefully killing a living human being in order to harvest his or her organs. So the critical question is what defines the beginning of life of a human being?
In this area the medical literature is clear:
“Human development begins at fertilization, the process during which a male gamete or sperm… unites with a female gamete or oocyte (ovum) to form a single cell called a zygote. This highly specialized, totipotent cell marked the beginning of each of us as a unique individual.”
“A zygote is the beginning of a new human being (i.e., an embryo).” (Keith L. Moore, T.V.N. Persaud, The Developing Human: Clinically Oriented Embryology, 7th edition. Philadelphia, PA: Saunders, 2003. pp. 16, 2)
“Although life is a continuous process, fertilization (which, incidentally, is not a ‘moment’) is a critical landmark because, under ordinary circumstances, a new genetically distinct human organism is formed when the chromosomes of the male and female pronuclei blend in the oocyte.” (Ronan O'Rahilly and Fabiola Müller, Human Embryology and Teratology, 3rd edition. New York: Wiley-Liss, 2001. p. 8)
“It is the penetration of the ovum by a spermatozoan and resultant mingling of the nuclear material each brings to the union that constitues the culmination of the process of fertilization and marks the initiation of the life of a new individual.” (Clark Edward Corliss, Patten's Human Embryology: Elements of Clinical Development. New York: McGraw Hill, 1976. p. 30)
“Almost all higher animals start their lives from a single cell, the fertilized ovum(zygote)... The time of fertilization represents the starting point in the life history, or ontogeny, of the individual.” (Carlson, Bruce M. Patten's Foundations of Embryology. 6th edition. New York: McGraw-Hill, 1996, p. 3)
In testimony before a Senate Judicial Subcommittee in 1981, these medical experts testified:
Professor Micheline Matthews-Roth, Harvard University Medical School: “It is incorrect to say that biological data cannot be decisive...It is scientifically correct to say that an individual human life begins at conception.”
Dr. Alfred M. Bongioanni, Professor of Pediatrics and Obstetrics, University of Pennsylvania: “I have learned from my earliest medical education that human life begins at the time of conception….. I submit that human life is present throughout this entire sequence from conception to adulthood and that any interruption at any point throughout this time constitutes a termination of human life....”
Dr. Jerome LeJeune, Professor of Genetics, University of Descartes: “After fertilization has taken place a new human being has come into being. [It] is no longer a matter of taste or opinion.… The human nature of the human being from conception to old age is not a metaphysical contention, it is plain experimental evidence. Each individual has a very neat beginning, at conception.”
Dr. Watson A. Bowes, University of Colorado Medical School: “The beginning of a single human life is from a biological point of view a simple and straightforward matter – the beginning is conception.”
The report concludes with the following: “Physicians, biologists, and other scientists agree that conception marks the beginning of the life of a human being - a being that is alive and is a member of the human species. There is overwhelming agreement on this point in countless medical, biological, and scientific writings.” (Report, Subcommittee on Separation of Powers to Senate Judiciary Committee S-158, 97th Congress, 1st Session 1981, 7)
The Embryo as a Developing Human Being
Finally, in response to Tom’s claim that “An embryo is just a clump of cells, and without a woman to gestate in, that's all they can ever be…” I offer this distinction by Dr. Maureen Condic, Associate Professor of Neurobiology and Anatomy at the University of Utah School of Medicine:
The critical difference between a collection of cells and a living organism is the ability of an organism to act in a coordinated manner for the continued health and maintenance of the body as a whole. It is precisely this ability that breaks down at the moment of death, however death might occur. Dead bodies may have plenty of live cells, but their cells no longer function together in a coordinated manner. We can take living organs and cells from dead people for transplant to patients without a breach of ethics precisely because corpses are no longer living human beings. Human life is defined by the ability to function as an integrated whole—not by the mere presence of living human cells….
Embryos are in full possession of the very characteristic that distinguishes a living human being from a dead one: the ability of all cells in the body to function together as an organism, with all parts acting in an integrated manner for the continued life and health of the body as a whole.
Linking human status to the nature of developing embryos is neither subjective nor open to personal opinion. Human embryos are living human beings precisely because they possess the single defining feature of human life that is lost in the moment of death—the ability to function as a coordinated organism rather than merely as a group of living human cells. (“Life: Defining the Beginning by the End,” Maureen L. Condic)
The fact that an embryo will never be implanted into a womb and given the chance to continue developing doesn’t change its identity as a human being. All living organisms are dependent on environmental factors to continue living. But the lack of these dependencies does not change the nature of the organism. A man placed in a room with no food or water does not cease to be a human being the instant he is sealed inside; unless he is released he will die within a few days, but he remains a living human being until the moment of death. In the same way, an embryo in a petri dish does not cease to be a living human being when it is not implanted into a womb; it remains a living human being until it dies from lack of sustenance or is destroyed by a researcher or technician.
An embryo is not dead, nor is it just a clump of living cells. An embryo does not become a human being at some later point or only when it is provided with a uterus to gestate in, an embryo is a living human being at a very early stage of development that has not yet developed the attributes of more mature human beings. To deny the humanity of the embryo is to deny the medical literature.