The question as to when a human person begins is a philosophical question--not a scientific question. I will not go into great detail here,39 but "personhood" begins when the human being begins--at fertilization. But since many of the current popular "personhood" claims in bioethics are also based on mythological science, it would be useful to just look very briefly at these philosophical (or sometimes, theological) arguments simply for scientific accuracy as well.
Philosophically, virtually any claim for so-called "delayed personhood"--that is, "personhood" does not start until some point after fertilization--involves the theoretical disaster of accepting that the idea or concept of a mind/body split has any correlate in or reflects the real world. Historically this problem was simply the consequence of wrong-headed thinking about reality, and was/is totally indefensible. It was abandoned with great embarrassment after Plato's time (even by Plato himself in his Parmenides!), but unfortunately resurfaces from time to time, e.g., as with Descartes in his Meditations, and now again with contemporary bioethics.40 And as in the question of when a human being begins, if the science used to ground these philosophical "personhood" arguments is incorrect, the conclusions of these arguments (which are based on that incorrect science) are also incorrect and invalid.
Myth 12: "Maybe a human being begins at fertilization, but a human person does not begin until after 14-days, when twinning cannot take place."
Fact 12: The particular argument in Myth 12 is also made by McCormick and Grobstein (and their numerous followers). It is based on their biological claim that the "pre-embryo" is not a developmental individual, and therefore not a person, until after 14 days when twinning can no longer take place. However, it has already been scientifically demonstrated here that there is no such thing as a "pre-embryo," and that in fact the embryo begins as a "developmental individual" at fertilization. Furthermore, twinning can take place after 14 days. Thus simply on the level of science, the philosophical claim of "personhood" advanced by these bioethicists is invalid and indefensible.
Myth 13: "A human person begins with "brain birth," the formation of the primitive nerve net, or the formation of the cortex--all physiological structures necessary to support thinking and feeling."
Fact 13: Such claims are all pure mental speculation, the product of imposing philosophical (or theological) concepts on the scientific data, and have no scientific evidence to back them up. As the well-known neurological researcher D. Gareth Jones has succinctly put it, the parallelism between "brain death" and "brain birth" is scientifically 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 asks what neurological reasons there might be 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.41
Myth 14: "A "person" is defined in terms of the active exercising of "rational attributes" (e.g., thinking, willing, choosing, self-consciousness, relating to the world around one, etc.), and/or the active exercising of "sentience" (e.g., the feeling of pain and pleasure)."
Fact 14: Again, these are philosophical terms or concepts, which have been illegitimately imposed on the scientific data. The scientific fact is that the brain, which is supposed to be the physiological support for both "rational attributes" and "sentience," is not actually completely developed until young adulthood. Quoting Moore:
"Although it is customary to divide human development into prenatal (before birth) and postnatal (after birth) periods, birth is merely a dramatic event during development resulting in a change in environment. Development does not stop at birth. Important changes, in addition to growth, occur after birth (e.g., development of teeth and female breasts). The brain triples in weight between birth and 16 years; most developmental changes are completed by the age of 25."42 (Emphasis added.)
One should also consider simply the logical--and very real--consequences if a "person" is defined only in terms of the actual exercising of "rational attributes" or of "sentience." What would this mean for the following list of adult human beings with diminished "rational attributes": e.g., the mentally ill, the mentally retarded, the depressed elderly, Alzheimer's and Parkinson's patients, drug addicts, alcoholics--and for those with diminished "sentience," e.g., the comatose, patients in a "vegetative state," paraplegics, and other paralyzed and disabled patients, diabetics or other patients with nerve or brain damage, etc.? Would they then be considered as only human beings but not also as human persons? Would that mean that they would not have the same ethical and legal rights and protections as those adult human beings who are considered as persons? Is there really such a "split" between a human being and a human person? In fact, this is the position of bioethics writers such as the Australian animal rights philosopher Peter Singer,43 the recently appointed Director of the Center for Human Values at Princeton University. Singer argues that the higher primates, e.g., dogs, pigs, apes, monkeys, are persons--but that some human beings, e.g., even normal human infants, and disabled human adults, are not persons. Fellow bioethicist Norman Fost actually considers "cognitively impaired" adult human beings as "brain dead." Philosopher/bioethicist R.G. Frey has also published that many of the adult human beings on the above list are not "persons," and suggests that they be substituted for the higher primates who are "persons" in purely destructive experimental research.44 The list goes on.
Ideas do have concrete consequences--not only in one's personal life, but also in the formulation of public policies. And once a definition is accepted in one public policy, the logical extensions of it can then be applied, invalidly, in many other policies, even if they are not dealing with the same exact issue--as happens frequently in bioethics. Thus, the definitions of "human being" and of "person" that have been concretized in the abortion debates have been transferred to several other areas, e.g., human embryo research, cloning, stem cell research, the formation of chimeras, the use of abortifacients--even to the issues of brain death, brain birth, organ transplantation, the removal of food and hydration, and research with the mentally ill or the disabled. But both private choices and public policies should incorporate sound and accurate science whenever possible. What I have tried to indicate is that in these current discussions, individual choices and public policies have been based on "scientific" myth, rather than on objective scientific facts.
5. Ronan O'Rahilly and Fabiola Müller, Human Embryology & Teratology (New York: Wiley-Liss, 1994). See also, Bruce M. Carlson, Human Embryology and Developmental Biology (St. Louis, MO: Mosby, 1994), and Keith L. Moore and T.V.N. Persaud, The Developing Human (Philadelphia: W.B. Saunders Company, 1998). [Back]
8. Note: The number of chromosomes in the definitive oocyte are not halved unless and until it is penetrated by a sperm, which really does not take place before fertilization but is in fact concurrent with and the beginning of the process of fertilization. However, for simplicity's sake, many writers (myself among them) will sometimes assume the reader clearly understands this timing, and simply say, "before fertilization the sperm and the oocyte each contain 23 chromosomes." [Back]
11. E.g., as determined in extensive numbers of transgenic mice experiments as in Kollias et al., "The human beta-globulin gene contains a downstream developmental specific enhancer," Nucleic Acids Research 15(14) (July, 1987), 5739-47; also similar work by, e.g., R.K. Humphries, A. Schnieke. [Back]
12. Holtzer et al., "Induction-dependent and lineage-dependent models for cell-diversification are mutually exclusive," Progress in Clinical Biological Research 175:3-11 (1985); also similar work by, e.g., F. Mavilio, C. Hart. [Back]
18. Ethics Advisory Board, 1979, Report and Conclusions: HEW Support of Research Involving Human In Vitro Fertilization and Embryo Transfer, Washington, D.C.: United States Department of Health, Education and Welfare, p. 101. [Back]
21. Dame Mary Warnock, Report of the Committee of Inquiry into Human Fertilization and Embryology (London: Her Majesty's Stationary Office, 1984), pp. 27, 63. See also the writings of, e.g., H. Tristram Engelhardt, John Robertson (in legal writings), R.M. Hare, Bedate and Cefalo, William Wallace. [Back]
23. National Institutes of Health: Report of the Human Embryo Research Panel, September 27, 1994 (National Institutes of Health, Division of Science Policy Analysis and Development, Bethesda, MD). [Back]
24. Clifford Grobstein, "The early development of human embryos," Journal of Medicine and Philosophy 1985:10:213-236; and Richard McCormick, "Who or what is the preembryo?" Kennedy Institute of Ethics Journal 1991:1:1-15. [Back]
33. For extensive comments on the make-up of the NIH Human Embryo Research Panel and on its Report, see several of my articles in my book, co-authored with human embryologist C. Ward Kischer, The Human Development Hoax: Time to Tell The Truth! (Clinton Township, MI: Gold Leaf Press, 1995) (1st ed.); (2nd. ed. published by authors 1997; distributed by the American Life League, Stafford, VA). [Back]
39. The use of massive historically incorrect and theoretically indefensible philosophy in the "delayed personhood" arguments has been addressed in my doctoral dissertation, A Philosophical and Scientific Analysis of the Nature of the Early Human Embryo (Washington, D.C.: Georgetown University, Department of Philosophy, 1991); see also several of my previously published articles in my book, co-authored by C. Ward Kischer, supra, note 33, The Human Development Hoax: Time To Tell The Truth!, which gives extensive references pro and con these bioethics arguments. [Back]
40. For an excellent and easy to read analysis of the problem of a mind/body split as one of the fundamental theoretical problems in contemporary bioethics theory, see Gilbert C. Meilaender, Body, Soul, and Bioethics (Notre Dame, IN: University of Notre Dame Press, 1995); see also many of the excellent articles about this problem in bioethics theory in Raanan Gillon (ed.), Principles of Health Care Ethics (New York: John Wiley & Sons, 1994); also Edwin R. DuBose, Ronald P. Hamel and Laurence J. O"Connell (eds.), A Matter of Principles? Ferment in U.S. Bioethics (Valley Forge, PA: Trinity Press International, 1994)--especially the "Preface" by Albert Jonsen. Even Daniel Callahan has admitted that the bioethics principles don't work, in "Bioethics: Private choice and common good," in The Hastings Center Report (May/June 1994), pp. 28-31. [Back]
43. Peter Singer, "Taking life: Abortion," in Practical Ethics (London: Cambridge University Press, 1981), p. 118; Helga Kuhse and Peter Singer, "For sometimes letting--and helping--die," Law, Medicine and Health Care, 1986, 3:4:149-153; Kuhse and Singer, Should the Baby Live? The Problem of Handicapped Infants (Oxford: Oxford University Press, 1985), p. 138; Singer and Kuhse, "The ethics of embryo research," Law, Medicine and Health Care, 1987, 14:13-14; Michael Tooley, "Abortion and infanticide," in Marshall Cohen (ed.) et al., The Rights and Wrongs of Abortions, (New Jersey: Princeton University Press, 1974), pp. 59, 64; H. Tristram Engelhardt, The Foundations of Bioethics (New York: Oxford University Press, 1986), p. 111. [Back]
44. R.G. Frey, "The ethics of the search for benefits: Animal experimentation in medicine," in Raanan Gillon (ed.), Principles of Health Care Ethics (New York: John Wiley & Sons, 1994), pp. 1067-1075. [Back]