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HOME :: CHAPTER 2 :: WHEN DOES HUMAN LIFE BEGIN? :: SUMMARY |
Summary
When Does Human Life Begin?
This is a note that may generate some discussion and debate. It was occasioned by a bulletin board set up by a political action group at our college. The board claimed that while philosophy and religion may have different opinions concerning when life begins, science has no such problems. Students were told that biologists were unanimous in agreeing that life starts at fertilization, and that there was no dispute in the scientific literature. Besides being a parody of science (i.e., that scientific facts are the objective truth and that all scientists agree about what these facts mean), it is wrong. I have read a wide range of scientific positions on when life begins, and these positions depend on what aspect of life one privileges in such discussions. Here is my classification scheme concerning when human life begins. You may have others.
- The metabolic view: There is no one point when life begins. The sperm cell and egg cell are as alive as any other organism.
- The genetic view: A new individual is created at fertilization. This is when the genes from the two parents combine to form an individual with unique properties.
- The embryological view: In humans, identical twinning can occur as late as day 12 pc. Such twinning produces two individuals with different lives. Even conjoined ("Siamese") twins can have different personalities. Thus, a single individuality is not fixed earlier than day 12. (In religious terms, the two individuals have different souls). Some medical texts consider the stages before this time as "pre-embryonic." This view is expressed by scientists such as Renfree (1982) and Grobstein (1988) and has been endorsed theologically by Ford (1988), Shannon and Wolter (1990), and McCormick (1991), among others. (Such a view would allow contraception, "morning-after" pills, and contragestational agents, but not abortion after two weeks.)
- The neurological view: Our society has defined death as the loss of the cerebral EEG (electroencephalogram) pattern. Conversely, some scientists have thought that the acquisition of the human EEG (at about 27 weeks) should be defined as when a human life begins. This view has been put forth most concretely by Morowitz and Trefil (1992). (This view and the ones following would allow mid-trimester abortions).
- The ecological/technological view: This view sees human life as beginning when it can exist separately from its maternal biological environment. The natural limit of viability occurs when the lungs mature, but technological advances can now enable a premature infant to survive at about 25 weeks gestation. (This is the view currently operating in many states. Once a fetus can be potentially independent, it cannot be aborted.)
- The immunological view: This view sees human life as beginning when the organism recognizes the distinction between self and non-self. In humans, this occurs around the time of birth.
- The integrated physiological view: This view sees human life as beginning when an individual has become independent of the mother and has its own functioning circulatory system, alimentary system, and respiratory system. This is the traditional birthday when the baby is born into the world and the umbilical cord is cut.
Literature Cited
Ford, N. M. 1988. When Did I Begin? Conception of the Human Individual in History. Cambridge University Press, NY.
Grobstein, C. 1988. Science and the Unborn: Choosing Human Futures. Basic Books, NY.
McCormick, R. 1991. Who or what is a pre-embryo? Kennedy Inst. Bioethics J. 1: 1-15.
Morowitz, H. J. and Trefil, J. S. 1992. The Facts of Life: Science and the Abortion Controversy. Oxford University Press, New York.
Renfree, M. B. 1982. Implantation and placentation. In Austin, C. R. and Short, R. V. (eds.) Reproduction in Mammals 2. Embryonic and Fetal Development (Second edition). Cambridge University Press, Cambridge. pp. 26-69.
Shannon, T. A. and Wolter, A. B. 1990. Reflections on the moral status of the pre-embryo. Theol. Stud. 51: 603-626.
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HOME :: CHAPTER 2 :: WHEN DOES HUMAN LIFE BEGIN? :: SUMMARY |