H U M A N G E N E T H E R A P Y 1:411-418 (1990) Mary A n n Liebert, Inc., Publishers
D o e s H u m a n G e n e Therapy R a i s e N e w Ethical Questions?
CAROL A. TAUER
ABSTRACT Consideration ofthe ethics of h u m a n gene therapy does not seem to raise questions that have never been asked before. However, particularly w h e n gene therapy is extended to modification of the germ cells, several ethical issues take on an added importance or significance. These issues are: (i) possible moral limitations on tampering with " h u m a n nature"; (ii) the extent of our responsibility to future generations; (iii) the appropriate use of early h u m a n embryos in genetic research. Furthermore, standard norms in clinical and research ethics require careful application to trials of h u m a n gene therapy, even if only somatic rather than germ-line improvements are sought.
OVERVIEW S U M M A R Y Many discussions on the ethics of human gene therapy come around to the query: Does gene therapy raise any fundamentally n e w ethical questions? Tauer attempts to answer this concern by suggesting that even though totally n e w ethical questions are not raised, several issues, which she discusses, take on added importance.
INTRODUCTION Many discussions of the ethics of human gene therapy conclude with the observation that the issues raised are not unique to this new clinical procedure. These issues seem to arise out of standard concerns in either medical or research ethics—concerns that have been amply addressed in journals and conferences and by advisory and regulatory bodies. Yet there is often an uneasiness on the part of those w h o make this observation. A m o n g scientists, ethicists, and the general public, there seems to be an intuitive sense that the modification of human genetic material takes us to a new level in clinical medicine, and therefore there must be some new ethical questions, even if w e have not yet recognized them.
Professor of Philosophy, The College of Saint Catherine, St. Paul, M N 55105. 411
TAUER What constitutes a new ethical question? A n ethical question m a y be regarded as "new" for any one of at least three reasons: 1. It has never been asked or formulated before. 2. Although it has been asked, it has been discussed as a theoretical question which until n o w did not have direct practical application. 3. The question has been applied to certain existing contexts, but n o w there are "new" applications which were formerly not possible in practice. The line between categories 2 and 3 often cannot be sharply drawn. Also, the "new" applications in category 3 m a y be so significant that they raise truly n e w challenges in relation to old questions; or these applications m a y simply provide a variation or expansion of previously examined contexts. Although the latter type of application does not really raise "new" ethical questions, its implications still deserve scrutiny, and will be considered in the final section of this paper. Recognizing new ethical questions Ethical questions that have never been asked or formulated before, i.e., those in category 1, m a y plausibly arise out ofthe techniques of h u m a n gene therapy and genetic engineering. Commentators seem to be correct, however, in noting that no really novel questions have been identified so far. This phenomenon is not unexpected; the history of science suggests that major advances in science often create intellectual discontinuities that go unrecognized or are resisted for some time. A s members of a given culture, w e are accustomed to thinking within accepted scientific and ethical paradigms. Thus, w e generally view issues within the frameworks set by these paradigms, and w e raise questions that fit received conceptual schemes. A s T h o m a s K u h n has shown in his classic work on scientific revolutions and paradigm shifts, the process of adjusting to the modes of thought required by true scientific breakthroughs ("revolutions") is a slow one, to which even scientists are resistant. "Until the scientist has learned to see nature in a different way," the truly n e w questions m a y not even be recognized/l) Genetic engineering in all its aspects and ramifications has the potential for enabling us to see nature and ourselves in a n e w way. For "powerful technologies do not just change what h u m a n beings can do, they change the very w a y w e think."(2) Thus, one might foresee that advances in genetic therapy will eventually lead us to think about ethical issues in a new way. At that time, w e m a y be able to ask n e w ethical questions. But just as the "mind-body" problem could not have been discussed before Descartes' ground-breaking work, so w e currently seem to lack the language and concepts to raise truly n e w questions with regard to genetic therapy. There are, however, ethical questions that have been discussed theoretically and are nowgoing to have their first trial in practice. In addition, there are ethical questions that find a n e w and significant application in the field of genetic engineering. Three of these questions will be discussed in the following sections.
LIMITATIONS ON TAMPERING WITH "HUMAN NATURE" Human genetic therapies give rise to two concerns, which in some sense are opposite to each other. The first arises from the belief that our ability to modify genetic structures goes to the very heart of what it is to be human. In one version of this view, the genetic code or "program" is directly given by G o d and has an intrinsic "specialness" that not only makes each h u m a n being unique, but also defines "human nature" as G o d intended it to be. In a secular version of this view, the genetic code is regarded as a "given" that w e would be ill-advised to tamper with, since w e would be modifying what it is to be "human." Once w e begin tampering, our "humanness" m a y gradually slip away from us. 412
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While this viewpoint focuses on human genetic material as unique and almost sacred, the corr viewpoint bases its concern on the similarity of h u m a n genetic material to the genetic material that directs the development of all living things. In this second view, h u m a n genetic engineering essentially reduces the h u m a n being to the material that it shares with nonhuman organisms; the equivalence of D N A between a h u m a n being and a nonhuman primate m a y be as high as 9 7 % . This similarity allows gene transfer between organisms of different species and could have the result of blurring species lines, including the line between h u m a n and nonhuman animals. These two viewpoints base their concern about genetic engineering on contrasting conceptual commitm e n t s — o n e stressing the uniqueness of h u m a n genetic material, the other its similarity to the D N A constituting all living organisms.(3) But the ethical question they raise is basically the same: H o w can w e protect what is distinctively h u m a n despite manipulations of h u m a n genetic material and the h u m a n gene pool? It would be scientifically and philosophically incorrect to claim that our humanness is defined by our genes. D N A itself does not contain or prescribe h u m a n nature, any more than atoms or molecules do. While certain genetic structures m a y be a necessary condition for humanness, they are by no means a sufficient condition. For example, h u m a n society and culture are essential elements in the development of h u m a n beings. Since societies and cultures change, as well as differ from each other, certain elements in the concept of humanness are variable, and there is no generally agreed upon definition of what "humanness" requires. At an international conference of moral philosophers and theologians held on M a y 26-28, 1990, various conceivable genetic modifications of h u m a n nature were proposed, with a view to determining the boundaries of "humanness." Even with respect to purely biological characteristics, for example, h u m a n sexual differentiation, sexual procreation and reproduction, and intrauterine gestation, there was disagreement as to whether these qualities or capacities were essential to our being human. S o m e participants maintained that they were not, and in fact, that the descendants of h u m a n beings would be h u m a n beings regardless of such modifications.(4) Rather than attempting to determine the boundaries of humanness, however, it is more important ethically to determine what w e consider desirable boundaries. W h a t modifications do w e not want to see? W h a t kind of people (to modify Jonathan Glover's title(5)) do w e not want to be? Conversations on these questions should include the general public as well as scientists and ethicists. Such conversations would take seriously the concerns of those w h o fear genetic modifications, and w h o worry that they m a y not be handled in a wise or responsible way.
O U R RESPONSIBILITIES T O F U T U R E G E N E R A T I O N S Human germ-line therapy would produce changes in human genetic material that would be intended to be passed on to future generations, hence to have a permanent effect on future individuals and on the h u m a n gene pool. Since no attempts have as yet been m a d e to do germ-line therapy in humans, w e do not k n o w h o w successful the intergenerational transmission would be. Animal experiments currently have a low rate of success, but do demonstrate that transmission can be achieved. Thus, the theoretical question of our responsibility to future generations in terms of our changing their genetic constitution has an application that is currently only a remote possibility. But the general ethical question, h o w do w e define and analyze our responsibility to future generations, is one that has largely been neglected in most ethical theories. While the literature on this topic is increasing, the discussion is only in its nascent stages.(6) A well-developed body of ethical thought is needed to deal with the applications that will arise in germ-line genetic engineering. Contributions from ethical theory This section will suggest h o w several standard ethical theories might handle our responsibility or obligation to future generations, and will review authors w h o have commented on this topic. 413
TAUER Natural law theory is based on a conception of human nature that assumes it to be relatively stable. In this theory, humanness is defined in terms of certain stable and essential qualities, which are conducive to the natural good ofthe species. W e not only have a natural tendency to protect and preserve these qualities, but our obligation to seek the good requires us to do so. Thus, natural law theory appears to entail the obligation to preserve essential h u m a n qualities, and neither to undermine them nor exchange them for others. However, this theory could accept genetic modification of properties which are regarded as "accidental" to humanness, if there is adequate justification. Surely a genetic disease or disability, which prevents the full realization of humanness, would be not merely "accidental," but an actual obstacle to full h u m a n life, and ought to be removed if possible. Furthermore, there should be no objection to germ-line therapy if a clear line can be drawn between disease and other types of genetic characteristics. According to natural law theory, our obligation to future generations would appear to consist in insuring that they are the kind of beings they ought to be—"real" and full humans. Utilitarian theory encounters substantial difficulties in considering future generations. If each person is to count equally in the utilitarian calculus, h o w do w e count all of these possible persons? D o those w h o are nearer to us in time (say, the next generation or two) get to count more heavily because w e are more certain about their existence, interests, needs, etc.? In a "preference-based" utilitarianism, h o w do w e have any notion what preferences those w h o are n o w merely possible persons will have? (Jonathan Glover suggests that the people w h o exist a thousand years from n o w m a y have a preference for re-engineered bodies.(8)) The philosopher Hans Jonas raises a standard objection to utilitarianism in this context, noting that w h e n w e m a k e environmental or genetic changes, "the predictive knowledge falls behind the technical knowledge."(9) A s chaos theory demonstrates, a small change m a d e today m a y result in enormous divergences millenia from now.(10) Even Jonas must become somewhat utilitarian in his thinking: H e acknowledges that it can no longer be responsible to say, "Let justice be done, and m a y the world perish"—precisely because it might!iU) Daniel Callahan dismisses the notion that w e have no idea what genetic constitution future generations will prefer/12) H e believes they will have desires and ideals similar to our o w n — w i l l to life, intelligence, relationships, ordered societies. In his view, great dissimilarities m a y be conceived of abstractly, but not truly imagined. The qualities he lists, apart from will to life (health, physical integrity), are broad and multifactorial, however, and not liable to modification by genetic manipulation in the foreseeable future. S o agreement on these qualities m a y provide minimal utilitarian guidance for scientific programs. Another approach to ethics, Kantian theory, faces equally serious challenges in applying its principles to future generations. Persons can be treated as ends only w h e n they actually exist; there is no intrinsic value in a merely possible person. Whether nonexistent beings can haverightsis a thorny matter. It is conceivable that beings on their w a y to personhood (e.g., fetuses) m a y haverightsthat derive from their future personhood; but it seems incoherent to define suchrightsfor merely possible persons. Since obligations to future generations cannot be defined in relation to identifiable individuals, a theory like Kantianism, which puts autonomous individuals at its center, does not appear very helpful. In his important essay on obligations to future generations, Martin Golding attempts to develop an analysis of rights which can be applied to future generations.(13) H e is correct in distinguishing having claims from making claims, and as those w h o m a y have claims (though unable to m a k e them), future generations could haverights.However, his exposition of the basis for theserightsdepends on our having a concept of the good life which w e wish to secure for future generations. Here he seems to have slid into a utilitarian m o d e of thinking, with "the good life" based on the present generation's preferences rather than on those of future generations. If future generations haverightsaccording to Golding's argument, they are very weak as claims. John Rawls, in his monumental work, The Theory of Justice, has presented a version of Kantianism that gives explicit attention to future generations.(14) Rawls' theory is a social contract theory, where all parties to the contract devise and consent to the principles for a just society. T o give fair consideration to the claims of all people, Rawls suggests a thought experiment: All persons of all generations participate in formulating the 414
ETHICAL QUESTIONS IN H U M A N GENE THERAPY principles of justice, but no person knows when, where, or how he or she will actually exist. This device for achieving impartiality certainly gives equal consideration to future as well as present generations. However, in its practical explication, it exhibits some bias in favor of the present generation, since w e must rely on a currently existing knowledge base to develop applications ofthe principles. Most current discussions of our responsibility to future generations focus on environmental issues rather than those related to h u m a n genetic engineering.(15) This focus is easily explained in that the environmental problems are already upon us, and in some respects have reached crisis proportions. Issues of h u m a n germ-line modification are still at the theoretical stage, but it is not too early to m a k e conscious efforts to relate ethical discussions about future generations to the prospects for germ-line genetic therapy.
GENETIC RESEARCH A N D EARLY H U M A N E M B R Y O S Germ-line genetic engineering is possible only if genetic modifications are introduced into human germ cells or gametes. T w o approaches are possible: Since sperm production is continuous in the male from puberty on, genetic modification affecting sperm cells could occur in the mature male. If a genetic alteration could be targeted to the Sertoli cells, which are responsible for sperm formation, then sperm cells could feasibly be modified. However, efficiency in targeting specific cells for genetic alteration has m a d e only slow progress.(16) T h e second approach, which currently is more feasible scientifically, is the genetic modification of embryonic cells before differentiation occurs. In this case, the genetic modification will be present in all cells of the developing embryo and fetus, including the germ cells. Thus, the genetic modification could be transmitted to future generations. Although this approach to germ-line genetic modification is more advanced scientifically, it is ethically and politically more controversial because it requires the manipulation of early h u m a n embryos. T h e technique of in vitro fertilization n o w makes h u m a n embryos available within the laboratory setting, thus providing the experimental material for genetic screening and modification. Since 1978, the date ofthe first in vitro fertilization resulting in term birth, all nations that have facilities for this technique have been embroiled in ethical and public policy controversies regarding its appropriate applications. T h e basic question is whether early embryos (often called "preembryos") m a y be utilized for genetic or other scientific research, rather than simply being implanted in a woman's uterus to continue their prenatal development. Great Britain recently took two steps toward furthering this type of genetic research, one scientific and one legal. In the April 19, 1990, issue of Nature,(17) British scientists reported successful screening of preimplantation embryos for sex, in cases where the parents were carriers of sex-linked genetic diseases. Female embryos were identified through cell biopsy and "Y-specific D N A amplification" w h e n the embryos were at the six-to eight-cell stage, and two w o m e n were confirmed to be carrying female twins. Given that sex has actually been identified in early embryos, undoubtedly similar biopsies and testing will soon be carried out to discern specific genetic diseases for which other embryos are k n o w n to be at risk. T h e second recent event in Great Britain is the vote on embryo research taken in the House of C o m m o n s on April 23, 1990.(18) After years of discussion and postponement of the vote, and with a close tally expected, M e m b e r s of Parliament were permitted a free conscience vote as to whether to permit h u m a n embryo research up to 14 days after fertilization. T h e House voted in favor of permitting this research, by a large margin of 364-193.(19) West Germany, on the other hand, appears to be placing strong barriers against such research. (There is speculation that this opposition arises at least partially from fear of eugenic applications, related to World W a r II recollections.(20)) T h e G e r m a n Enquete Commission, which submitted a report on germ-line gene therapy to the Bundestag ofthe Federal Republic of Germany, was unflinching in its condemnation. It recommended that the transfer of genetic material into preimplantation embryos be strictly prohibited under all conditions, 415
TAUER and that it be a federal criminal offense if the intention was to develop the manipulated embryos into complete h u m a n individuals/20 In the United States, a moratorium on federal funding of all research related to in vitro fertilization has existed since 1975, w h e n an Ethics Advisory Board was appointed to study the matter. They approved embryo research under limited conditions, but their report was never implemented by the U.S. Department of Health and H u m a n Services.(22) Currently, some states prohibit embryo research, but in others, research m a y proceed under private auspices and funding. The moral status ofthe early embryo, in particular, its status as a research subject, is the moral question that is most immediate in relation to germ-line genetic therapy. In the early embryo, somatic therapy essentially turns out to be germ-line therapy, since this embryo is undifferentiated and totipotent. At the present time, w h e n genetic screening of embryos through biopsy is just beginning, even their screening is an experimental process. A n d w h e n screening indicates a genetic disability, the morality of disposal (discarding) versus manipulation (gene insertion or gene "therapy") is an issue. All these questions depend on assessment of the moral status of the early h u m a n embryo, or preembryo. While the Catholic Church appears to speak clearly on the status of the embryo, some of its most authoritative statements are actually rather qualified and guarded. For example, in its Declaration on Abortion (1974), the Sacred Congregation notes that "there is not a unanimous tradition [on ensoulment] and authors are as yet in disagreement." Yet despite this metaphysical uncertainty, the congregation goes on to state that "from a moral point of view [it] is certain" that one m a y not harm or destroy early h u m a n embryos.(23) A number of reputable Catholic philosophers and theologians have questioned the certainty of this position. In a 1984 essay in Theological Studies, after citing these authors, I have argued that traditional principles of Catholic moral theology do not support an absolute or certain moral conclusion regarding the h u m a n preembryo.(24) The metaphysical uncertainty about the time of ensoulment of the early h u m a n embryo produces a morally ambiguous situation, and detailed study of a Catholic tradition called "probabilism" shows that a moral difference of opinion is legitimate, so that liberty of choice or action would be permissible. At the very least, the matter is legitimately open to discussion, and deserves free and fair consideration. A m o n g boards and commissions in the United States that have recently considered the matter, the Ethics Committee of the American Fertility Society deserves particular mention.(25) Along with clarifying the concept of the preembryo,(26) the committee developed balanced positions on its moral and legal status, as well as its appropriate role in research. It concluded that the preembryo "deserves [moral and legal] respect greater than that accorded to h u m a n tissue but not the respect accorded to actual persons," and that research on preembryos could be approved if results were of great clinical importance and could not be obtained otherwise. The example of "diagnosis of abnormalities in the genome" is specifically cited as an appropriate area of research.(28) In examining the ethics of h u m a n germ-line therapy, consideration of the probable use of preembryos in genetic research is crucial. Although this issue is often avoided because it is inflammatory and polarizing, an honest discussion of the prospects for germ-line therapy requires its inclusion. It is the one issue that is immediately crucial in relation to germ-line genetic engineering, and also for genetic screening and genetic selection as they are applied to embryonic h u m a n life.
E T H I C A L Q U E S T I O N S W I T H E X P A N D E D APPLICATIONS T O G E N E T H E R A P Y A large number of ethical questions encountered in clinical or research settings arise again in relation to gene therapy. S o m e of these questions m a y have greatly expanded applications, but w e have been developing tools to handle them over a number of years. Somatic cell gene therapy for genetic diseases currently raises the standard questions related to research involving h u m a n subjects.(29) W h e n do w e have enough information from laboratory and animal studies to 416
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make human trials acceptable? Can we assess the risk/benefit ratio, and what amount of risk is allowable? H o w can an adequate informed consent be obtained, particularly when children are to be the subjects in the trials? Since m a n y of those suffering from genetic diseases are desperately ill, h o w do researchers insure that this condition is not exploited solely for the purpose of advancing knowledge? These are not n e w questions, but the first trials of gene therapy are a n e w experiment, and particular sensitivity to ethical questions is imperative. A s with other innovative procedures, for example, the artificial heart, the excitement generated by the promise of a remarkable n e w therapy could be unrealistic in its expectations. With wide publicity in the mass media, prospective patients and families as well as the general public m a y become overly optimistic in their hope of medical miracles. Clinicians and researchers m a y neglect development of other possible treatments for the diseases in question, though they m a y be equally effective and less risky, because they are more ordinary and less dramatic. [In the United States, approval of trials of gene therapy for adenosine deaminase ( A D A ) deficiency w a s appropriately questioned, and thus briefly delayed, because ofthe success ofthe drug P E G - A D A in treating this disease.(30) If this issue had been ignored, the accountability ofthe screening body could have been called into question.] S o m e writers have suggested that our increasing ability to identify and possibly "cure" genetic diseases m a y lead to stigmatization and discrimination against the disabled or potentially disabled. This would reverse what is clearly the trend today in support oftherightsof disabled persons to enter mainstream life, and thus does not seem to be an immediate danger. But constant vigilance is needed to insure that such discrimination does not become a problem. Even for those w h o are not disabled by genetic conditions, the increasing power inherent in genetic screening and genetic manipulation m a y become threatening. For the more genetic knowledge that is available, the greater the power available for control. While control by governmental bodies is often mentioned, it is more likely that this power would be exercised by employers, potential employers, and insurance companies. Issues of democratic processes, individual freedom, and privacy become, not n e w , but perhaps more crucial. Thus, m a n y previously discussed bioethical issues take on a n e w significance in relation to gene therapy and genetic screening. T h e interaction goes both ways: The bioethical wisdom w e already possess illuminates the problems of genetic engineering; but the problems arising in this n e w area of research and treatment will also illuminate the general discussion of bioethics and help us to scrutinize elements w e previously neglected.
NOTES 1. Kuhn, T.S. (1970). The Structure of Scientific Revolutions, 2nd ed. (University of Chicago Press, Chicago) p. 53. (Emphasis added.) 2. Annas, G.J. (1989). Who's afraid of the human genome? Hastings Center Report 19(4), 20. 3. Technically, a distinction should be made: The sequence of human D N A resembles that of nonhuman organisms, while its expression makes us unique. Thus, there is a gap between sequence and expression, which is also important for clinical applications of gene manipulation. 4. Unpublished proceedings, Dialogue on H u m a n Gene Therapy, Bethesda, M D , M a y 26-28, 1990. 5. Glover, J. (1984). What Sort of People Should There Be? (Penguin Books, N e w York). 6. See Partridge, E. ed. (1981). Responsibilities to Future Generations: Environmental Ethics (Prometheus Books, Buffalo, N Y ) . The journal Environmental Ethics often prints articles on aspects of our responsibility to future generations. However, the Bibliography of Bioethics, 1986, 1987, 1988, and 1989, lists no article entries under its headings, "Future Generations" and "Obligations to Future Generations." 7. For a broad overview ofthe theories discussed here, see Arras, J., and Hunt, R. (1989). Ethical theory in the medical context. InEthical Issues in Modern Medicine, 3rded. J. Arras andN. Rhoden, eds. (MayfieldPubl. Co., Mountain View, C A ) , esp. pp. 6-29. 8. Glover, op. cit., pp. 23-56. 9. Jonas H., Technology and responsibility: The ethics of an endangered future. In E. Partridge, ed., op. cit., p. 29. 417
TAUER 10. 11. 12. 13. 14. 15.
Gleick, J. (1988). Chaos: Making a New Science. (Penguin Books, New York) pp. 11-31. Jonas, op. cit., p. 30. Callahan, D., What obligations do we have to future generations? In E. Partridge, ed., op. cit., pp. 73-85. Golding, M.P., Obligations to future generations. In E. Partridge, ed., op. cit., pp. 61-72. Rawls, J. (1971). A Theory of Justice. (Harvard University Press, Cambridge) pp. 284-298. For two exceptions, see Agius, E. (1989). "Germ-line cells: Our responsibilities for future generations. In Ethics in the Natural Sciences. D. Mieth and J. Pohier, eds. (T. & T. Clark Ltd., Edinburgh) pp. 105-115; also Jones, H. Genetic endowment and obligations to future generations. In E. Partridge, ed., op. cit., pp. 247-259. 16. Personal communication from W . French Anderson, August 23, 1990. 17. Handy side, A. H. et al. (1990). Pregnancies from biopsied human preimplantation embryos sexed by Y-specific D N A amplification. Nature 344, 768-770. 18. Aldhous, P. (1990). Pressure stepped up on embryo research. Nature 344, 691; also Opinion, Embryo research. Nature 344, 690. 19. Aldhous, P. (1990). Pro-life actions backfire. Nature 345, 7. 20. Specter, M . (1990). Genetic experiment plants fear in Germans. Star Tribune (Mpls.), April 20, 1990, p. 2A. (Reprinted from the Washington Post.). 21. (1988). A Report from Germany (an extract from Prospects and Risks of Gene Technology: The Report ofthe Enquete Commission). Bioethics 2, 254-263. 22. See summary in Tauer, C A . (1990). Essential ethical considerations for public policy on assisted reproduction. In Beyond Baby M . (1989). D.M. Bartels, et al., eds. (Humana Press, Clifton, NJ) pp. 65-86; also Tauer, In vitro fertilization: Are there still ethical problems?" J. Minn. Acad. Sci. 54, 3-7. 23. Sacred Congregation for the Doctrine ofthe Faith. (1975). Declaration on Abortion. (U.S. Catholic Conference, Washington, D C ) pp. 6 and 13, n. 19. 24. Tauer, C A . (1984). The tradition of probabilism and the moral status ofthe early embryo. Theol. Stud. 45, 3-33. Reprinted in P.B. Jung and T.A. Shannon, eds. (1988). Abortion & Catholicism: The American Debate. (Crossroad, N e w York) pp. 54-84. 25. Ethics Committee of the American Fertility Society. (1986). Ethical considerations of the new reproductive technologies. Fertil. Steril. 46, no. 3, Suppl. 1. 26. "A preembryo is a product of gametic union from fertilization to the appearance of the embryonic axis. The preembryonic state is considered to last until 14 days after fertilization" (ibid., p. vii). 27. Ibid., pp. 29S-30S. 28. Ibid., pp. 56S-51S. 29. See Anderson, W.F., and Fletcher, J.C. (1980). Gene therapy in human beings: When is it ethical to begin?N. Engl. J. Med. 303, 1293-1297; Office of Technology Assessment. (1984). Human Gene Therapy: Background Paper (U.S. Congress, Office of Technology Assessment, (Washington, D C ) OTA-BP-BA-32; Anderson, W.F. (1985). Human gene therapy: Scientific and ethical considerations. J. Med. Philos. 10, 275-291; Walters, L. (1986). The ethics of human gene therapy. Nature 320, 225-227. 30. Angier, N. Gene therapy for a disease weighed by National panel. N e w York Times, March 30, 1990, p. 8; Angier, Gene treatments for human illness may be tried soon. N e w York Times, Aug. 1, 1990, pp. Al and A8.
Address reprint requests to: Dr. Carol A. Tauer Department of Philosophy The College of St. Catherine 2004 Randolph Avenue St. Paul, M N 55105 Received for publication August 17, 1990; accepted after revision October 3, 1990.
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D o e s H u m a n G e n e Therapy R a i s e N e w Ethical Questions?
CAROL A. TAUER
ABSTRACT Consideration ofthe ethics of h u m a n gene therapy does not seem to raise questions that have never been asked before. However, particularly w h e n gene therapy is extended to modification of the germ cells, several ethical issues take on an added importance or significance. These issues are: (i) possible moral limitations on tampering with " h u m a n nature"; (ii) the extent of our responsibility to future generations; (iii) the appropriate use of early h u m a n embryos in genetic research. Furthermore, standard norms in clinical and research ethics require careful application to trials of h u m a n gene therapy, even if only somatic rather than germ-line improvements are sought.
OVERVIEW S U M M A R Y Many discussions on the ethics of human gene therapy come around to the query: Does gene therapy raise any fundamentally n e w ethical questions? Tauer attempts to answer this concern by suggesting that even though totally n e w ethical questions are not raised, several issues, which she discusses, take on added importance.
INTRODUCTION Many discussions of the ethics of human gene therapy conclude with the observation that the issues raised are not unique to this new clinical procedure. These issues seem to arise out of standard concerns in either medical or research ethics—concerns that have been amply addressed in journals and conferences and by advisory and regulatory bodies. Yet there is often an uneasiness on the part of those w h o make this observation. A m o n g scientists, ethicists, and the general public, there seems to be an intuitive sense that the modification of human genetic material takes us to a new level in clinical medicine, and therefore there must be some new ethical questions, even if w e have not yet recognized them.
Professor of Philosophy, The College of Saint Catherine, St. Paul, M N 55105. 411
TAUER What constitutes a new ethical question? A n ethical question m a y be regarded as "new" for any one of at least three reasons: 1. It has never been asked or formulated before. 2. Although it has been asked, it has been discussed as a theoretical question which until n o w did not have direct practical application. 3. The question has been applied to certain existing contexts, but n o w there are "new" applications which were formerly not possible in practice. The line between categories 2 and 3 often cannot be sharply drawn. Also, the "new" applications in category 3 m a y be so significant that they raise truly n e w challenges in relation to old questions; or these applications m a y simply provide a variation or expansion of previously examined contexts. Although the latter type of application does not really raise "new" ethical questions, its implications still deserve scrutiny, and will be considered in the final section of this paper. Recognizing new ethical questions Ethical questions that have never been asked or formulated before, i.e., those in category 1, m a y plausibly arise out ofthe techniques of h u m a n gene therapy and genetic engineering. Commentators seem to be correct, however, in noting that no really novel questions have been identified so far. This phenomenon is not unexpected; the history of science suggests that major advances in science often create intellectual discontinuities that go unrecognized or are resisted for some time. A s members of a given culture, w e are accustomed to thinking within accepted scientific and ethical paradigms. Thus, w e generally view issues within the frameworks set by these paradigms, and w e raise questions that fit received conceptual schemes. A s T h o m a s K u h n has shown in his classic work on scientific revolutions and paradigm shifts, the process of adjusting to the modes of thought required by true scientific breakthroughs ("revolutions") is a slow one, to which even scientists are resistant. "Until the scientist has learned to see nature in a different way," the truly n e w questions m a y not even be recognized/l) Genetic engineering in all its aspects and ramifications has the potential for enabling us to see nature and ourselves in a n e w way. For "powerful technologies do not just change what h u m a n beings can do, they change the very w a y w e think."(2) Thus, one might foresee that advances in genetic therapy will eventually lead us to think about ethical issues in a new way. At that time, w e m a y be able to ask n e w ethical questions. But just as the "mind-body" problem could not have been discussed before Descartes' ground-breaking work, so w e currently seem to lack the language and concepts to raise truly n e w questions with regard to genetic therapy. There are, however, ethical questions that have been discussed theoretically and are nowgoing to have their first trial in practice. In addition, there are ethical questions that find a n e w and significant application in the field of genetic engineering. Three of these questions will be discussed in the following sections.
LIMITATIONS ON TAMPERING WITH "HUMAN NATURE" Human genetic therapies give rise to two concerns, which in some sense are opposite to each other. The first arises from the belief that our ability to modify genetic structures goes to the very heart of what it is to be human. In one version of this view, the genetic code or "program" is directly given by G o d and has an intrinsic "specialness" that not only makes each h u m a n being unique, but also defines "human nature" as G o d intended it to be. In a secular version of this view, the genetic code is regarded as a "given" that w e would be ill-advised to tamper with, since w e would be modifying what it is to be "human." Once w e begin tampering, our "humanness" m a y gradually slip away from us. 412
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While this viewpoint focuses on human genetic material as unique and almost sacred, the corr viewpoint bases its concern on the similarity of h u m a n genetic material to the genetic material that directs the development of all living things. In this second view, h u m a n genetic engineering essentially reduces the h u m a n being to the material that it shares with nonhuman organisms; the equivalence of D N A between a h u m a n being and a nonhuman primate m a y be as high as 9 7 % . This similarity allows gene transfer between organisms of different species and could have the result of blurring species lines, including the line between h u m a n and nonhuman animals. These two viewpoints base their concern about genetic engineering on contrasting conceptual commitm e n t s — o n e stressing the uniqueness of h u m a n genetic material, the other its similarity to the D N A constituting all living organisms.(3) But the ethical question they raise is basically the same: H o w can w e protect what is distinctively h u m a n despite manipulations of h u m a n genetic material and the h u m a n gene pool? It would be scientifically and philosophically incorrect to claim that our humanness is defined by our genes. D N A itself does not contain or prescribe h u m a n nature, any more than atoms or molecules do. While certain genetic structures m a y be a necessary condition for humanness, they are by no means a sufficient condition. For example, h u m a n society and culture are essential elements in the development of h u m a n beings. Since societies and cultures change, as well as differ from each other, certain elements in the concept of humanness are variable, and there is no generally agreed upon definition of what "humanness" requires. At an international conference of moral philosophers and theologians held on M a y 26-28, 1990, various conceivable genetic modifications of h u m a n nature were proposed, with a view to determining the boundaries of "humanness." Even with respect to purely biological characteristics, for example, h u m a n sexual differentiation, sexual procreation and reproduction, and intrauterine gestation, there was disagreement as to whether these qualities or capacities were essential to our being human. S o m e participants maintained that they were not, and in fact, that the descendants of h u m a n beings would be h u m a n beings regardless of such modifications.(4) Rather than attempting to determine the boundaries of humanness, however, it is more important ethically to determine what w e consider desirable boundaries. W h a t modifications do w e not want to see? W h a t kind of people (to modify Jonathan Glover's title(5)) do w e not want to be? Conversations on these questions should include the general public as well as scientists and ethicists. Such conversations would take seriously the concerns of those w h o fear genetic modifications, and w h o worry that they m a y not be handled in a wise or responsible way.
O U R RESPONSIBILITIES T O F U T U R E G E N E R A T I O N S Human germ-line therapy would produce changes in human genetic material that would be intended to be passed on to future generations, hence to have a permanent effect on future individuals and on the h u m a n gene pool. Since no attempts have as yet been m a d e to do germ-line therapy in humans, w e do not k n o w h o w successful the intergenerational transmission would be. Animal experiments currently have a low rate of success, but do demonstrate that transmission can be achieved. Thus, the theoretical question of our responsibility to future generations in terms of our changing their genetic constitution has an application that is currently only a remote possibility. But the general ethical question, h o w do w e define and analyze our responsibility to future generations, is one that has largely been neglected in most ethical theories. While the literature on this topic is increasing, the discussion is only in its nascent stages.(6) A well-developed body of ethical thought is needed to deal with the applications that will arise in germ-line genetic engineering. Contributions from ethical theory This section will suggest h o w several standard ethical theories might handle our responsibility or obligation to future generations, and will review authors w h o have commented on this topic. 413
TAUER Natural law theory is based on a conception of human nature that assumes it to be relatively stable. In this theory, humanness is defined in terms of certain stable and essential qualities, which are conducive to the natural good ofthe species. W e not only have a natural tendency to protect and preserve these qualities, but our obligation to seek the good requires us to do so. Thus, natural law theory appears to entail the obligation to preserve essential h u m a n qualities, and neither to undermine them nor exchange them for others. However, this theory could accept genetic modification of properties which are regarded as "accidental" to humanness, if there is adequate justification. Surely a genetic disease or disability, which prevents the full realization of humanness, would be not merely "accidental," but an actual obstacle to full h u m a n life, and ought to be removed if possible. Furthermore, there should be no objection to germ-line therapy if a clear line can be drawn between disease and other types of genetic characteristics. According to natural law theory, our obligation to future generations would appear to consist in insuring that they are the kind of beings they ought to be—"real" and full humans. Utilitarian theory encounters substantial difficulties in considering future generations. If each person is to count equally in the utilitarian calculus, h o w do w e count all of these possible persons? D o those w h o are nearer to us in time (say, the next generation or two) get to count more heavily because w e are more certain about their existence, interests, needs, etc.? In a "preference-based" utilitarianism, h o w do w e have any notion what preferences those w h o are n o w merely possible persons will have? (Jonathan Glover suggests that the people w h o exist a thousand years from n o w m a y have a preference for re-engineered bodies.(8)) The philosopher Hans Jonas raises a standard objection to utilitarianism in this context, noting that w h e n w e m a k e environmental or genetic changes, "the predictive knowledge falls behind the technical knowledge."(9) A s chaos theory demonstrates, a small change m a d e today m a y result in enormous divergences millenia from now.(10) Even Jonas must become somewhat utilitarian in his thinking: H e acknowledges that it can no longer be responsible to say, "Let justice be done, and m a y the world perish"—precisely because it might!iU) Daniel Callahan dismisses the notion that w e have no idea what genetic constitution future generations will prefer/12) H e believes they will have desires and ideals similar to our o w n — w i l l to life, intelligence, relationships, ordered societies. In his view, great dissimilarities m a y be conceived of abstractly, but not truly imagined. The qualities he lists, apart from will to life (health, physical integrity), are broad and multifactorial, however, and not liable to modification by genetic manipulation in the foreseeable future. S o agreement on these qualities m a y provide minimal utilitarian guidance for scientific programs. Another approach to ethics, Kantian theory, faces equally serious challenges in applying its principles to future generations. Persons can be treated as ends only w h e n they actually exist; there is no intrinsic value in a merely possible person. Whether nonexistent beings can haverightsis a thorny matter. It is conceivable that beings on their w a y to personhood (e.g., fetuses) m a y haverightsthat derive from their future personhood; but it seems incoherent to define suchrightsfor merely possible persons. Since obligations to future generations cannot be defined in relation to identifiable individuals, a theory like Kantianism, which puts autonomous individuals at its center, does not appear very helpful. In his important essay on obligations to future generations, Martin Golding attempts to develop an analysis of rights which can be applied to future generations.(13) H e is correct in distinguishing having claims from making claims, and as those w h o m a y have claims (though unable to m a k e them), future generations could haverights.However, his exposition of the basis for theserightsdepends on our having a concept of the good life which w e wish to secure for future generations. Here he seems to have slid into a utilitarian m o d e of thinking, with "the good life" based on the present generation's preferences rather than on those of future generations. If future generations haverightsaccording to Golding's argument, they are very weak as claims. John Rawls, in his monumental work, The Theory of Justice, has presented a version of Kantianism that gives explicit attention to future generations.(14) Rawls' theory is a social contract theory, where all parties to the contract devise and consent to the principles for a just society. T o give fair consideration to the claims of all people, Rawls suggests a thought experiment: All persons of all generations participate in formulating the 414
ETHICAL QUESTIONS IN H U M A N GENE THERAPY principles of justice, but no person knows when, where, or how he or she will actually exist. This device for achieving impartiality certainly gives equal consideration to future as well as present generations. However, in its practical explication, it exhibits some bias in favor of the present generation, since w e must rely on a currently existing knowledge base to develop applications ofthe principles. Most current discussions of our responsibility to future generations focus on environmental issues rather than those related to h u m a n genetic engineering.(15) This focus is easily explained in that the environmental problems are already upon us, and in some respects have reached crisis proportions. Issues of h u m a n germ-line modification are still at the theoretical stage, but it is not too early to m a k e conscious efforts to relate ethical discussions about future generations to the prospects for germ-line genetic therapy.
GENETIC RESEARCH A N D EARLY H U M A N E M B R Y O S Germ-line genetic engineering is possible only if genetic modifications are introduced into human germ cells or gametes. T w o approaches are possible: Since sperm production is continuous in the male from puberty on, genetic modification affecting sperm cells could occur in the mature male. If a genetic alteration could be targeted to the Sertoli cells, which are responsible for sperm formation, then sperm cells could feasibly be modified. However, efficiency in targeting specific cells for genetic alteration has m a d e only slow progress.(16) T h e second approach, which currently is more feasible scientifically, is the genetic modification of embryonic cells before differentiation occurs. In this case, the genetic modification will be present in all cells of the developing embryo and fetus, including the germ cells. Thus, the genetic modification could be transmitted to future generations. Although this approach to germ-line genetic modification is more advanced scientifically, it is ethically and politically more controversial because it requires the manipulation of early h u m a n embryos. T h e technique of in vitro fertilization n o w makes h u m a n embryos available within the laboratory setting, thus providing the experimental material for genetic screening and modification. Since 1978, the date ofthe first in vitro fertilization resulting in term birth, all nations that have facilities for this technique have been embroiled in ethical and public policy controversies regarding its appropriate applications. T h e basic question is whether early embryos (often called "preembryos") m a y be utilized for genetic or other scientific research, rather than simply being implanted in a woman's uterus to continue their prenatal development. Great Britain recently took two steps toward furthering this type of genetic research, one scientific and one legal. In the April 19, 1990, issue of Nature,(17) British scientists reported successful screening of preimplantation embryos for sex, in cases where the parents were carriers of sex-linked genetic diseases. Female embryos were identified through cell biopsy and "Y-specific D N A amplification" w h e n the embryos were at the six-to eight-cell stage, and two w o m e n were confirmed to be carrying female twins. Given that sex has actually been identified in early embryos, undoubtedly similar biopsies and testing will soon be carried out to discern specific genetic diseases for which other embryos are k n o w n to be at risk. T h e second recent event in Great Britain is the vote on embryo research taken in the House of C o m m o n s on April 23, 1990.(18) After years of discussion and postponement of the vote, and with a close tally expected, M e m b e r s of Parliament were permitted a free conscience vote as to whether to permit h u m a n embryo research up to 14 days after fertilization. T h e House voted in favor of permitting this research, by a large margin of 364-193.(19) West Germany, on the other hand, appears to be placing strong barriers against such research. (There is speculation that this opposition arises at least partially from fear of eugenic applications, related to World W a r II recollections.(20)) T h e G e r m a n Enquete Commission, which submitted a report on germ-line gene therapy to the Bundestag ofthe Federal Republic of Germany, was unflinching in its condemnation. It recommended that the transfer of genetic material into preimplantation embryos be strictly prohibited under all conditions, 415
TAUER and that it be a federal criminal offense if the intention was to develop the manipulated embryos into complete h u m a n individuals/20 In the United States, a moratorium on federal funding of all research related to in vitro fertilization has existed since 1975, w h e n an Ethics Advisory Board was appointed to study the matter. They approved embryo research under limited conditions, but their report was never implemented by the U.S. Department of Health and H u m a n Services.(22) Currently, some states prohibit embryo research, but in others, research m a y proceed under private auspices and funding. The moral status ofthe early embryo, in particular, its status as a research subject, is the moral question that is most immediate in relation to germ-line genetic therapy. In the early embryo, somatic therapy essentially turns out to be germ-line therapy, since this embryo is undifferentiated and totipotent. At the present time, w h e n genetic screening of embryos through biopsy is just beginning, even their screening is an experimental process. A n d w h e n screening indicates a genetic disability, the morality of disposal (discarding) versus manipulation (gene insertion or gene "therapy") is an issue. All these questions depend on assessment of the moral status of the early h u m a n embryo, or preembryo. While the Catholic Church appears to speak clearly on the status of the embryo, some of its most authoritative statements are actually rather qualified and guarded. For example, in its Declaration on Abortion (1974), the Sacred Congregation notes that "there is not a unanimous tradition [on ensoulment] and authors are as yet in disagreement." Yet despite this metaphysical uncertainty, the congregation goes on to state that "from a moral point of view [it] is certain" that one m a y not harm or destroy early h u m a n embryos.(23) A number of reputable Catholic philosophers and theologians have questioned the certainty of this position. In a 1984 essay in Theological Studies, after citing these authors, I have argued that traditional principles of Catholic moral theology do not support an absolute or certain moral conclusion regarding the h u m a n preembryo.(24) The metaphysical uncertainty about the time of ensoulment of the early h u m a n embryo produces a morally ambiguous situation, and detailed study of a Catholic tradition called "probabilism" shows that a moral difference of opinion is legitimate, so that liberty of choice or action would be permissible. At the very least, the matter is legitimately open to discussion, and deserves free and fair consideration. A m o n g boards and commissions in the United States that have recently considered the matter, the Ethics Committee of the American Fertility Society deserves particular mention.(25) Along with clarifying the concept of the preembryo,(26) the committee developed balanced positions on its moral and legal status, as well as its appropriate role in research. It concluded that the preembryo "deserves [moral and legal] respect greater than that accorded to h u m a n tissue but not the respect accorded to actual persons," and that research on preembryos could be approved if results were of great clinical importance and could not be obtained otherwise. The example of "diagnosis of abnormalities in the genome" is specifically cited as an appropriate area of research.(28) In examining the ethics of h u m a n germ-line therapy, consideration of the probable use of preembryos in genetic research is crucial. Although this issue is often avoided because it is inflammatory and polarizing, an honest discussion of the prospects for germ-line therapy requires its inclusion. It is the one issue that is immediately crucial in relation to germ-line genetic engineering, and also for genetic screening and genetic selection as they are applied to embryonic h u m a n life.
E T H I C A L Q U E S T I O N S W I T H E X P A N D E D APPLICATIONS T O G E N E T H E R A P Y A large number of ethical questions encountered in clinical or research settings arise again in relation to gene therapy. S o m e of these questions m a y have greatly expanded applications, but w e have been developing tools to handle them over a number of years. Somatic cell gene therapy for genetic diseases currently raises the standard questions related to research involving h u m a n subjects.(29) W h e n do w e have enough information from laboratory and animal studies to 416
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make human trials acceptable? Can we assess the risk/benefit ratio, and what amount of risk is allowable? H o w can an adequate informed consent be obtained, particularly when children are to be the subjects in the trials? Since m a n y of those suffering from genetic diseases are desperately ill, h o w do researchers insure that this condition is not exploited solely for the purpose of advancing knowledge? These are not n e w questions, but the first trials of gene therapy are a n e w experiment, and particular sensitivity to ethical questions is imperative. A s with other innovative procedures, for example, the artificial heart, the excitement generated by the promise of a remarkable n e w therapy could be unrealistic in its expectations. With wide publicity in the mass media, prospective patients and families as well as the general public m a y become overly optimistic in their hope of medical miracles. Clinicians and researchers m a y neglect development of other possible treatments for the diseases in question, though they m a y be equally effective and less risky, because they are more ordinary and less dramatic. [In the United States, approval of trials of gene therapy for adenosine deaminase ( A D A ) deficiency w a s appropriately questioned, and thus briefly delayed, because ofthe success ofthe drug P E G - A D A in treating this disease.(30) If this issue had been ignored, the accountability ofthe screening body could have been called into question.] S o m e writers have suggested that our increasing ability to identify and possibly "cure" genetic diseases m a y lead to stigmatization and discrimination against the disabled or potentially disabled. This would reverse what is clearly the trend today in support oftherightsof disabled persons to enter mainstream life, and thus does not seem to be an immediate danger. But constant vigilance is needed to insure that such discrimination does not become a problem. Even for those w h o are not disabled by genetic conditions, the increasing power inherent in genetic screening and genetic manipulation m a y become threatening. For the more genetic knowledge that is available, the greater the power available for control. While control by governmental bodies is often mentioned, it is more likely that this power would be exercised by employers, potential employers, and insurance companies. Issues of democratic processes, individual freedom, and privacy become, not n e w , but perhaps more crucial. Thus, m a n y previously discussed bioethical issues take on a n e w significance in relation to gene therapy and genetic screening. T h e interaction goes both ways: The bioethical wisdom w e already possess illuminates the problems of genetic engineering; but the problems arising in this n e w area of research and treatment will also illuminate the general discussion of bioethics and help us to scrutinize elements w e previously neglected.
NOTES 1. Kuhn, T.S. (1970). The Structure of Scientific Revolutions, 2nd ed. (University of Chicago Press, Chicago) p. 53. (Emphasis added.) 2. Annas, G.J. (1989). Who's afraid of the human genome? Hastings Center Report 19(4), 20. 3. Technically, a distinction should be made: The sequence of human D N A resembles that of nonhuman organisms, while its expression makes us unique. Thus, there is a gap between sequence and expression, which is also important for clinical applications of gene manipulation. 4. Unpublished proceedings, Dialogue on H u m a n Gene Therapy, Bethesda, M D , M a y 26-28, 1990. 5. Glover, J. (1984). What Sort of People Should There Be? (Penguin Books, N e w York). 6. See Partridge, E. ed. (1981). Responsibilities to Future Generations: Environmental Ethics (Prometheus Books, Buffalo, N Y ) . The journal Environmental Ethics often prints articles on aspects of our responsibility to future generations. However, the Bibliography of Bioethics, 1986, 1987, 1988, and 1989, lists no article entries under its headings, "Future Generations" and "Obligations to Future Generations." 7. For a broad overview ofthe theories discussed here, see Arras, J., and Hunt, R. (1989). Ethical theory in the medical context. InEthical Issues in Modern Medicine, 3rded. J. Arras andN. Rhoden, eds. (MayfieldPubl. Co., Mountain View, C A ) , esp. pp. 6-29. 8. Glover, op. cit., pp. 23-56. 9. Jonas H., Technology and responsibility: The ethics of an endangered future. In E. Partridge, ed., op. cit., p. 29. 417
TAUER 10. 11. 12. 13. 14. 15.
Gleick, J. (1988). Chaos: Making a New Science. (Penguin Books, New York) pp. 11-31. Jonas, op. cit., p. 30. Callahan, D., What obligations do we have to future generations? In E. Partridge, ed., op. cit., pp. 73-85. Golding, M.P., Obligations to future generations. In E. Partridge, ed., op. cit., pp. 61-72. Rawls, J. (1971). A Theory of Justice. (Harvard University Press, Cambridge) pp. 284-298. For two exceptions, see Agius, E. (1989). "Germ-line cells: Our responsibilities for future generations. In Ethics in the Natural Sciences. D. Mieth and J. Pohier, eds. (T. & T. Clark Ltd., Edinburgh) pp. 105-115; also Jones, H. Genetic endowment and obligations to future generations. In E. Partridge, ed., op. cit., pp. 247-259. 16. Personal communication from W . French Anderson, August 23, 1990. 17. Handy side, A. H. et al. (1990). Pregnancies from biopsied human preimplantation embryos sexed by Y-specific D N A amplification. Nature 344, 768-770. 18. Aldhous, P. (1990). Pressure stepped up on embryo research. Nature 344, 691; also Opinion, Embryo research. Nature 344, 690. 19. Aldhous, P. (1990). Pro-life actions backfire. Nature 345, 7. 20. Specter, M . (1990). Genetic experiment plants fear in Germans. Star Tribune (Mpls.), April 20, 1990, p. 2A. (Reprinted from the Washington Post.). 21. (1988). A Report from Germany (an extract from Prospects and Risks of Gene Technology: The Report ofthe Enquete Commission). Bioethics 2, 254-263. 22. See summary in Tauer, C A . (1990). Essential ethical considerations for public policy on assisted reproduction. In Beyond Baby M . (1989). D.M. Bartels, et al., eds. (Humana Press, Clifton, NJ) pp. 65-86; also Tauer, In vitro fertilization: Are there still ethical problems?" J. Minn. Acad. Sci. 54, 3-7. 23. Sacred Congregation for the Doctrine ofthe Faith. (1975). Declaration on Abortion. (U.S. Catholic Conference, Washington, D C ) pp. 6 and 13, n. 19. 24. Tauer, C A . (1984). The tradition of probabilism and the moral status ofthe early embryo. Theol. Stud. 45, 3-33. Reprinted in P.B. Jung and T.A. Shannon, eds. (1988). Abortion & Catholicism: The American Debate. (Crossroad, N e w York) pp. 54-84. 25. Ethics Committee of the American Fertility Society. (1986). Ethical considerations of the new reproductive technologies. Fertil. Steril. 46, no. 3, Suppl. 1. 26. "A preembryo is a product of gametic union from fertilization to the appearance of the embryonic axis. The preembryonic state is considered to last until 14 days after fertilization" (ibid., p. vii). 27. Ibid., pp. 29S-30S. 28. Ibid., pp. 56S-51S. 29. See Anderson, W.F., and Fletcher, J.C. (1980). Gene therapy in human beings: When is it ethical to begin?N. Engl. J. Med. 303, 1293-1297; Office of Technology Assessment. (1984). Human Gene Therapy: Background Paper (U.S. Congress, Office of Technology Assessment, (Washington, D C ) OTA-BP-BA-32; Anderson, W.F. (1985). Human gene therapy: Scientific and ethical considerations. J. Med. Philos. 10, 275-291; Walters, L. (1986). The ethics of human gene therapy. Nature 320, 225-227. 30. Angier, N. Gene therapy for a disease weighed by National panel. N e w York Times, March 30, 1990, p. 8; Angier, Gene treatments for human illness may be tried soon. N e w York Times, Aug. 1, 1990, pp. Al and A8.
Address reprint requests to: Dr. Carol A. Tauer Department of Philosophy The College of St. Catherine 2004 Randolph Avenue St. Paul, M N 55105 Received for publication August 17, 1990; accepted after revision October 3, 1990.
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