Bioethics and Public Policy
Fullam, Lisa, O'Neill, William R., Theological Studies
TWO RECENT MAGISTERIAL TEXTS set the stage for our reflections: the instruction, "Dignitas personae on Certain Bioethical Questions" issued by the Congregation for the Doctrine of the Faith (CDF) on June 20, 2008; and Pope Benedict XVI's encyclical, Caritas in veritate, promulgated on June 29, 2009. (1) Pope Benedict insists that bioethical issues fall under the purview of the Church's social teaching on human rights. However, as Maura Ryan has recently argued, we have only "begun to see the implications of a human rights focus for bioethics." (2) In Part I, we consider two bioethical issues notable for generating debate on public policy: stem cell research and questions concerning HIV/AIDS. In Part II, we explore what Benedict calls the "strong links between life and ethics and social ethics" for public policy in religiously pluralist polities. (3)
Stem Cell Research
Dignitas personae is an update of the 1987 instruction Donum vitae. (4) The Instruction takes up beginning-of-life questions including fertility treatments, embryo adoption, stem cell research, preimplantation genetic diagnosis, gene therapy, and cloning; it concludes by considering the use of cells derived by destruction of human embryos.
The key to the particular applications offered in the second half of the instruction is found in the first half--in the section entitled "Anthropological, Theological, and Ethical Aspects of Human Life and Procreation": "The body of a human being, from the very first stages of its existence, can never be reduced merely to a clump of cells. The embryonic human body develops progressively according to a well-defined program with its proper finality, as is apparent in the birth of every baby." (5)
While Donum vitae stopped short of declaring the embryo to be a human person, Dignitas personae stops only a hairsbreadth from doing so. It reiterates that Donum vitae "did not define the embryo as a person," (6) and concurs with Donum vitae that science gives "a valuable indication for discerning by the use of reason a personal presence at the moment of the first appearance of a human life." (7) Moreover, "the reality of the human being for the entire span of life ... does not allow us to posit either a change in nature or a gradation in moral value, since it [the embryo] possesses full anthropological and ethical status. The human embryo has, therefore, from the very beginning, the dignity proper to a person." (8) Accordingly, Dignitas personae rejects arguments that offer individuation (the point in development after which neither twinning nor combination of two embryos into one is possible) or later stages as possible points at which full personal dignity may be imputed to the embryo: "The introduction of discrimination with regard to human dignity based on biological, psychological, or educational development, or based on health-related criteria, must be excluded." (9)
To meet Dignitas personae's moral standards, then, stem cells must be derived using technologies that: (1) do not harm extant embryos, and (2) do not inadvertently create embryos en route to producing stem cells. In laboratory language, the latter goal is to avoid totipotency while achieving pluripotency. A totipotent cell is capable of producing all the tissues of an adult, as well as the extraembryonic tissues produced by embryos--amnion, placenta, etc. A pluripotent cell can become any of the cell types of the adult organism. The instruction does not define the traits of what it calls a "true" embryo. In recent years, several technologies have been offered to derive stem cells without destroying embryos. Since the moral question hinges in part on the specifics of the technical intervention, some notes on such technologies are apropos.
In 2007, Somatic Cell Nuclear Transfer (SCNT) was achieved in primates. (10) In this process, the nucleus of an adult cell is inserted into an oocyte and induced to differentiate into various tissue types, all genetically identical to the donor cell. (11) But a clone, therapeutic or reproductive, is essentially an embryo; thus to use it for stem cells violates the first criterion, that of not harming extant embryos. Dignitas personae rules out therapeutic cloning on grounds that it amounts to sacrificing "a human life for therapeutic ends." (12)
Other technologies raise the philosophically trickier question: What counts as an embryo and on what grounds? Dignitas personae mentions three technologies as ethically uncertain at present but reaffirms that, if the technologies produce "true" human embryos, "the mere probability that a human person is involved would suffice to justify an absolutely clear prohibition of any intervention aimed at killing a human embryo." (13) The three technologies are parthenogenesis, altered nuclear transfer, and oocyte-assisted reprogramming.
Parthenogenesis is the process by which embryos are made by stimulating an unfertilized ovum to divide as though it were fertilized. (14) Are the stem cell precursors meaningfully identical to an embryo? While parthenogenetic mice have been grown to adulthood, (15) it remains unknown whether human parthenotes can develop fully. If they cannot, then they would lack the "proper finality" that Dignitas personae characterizes as a "true" embryo and thus would be acceptable for research. Not all species are identical in how they respond to laboratory manipulations of this kind. To determine definitively whether human parthenotes are capable of further development--whether they are "true" embryos or not--would likely require the kind of study that would be disallowed by Dignitas personae's criteria.
The genetic and epigenetic determinants of organismal organization are the key to understanding Altered Nuclear Transfer (ANT) and its variant, Oocyte Assisted Reprogramming (OAR). The fundamental idea is that what is definitive of a "true" embryo is not merely the complement of human DNA, but the shifting pattern of its expression--which genes are functioning when, and how those genes' products affect the developing whole. The embryo is defined not only materially but also in terms of its dynamic function, in keeping with the insights of systems biology. ANT, first proposed by Stanford's William Hurlbut, proceeds much like SCNT, with one modification: the DNA of the cell introduced into the oocyte to produce stem cells is altered before transfer, so that a gene or genes crucial to the ordered development of the embryo are "switched off' and do not function. The resulting cells "are biologically (and therefore morally) equivalent not to embryos, but to teratomas [a kind of tumor] and other fragmentary and unorganized growths." (16)
OAR proceeds by "switching on" a gene or genes in the somatic donor cell nucleus that are expressed in pluripotent cells, but are "off" in totipotent cells. The procedure produces pluripotent cells that are not derived from totipotent cells, so they can never be said to have had the "finality" present in the very early embryo; that is, they have never had the potential to produce all the necessary tissues in the coordinated fashion definitive of embryos. Thus the stage of totipotency is leapfrogged in order to go directly to the pluripotent stage. (17)
Most basically, as Hurlbut explains, ANT/OAR is a technological approach that avoids a political or moral impasse. "In contrast to developmentally or circumstantially based criteria, the ANT proposal rests on clear biologically based criteria for moral standing." (18) Critics of ANT/ OAR raise several questions, including:
(1) Does this procedure create tissues, or does it create embryos with lethal mutations? Some critics argue that the alteration in ANT is not significant enough to distinguish the procedure morally from SCNT. They ask whether, instead of creating a nonembryonic entity, ANT creates a human entity that is doomed to biological failure. (19) Usually objections of this sort implicitly or explicitly challenge systems biology itself in favor of a simpler DNA essentialism. (20)
(2) Can biological criteria establish moral standing? The 1975 CDF Declaration on Procured Abortion said that biological criteria alone cannot establish personhood; Dignitas personae says only that science makes it possible to discern a "personal presence," but the instruction stops short of a declaration of biological criteria for moral standing.
(3) If biological criteria can establish moral standing, what criteria count and why? Proponents of ANT/OAR offer an account of what it is about the early embryo that constitutes that "personal presence" by asking, "What do we mean by organism, and what degree of organization and intrinsic potential for development are the defining qualities of an embryo?" (21) The argument seems circular: if at conception the embryo is due the respect of a person, then a good description of the essential qualities of the embryo from conception will suffice as criteria for what counts as personhood. Yet how do we judge the adequacy of a description of the essential qualities of an embryo?
In 2007, a new technology that many regarded as the solution to the need for embryo-destructive research was introduced. Induced Pluripotent Stem cells (iPS cells) (22) were created by reprogramming adult skin cells to behave like stem cells; they differentiated into neuronal, cardiac, and other cell types. In 2009, normal mice were cloned from iPS cells, (23) demonstrating their complete pluripotency. A further benefit of this research is that, unlike SCNT and the other technologies used for producing stem cells, no human oocytes were needed. (24) Does this settle the embryo wars? Perhaps, but questions remain:
(1) Are iPS cells as useful as Embryonic Stem Cells (ESC)? The extent to …
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Publication information: Article title: Bioethics and Public Policy. Contributors: Fullam, Lisa - Author, O'Neill, William R. - Author. Journal title: Theological Studies. Volume: 71. Issue: 1 Publication date: March 2010. Page number: 168+. © 2009 Theological Studies, Inc. COPYRIGHT 2010 Gale Group.
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