Heterogeneous assemblages of bioethics and science: the “pre-embryo” debate in America

Abstract

This paper explores the “pre-embryo” debate in America to analyze the relationship between scientific uncertainty and moral decision-making. This paper explores how an ethical debate among bioethicists around the term “pre-embryo” has been transformed into a scientific “fact” debate between developmental biology and embryology. This transformation is driven by the scientism of ethical reasoning that stresses scientific claims to increase the credibility of ethical claims. This paper concludes that the “pre-embryo” debate is not an ethical controversy over a unified science but rather credibility struggles between two heterogeneous assemblages of science and bioethics.

Keywords:

• pre-embryo
• stem cell research
• scientism
• heterogeneous assemblages
• scientific uncertainty

Introduction

The ideal situation of bioethics with the least failure is that ethical reasoning takes place after scientific debates are adequately stabilized because bioethics cannot stand on incorrect scientific facts. In the early history of bioethics, scientific uncertainty was not significant in moral decision-making because bioethics was a late response to bad medical research (e.g., the Tuskegee Syphilis case). However, with growing public attention to the ethics of biomedical research, bioethics currently engages biomedical practice much earlier. Bioethicists “rely on thought-experiments and ‘what if’ science fiction speculation some of the time” (Hedgecoe 2004, p. 133). Scientific debates, therefore, actually occur within ethical debates. Under high scientific uncertainty, the ideal situation of bioethics does not arrive. Therefore, it is of great significance to explore the relationship between scientific uncertainty and moral decision-making.

This paper explores the “pre-embryo” debate in America since the late 1970s to analyze the relationship between scientific uncertainty and moral decision-making.1 It is important to note that this paper does not address the whole of the human embryo debate but focuses on the “pre-embryo” debate, a smaller debate on the term “pre-embryo” within the human embryo debate. Therefore, this paper does not deal with a wide variety of liberal and conservative views on the moral status of human embryos, but pays attention to the emergence of personhood (i.e., developmental individuality) related to the term “pre-embryo”.2

This paper analyzes how an ethical debate among bioethicists around the term “pre-embryo” has been transformed into a scientific “fact” debate between classical embryology and developmental biology.3 I claim that the “pre-embryo” debate is not an ethical debate over a unified science but a controversy between two heterogeneous assemblages of science and bioethics: an assemblage of pro-pre-embryo (PP) bioethics and developmental biology vs. a counter assemblage of anti-pre-embryo (AP) bioethics and embryology.4 Each assemblage generates the “symbiotic relationship” between bioethics and science on each side (Evans 2006, p. 223). These heterogeneous assemblages of bioethics and science are produced by scientism of ethical reasoning that emphasizes scientific claims in order to enhance the credibility of ethical claims.5

This paper begins with a brief history of embryology and developmental biology. This historical context of embryology is very significant in understanding a tension between two scientific fields of embryology. This tension would evolve into an ethical debate among bioethicists regarding human embryo research. The second section examines heterogeneous assemblages of PP bioethics and developmental biology. The third section explores heterogeneous assemblages of AP bioethics and embryology.

A tension between embryology and developmental biology

In the first half of the twentieth century, the division between genetics and embryology became prevalent after embryologist T.H. Morgan made a “split” between the two fields (Allen 1985, Gilbert 1991, Maienschein 2003). Although believing that heredity and development are inextricably intertwined, Morgan expressed dissatisfaction about the use of genetics as an explanatory tool for embryonic development (Keller 2000, p. 76). He thought that Mendelian theories are built on “preformationism”, an idea that the form of embryo is already pre-determined in the egg or sperm, and that it is inconsistent with the “epigenesis” of embryology, an idea that the form gradually changes during development (Allen 1985, Maienschein 1985). He thought that cytoplasm controls this development. As a result, the dichotomy between genetics and embryology emerged.

Since the 1940s, some embryologists such as S. Gluecksohn-Schoenheimer, C. H. Waddington and geneticist Boris Ephrussi had tried to reconcile genetics and embryology and paved the path from embryology to developmental biology (Burian et al. 1991, Gilbert 1991, Keller 2000). With the advent of molecular biology in the 1950s, genetics and embryology become reunited through the field of developmental biology. Developmental biology started to explain that even if genes do not change during embryonic development, they are differently expressed as differentiation and development take place. According to Maienschein (2003, p. 123), in the 1960s, “the field of embryology as the study of embryos began to give way to the study of developmental biology (the study of how genetics informs differentiation and development).” Embryologists who transformed themselves into developmental biologists began to work near the center of molecular biology (Burian et al. 1991, p. 221).

The “pre-embryo” debate in this paper, however, shows that developmental biology has not yet completely healed the “split” between genetics and embryology. Embryology tried to avoid the reductionism of genetics and “has kept alive a holistic view”, an idea that “the whole is indeed greater than the sum of its parts” (Allen 1985, p. 143). Historian and philosopher of science, Evelyn Fox Keller (2000) also indicates the conceptual inadequacy of genes as causes of development, arguing instead for the significance of genetic and functional “redundancy” in development.6 Keller argues that the notion of redundancy bears some resemblance to the division between genetics and classical embryology in the first half of the twentieth century. Recognizing such tension between embryology and developmental biology, the next sections will address how, since the 1980s, this scientific tension has developed into an ethical debate between PP and AP bioethicists.

Heterogeneous assemblages of PP bioethics and developmental biology

This section presents how PP bioethics is entangled with developmental biology and the next section addresses how AP bioethics is entangled with embryology. These heterogeneous assemblages are driven by the scientism of ethical reasoning, which is one of the most powerful ways to attack counterpart bioethics and to attain the credibility of moral claims. This scientism means that both camps of bioethicists insist that their own moral claims are more scientific by arguing that their own scientific facts are value-neutral, while contending that their counterpart bioethicists' facts are value-laden. The scientism is very useful in gaining credibility in the ethical reasoning of both bioethicists, who seek peaceful alliances with scientists on each side. The scientism also transmutes the ethical debate into a scientific fact debate.

In 1979 developmental biologist Clifford Grobstein (1979) introduced the term “pre-embryo” in a Scientific American article.7 Grobstein was a mammalian developmental biologist. He was also an influential figure who became deeply involved in ethical debates on reproductive medicine in the 1970s and 1980s. In order to denote early embryos, he used various terms in this article: “preimplantation embryos”, “pre-embryos”, and “prepersons”. Grobstein (1979) explains that a pre-embryo is not able to establish singleness prior to implantation, because it has a possibility of twinning. He argues that the moral status of the pre-embryo is identical to that of cells and tissues.

Developmental biologist and former student of Clifford Grobstein Michael J. Flower (1992) has a similar view on the term “pre-embryo”. Flower (1992, p. 440) argues that the reason why the distinction between embryos and pre-embryos is significant is because of “a major transformation in the developmental nature of ICM [the inner cell mass]”: “the ICM is capable of splitting in two to yield twins, a capacity that is lost with the beginning of gastrulation”. Flower claims that the pre-embryonic stage of embryonic development means the stage up to the completion of “implantation – a process taking about a week and therefore completed by 12 to 14 days of development” (p. 440).

The use of the term pre-embryo is not unique to Grobstein and his colleagues (see Grobstein et al. 1983). Developmental biologist and historian Scott F. Gilbert et al. (2005, p. 41) also define “pre-embryo” as an embryo that “has not individualized yet” at the early end of the gestation period (roughly the first two weeks): “it is a mass of cells that can still divide to form identical twins and other multiple siblings. Moreover, there is no certainty that a ‘pre-embryo’ will develop into a fetus or new born.”

The pre-embryo's capacity of twinning became woven into a discussion on the definition of “individuality”. This individuality is very significant in determining personhood, because the US Constitution puts human rights on some entities, according to this personhood (Flower 1992). Therefore, a scientific definition of whether an embryo is capable of being a singleton or doubleton becomes an important analytic criterion to decide moral personhood. However, the concept of individuality regarding the capacity of twinning is not Grobstein's unique idea. This idea can be traced back to the early 1970s (see Hellengers 1970, pp. 4–5, Diamond 1975, p. 315).

The widespread use of “pre-embryo” resulted from Richard A. McCormick's introduction of this term in an ethical debate. McCormick was a prestigious Jesuit moral theologian at the Kennedy Institute of Ethics. Grobstein met McCormick in the Ethics Advisory Board (EAB) organized in 1978 by Department of Health, Education, and Welfare (DHEW). McCormick was an EAB member, and Grobstein provided testimony to the committee. This encounter between Grobstein and McCormick is the first sign of the emergence of a heterogeneous assemblage of developmental biology and PP bioethics.

EAB adopted a 14-day limit in its 1979 report (EAB 1979) in March 1979, three months before Grobstein articulated the term pre-embryo in a Scientific American article. A 14-day limit here is however associated with “the completion of implantation” of embryos into the uterus (EAB 1979, p. 107) and the “potential for sentience” (p. 28) rather than the notion of individuality. In 1978, Clifford Grobstein also gave testimony to this board about the potential of sentience, suggesting that “human cells, tissues and organs that have no reasonable prospect of possessing or developing sentient awareness” are “human materials rather than human beings or persons” (p. 28).

EAB (1979) concluded that “the human embryo is entitled to profound respect; but this respect does not necessarily encompass the full legal and moral rights attributed to persons” (p. 101). EAB did not use the term “pre-embryo” but “early human embryos” (p. 27) and “preimplantation embryos” (p. 29). Later, faced by pro-life members of Congress and the Reagan administration, DHEW decided not to offer federal funding for human embryo research. EAB was disbanded in 1980, resulting in a de facto “moratorium” on human embryo research until the NIH Revitalization Act of 1993 removed the barrier to this research.

The term pre-embryo was for the first time adopted by the Ethics Committee of the American Fertility Society (AFS) (currently the American Society for Reproductive Medicine) in 1986 and again in 1990. Both Grobstein and McCormick participated together on this committee. The AFS committee, in its 1986 and 1990 report, identically defines pre-embryo as follows:

The preembryo is a multicelluar aggregate without even rudimentary human form. … it is not yet established as a single individual, being able under unusual circumstances to undergo twinning to yield two or more individuals, or fusion with an another preembryo to become a composite embryo. The preembryo is therefore not yet developmentally stabilized as a single individual. … [T]he preembryo deserves respect greater than that accorded to human tissue but not the respect accorded to actual persons. (AFS 1990, pp. 34S–35S)

In 1988, based on his work on the AFS committee, Grobstein published a significant book entitled Science and the unborn. This book addresses moral and policy issues concerning the pre-embryo (Grobstein 1988, pp. 58–82). In this book, he urges us to consider the moral status of pre-embryos based on the concept of “developmental individuality” (p. 21). Grobstein (1988, p. 26) claims that “genetic individuality” (of pre-embryos) is established at fertilization, while “developmental individuality” (of embryos) arises with the appearance of the primitive streak (one of the first signs of gastrulation) from “about ten to fourteen days after fertilization”. Therefore, embryological development, Grobstein (1993, pp. 195–196) insists, takes “[its] progression from zygote to pre-embryo, to embryo, and to fetus; each a platform on which to build heightened status on the road to full personhood”. Compared to his article in 1979 that casts pre-embryos as cells and tissues, here he displays a more upgraded version that grants some moral respect to the pre-embryo (“pre-person”) (see Grobstein 1993, p. 193).

On the other hand, McCormick (1991) published his article about the pre-embryo in the first article of the Kennedy Institute of Ethics Journal. This article draws on the work of the AFS committee and Grobstein's (1988) work. In criticizing Roman Catholic thinkers who argue that an individual human life begins at the fertilization, McCormick (1991, p. 4) insists that “developmental individuality” emerges after the primitive streak appears, because twinning can occur at the zygote stage:

The moral status – and specifically the controversial issue of personhood – is related to attainment of developmental individuality (being the source of one individual). This contrasts with the view that holds that personhood occurs earlier, at the point of genetic uniqueness. I believe that an embryo that has developed to the point where it can be one individual and one individual only, differs in moral status from a preembryo that has not, even if in many cases we may choose to treat them similarly. … It should be noted that at the zygote stage the genetic individual is yet developmentally single – a source of only one individual. As we will see, that does not occur until a single body axis has begun to form, near the end of the second week post fertilization when implantation is underway. (McCormick 1991, pp. 2–3)

The pre-embryo/embryo distinction, however, was soon refuted by the Tennessee trial court of Davis v. Davis regarding one divorced couple's use of frozen embryos. The trial court concluded that frozen pre-embryos were “human beings”. In contrast to the trial court, the Tennessee Supreme Court of Appeal overruled it in 1992, when this decision was based on the AFS report and Grobstein's (1988) work (Tennessee Supreme Court 1992, pp. 593–597). In fact, there was a serious dispute about the term pre-embryos at the trial court (p. 593). French geneticist Jerome Lejeune gave his testimony that there is no distinction between embryos and pre-embryos. However, his expertise in obstetrics or gynecology (specifically in the field of infertility) and in medical ethics was questioned by the Court of Appeal. According to the Court's report:

Dr. Lejeune's opinion was disputed by Dr. Irving Ray King, the gynecologist who performed the IVF Procedures in this case. Dr. King is a medical doctor who had practiced as a sub-specialty in the arena of infertility and reproductive endocrinology for 12 years. … He testified that the currently accepted term for the zygote immediately after division is “preembryo” and that this term applies up until 14 days after fertilization. He testified that this 14-day period defines the accepted period for preembryo research. At about 14 days, he testified, the group of cells begins to differentiate in a process that permits the eventual development of the different body parts which will become an individual. … Dr. King's testimony was corroborated by the other experts who testified at trial, with the exception of Dr. Lejeune. It is further supported by the American Fertility Society, an organization of 10,000 physicians and scientists who specialize in problems of human infertility. (Tennessee Supreme Court 1992, p. 593)

The rejection of Lejeune's testimony is a consequence of what I call scientism of ethical reasoning in which moral decision-making on a pre-embryo is legitimized by science. This is another sign of a heterogeneous assemblage of PP bioethics and developmental biology. According to Lejeune (1992, pp. 147–155), three of the witnesses – Irving Ray King, Charles Alex Shivers, John A. Robertson – disagreed with Dr Lejeune's opinion at this court. Their dissenting opinions, Lejeune insists, were built on the AFS report:

Dr. King, Dr. Shivers, and Professor Roberton rely at least to some degree on the report of the Ethics Committee of The American Fertility Society in forming the basis of their opinions. Each makes a distinction between “embryo” and “pre-embryo” in conformity to the American Fertility Society guidelines. … Professor Robertson is a member of the Ethics Committee, Dr. King is a member of the American Fertility Society and various witnesses gave testimony indicating reliance on the pronouncements of the committee. (Lejeune 1992, p. 151)

At the trial court of Davis v. Davis, John Robertson, Professor of Law at the University of Texas at Austin, testified that “it is not clear” that a “pre-embryo is a unique individual” (Lejeune 1992, p. 185). Robertson was a member of the AFS's Ethics Committee with Clifford Grobstein and Richard McCormick. He served on the Committee in Fall 1985. Libertarian bioethicist Robertson (1990) uses the term “early embryo” interchangeably with “pre-embryo”, referring to Grobstein's (1988) work and the AFS report. Robertson has actually taken a more generous stance on the moral status of pre-embryo. Robertson (1991) later responded to the McCormick's (1991) article, arguing that McCormick's idea that grants some respect to pre-embryos is too “strict”.8

Together with the AFS committee, the American College of Obstetricians and Gynecologists Committee on Ethics (ACOG 1994) is another ethics committee that used the term pre-embryo in 1994. This committee mentioned Grobstein's (1988) work in its report. Ten years later, in 2004 when the Presidential Election occurred, this committee (ACOG 2004) reprinted this report. This committee defines pre-embryo as “the developing cells produced by the division of the zygote until the formation of the embryo proper at the appearance of the primitive streak about 14 days after fertilization”(ACOG 1994, p. 299, ACOG 2004, p. 99).

In recent years, stem cell scientists and bioethicists tend to use more neutral terms such as zygote, morula, primitive streak, and blastocyst in order to avoid a controversy around the term “pre-embryo”. Nonetheless, the term is still reproduced by some bioethicists. As for Jeffrey P. Spike (2002), current professor of Medical Humanities and Social Sciences of Florida State University, to create a scientific claim informed by developmental biology is one of the most powerful ways to criticize conservative bioethics and President Bush's stem cell policy. It is scientism of ethical reasoning that stresses scientific claims to enhance the credibility of moral claims. Spike insists:

Indeed many biologists in this field – embryology or developmental biology – don't call these early stages of development an embryo, but a preimplantation embryo or pre-embryo. … Philosophically, it is misleading to call pre-embryos potential humans. … [Bush] ended up proposing an ethically confused policy that could slow medical progress. (Spike 2002, pp. 45–46)

Heterogeneous assemblages of AP bioethics and embryology

Among scientists, however, there has been a serious scientific debate involving the term “pre-embryo”. As mentioned earlier, on 10 August 1989, at the trial case of Davis v. Davis, using the terms “tiny human beings” and “early human beings”, and saying that “Madame [Mary Sue Davis], the mother, wants to rescue babies from this concentration can”, French geneticist Dr Lejeune (1992) rejected the distinction between pre-embryos and embryos:

[T]his terminology [Embryo] was accepted the world over for more than fifty years by all the specialists of the world, and we had no need at all of a sub-class which would be called a preembryo, because there is nothing before the embryo. Before an embryo there is sperm and an egg, and that's it. And the sperm and an egg cannot be a preembryo because you don't know what sperm will go into what egg, but once it is made, you have got a zygote and when it divides it's an embryo and that's it. I think it's important because people would believe that a preembryo does not have the same significance as an embryo. (Lejeune 1992, p. 38)

Some embryologists have accused Grobstein of creating the term “pre-embryo” intentionally in order to tolerate the destruction of early embryos. They also insist that Grobstein is not a human embryologist but an amphibian embryologist. In fact, Grobstein is a mammalian developmental biologist. O'Rahilly and Muller (1992, p. 55) argue that “pre-embryo” included in the Normina Embryologica is “ill-defined” and “inaccurate”. Clayton Ward Kischer (2005) argues that the term “pre-embryo” was excluded by the Nomenclature Committee of the American Association of Anatomists from the Terminologia Embryologica. Kischer (1994, p. 75) argues that Grobstein's “New Wave Embryology” is “nonsense” and the term “pre-embryo” is “a pure invention”:

Many of the cells in the early cluster are destined to become part of the embryo proper. We simply don't know which ones they are. One might reasonably theorize that as mitotic divisions continue, an outer layer is distinguished from inner cells. However, it is not known whether or not this positioning is static or if, in fact, some cells change places with others. … Unfortunately, this is what Grobstein is doing by promoting this false concept of a “pre-embryo,” then lamenting; what should be done with it? As many human embryologists (as Grobstein may have supporters) will claim there is no such stage as the “pre-embryo.” The basic reason is that such artificial stages are significant only to the extant political discourse. It is no value to human development because all of development from fertilization to birth (and beyond) is a continuum. (Kischer 1994, pp. 74–75)

In the spring of 1994, at the annual meeting of the History of Human Embryology, Kischer lamented that “Human Embryology was in danger of losing its base in Human Anatomy because the language of Human embryology was being pre-empted by Developmental Biology” (Kischer and Irving 1995, p. 123). In 1995 and in 1997, Kischer and Dianne N. Irving published a book entitled The human development hoax: time to tell the truth. In this book, they search for a number of embryology textbooks and try to collect evidence to prove that the term pre-embryo is what they call a “hoax”. Moreover, Kischer alludes to his own experience concerning the rejection of his works. Kischer mentions that his articles were rejected by a number of popular magazines, newspapers, and leading journals of medicine and bioethics – like the New England Journal of Medicine and the Kennedy Institute of Ethics Journal – without peer review prior to the final acceptance of his works in the Linacre Quarterly, a pro-life publication (Kischer and Irving 1995, pp. 110–119). Kischer (2005) also sent his statement to developmental biologist Scott Gilbert and geneticist Lee Silver. Both disregarded Kischer's argument. The response of Lee Silver was quite interesting in Kischer's words, “[Silver] declared that Human Embryology was devoid of molecular biology … By claiming that Human Embryology is really developmental biology, [Silver] in effect wipes out a 25000-year-old history of Human Embryology.”

The statement of Kischer about Lee Silver shows that the pre-embryo debate is not merely a small debate of specific scientific facts within one unified science but rather a bigger debate of two scientific fields of embryology, or the debate between developmental biology and human embryology. Lee Silver (1997, p. 39), however, endorsed a general critique of the term pre-embryo later, saying that this term is used to create “the illusion that there is something profoundly different” among the stages of embryological development:

The term pre-embryo is useful in the political arena – where decisions are made about whether to allow early embryo (now called pre-embryo) experimentation – as well as in the confines of a doctor's office, where it can be used to allay moral concerns that might be expressed by in vitro fertilization patients. “Don't worry,” a doctor might say, “it's only pre-embryos that we're manipulating or freezing. They won't turn into real human embryos until after we've put them back into your body. (Silver 1997, p. 39)

As will be detailed further later, Silver's statement became useful for AP bioethicists to criticize both developmental biologists and PP bioethicists. 9 The term “pre-embryo” is nevertheless being reproduced and backed by developmental biologists and gynecologists (see ACOG 2004, p. 92, Gilbert et al. 2005). A tension between embryologists and developmental biologists about the term “pre-embryo” remains strong.

On the other hand, AP bioethicists have called into question the term “pre-embryo” and the notion of individuality. Edmund D. Pellegrino (1999), Director of the Center for Clinical Bioethics at the Georgetown University Medical Center, and chair of the President's Council on Bioethics (PCB) insists that this term is “arbitrary”:

Individuality is not the same as personhood; it is a necessary, but not sufficient, condition. Many individual substances are not persons. Scientific evidence cannot resolve the dilemma of ontology, … Nor is the underlying science sufficient to support an arbitrary division of the line of development of the embryo into a stage called a “pre-embryo.” … Creating a category of “pre-embryo” is both biologically and ontologically arbitrary. It seems contrived to allow embryonic experimentation and destruction in accordance with the utility of the destruction for other persons.

Some AP bioethicists have provoked a semantic confusion by humanizing early embryos with the terms “embryonic human beings” and “tiny humans”. In particular, they have questioned the scientific legitimacy of the use of “pre-embryo” in order to erode the ethical position of PP bioethicists. They have insisted that their ethical views rationally build on embryology. For instance, Eric Cohen (2004, p. 101), editor of The New Atlantis and director of the Project on Bioethics and American Democracy at the Ethics and Public Policy Center, argues, “Religious opponents of embryo research make their moral argument by appealing rationally to the facts of modern embryology. And rational scientists make their moral case by appealing emotionally to the hardships of loved ones suffering from dreaded diseases.” In Cohen's argument, scientific credibility was deployed to undermine the ethical stances of PP bioethicists. This is scientism of ethical reasoning. It transformed ethical debates into credibility struggles of scientific claims around the term “pre-embryo”. This scientism generated a heterogeneous assemblage of AP bioethics and embryology.

Richard Doerflinger, Deputy Director of the Secretariat for Pro-Life Activities and US Conference of Catholic Bishops, has skillfully used the arguments of embryology. Doerflinger (2003b, p. 151) took a quote from geneticist Lee M. Silver (1997, p. 39) who claims, “I will let you in on a secret. The term pre-embryo has been embraced wholeheartedly by IVF practitioners for reasons that are political, not scientific.” Doerflinger also traced the origin of this term and found the works of O'Rahilly and Muller (1996), embryologists who criticized the term “pre-embryo”. Doerflinger notes, “Some textbooks that once used “pre-embryo” have quietly dropped the term from new editions, now describing the newly fertilized zygote simply as an embryo. Other experts openly dismiss the term “pre-embryo” as “discarded” and “inaccurate” (Doerflinger 2003b, p. 145). Doerflinger (1999) also raises a question about the commencement of developmental individuality, claiming that developmental individuality is very early established prior to the emergence of the primitive streak.10 Doerflinger insists:

[A]n embryo's potential for spontaneous “twinning” is established very early, largely by factors determining the thickness of the zona pellucida –so that the vast majority of embryos, from the outset, do not have the property of producing twins spontaneously. … And the mammalian embryo's spatial orientation is largely determined during the first week of development by signals in the outer cell wall or trophoblast, and some believe it may be determined at fertilization by the locus where a sperm penetrates the egg. (Doerflinger 1999, pp. 138–139)

Although the term “pre-embryo” has not been accepted by the official reports of the EAB, Human Embryo Research Panel (HERP), the National Bioethics Advisory Commission, and the President's Council on Bioethics (PCB), this semantic debate has occurred within some public hearings of these commissions. Richard Doerflinger (1994, 2003a) gave his testimonies involving the term “pre-embryo” before HERP and PCB. Dr. Dianne N. Irving (1994), a former research biochemist at the NIH/NCI in radiation biology and Professor of Philosophy at the Dominican House of Studies, also gave a relevant testimony before HERP. Her statement evidences scientism of ethical reasoning again:

“[D]elayed personhood” – fabricated in order to justify theoretically what is in fact unethical – have been grounded precisely on this “fake” human embryology, which has led to equally “fake” conclusions about the moral and legal status of human embryos … I would add that even Clifford Grobstein himself – who is not a human embryologist, but an amphibian embryologist – agreed with me, in front of a scientific conference, that his “embryology” was wrong, but that he was “just trying to be helpful”! … ethical scientists will go down with a handful of unethical scientists, so too will these good and ethical people in “bioethics” lose their own credibility in time because of the arrogant and intellectually abusive theories and practices of the unethical ones. (Kischer and Irving 1995, p. 250)

HERP (1994, p. 35) finally adopted the term “preimplantation embryo” instead of “pre-embryo”. A former HERP member Ronald M. Green argues that “preimplantation embryo” is a “misnomer” for early embryos prior to the emergence of the primitive streak because “implantation normally occurs at about six to seven days of development in vitro”. He mentions that HERP “chose the technically imperfect but more neutral term ‘preimplantation embryos’” to avoid criticism from anti-abortion groups (Green 2001, pp. 6–7).

One of the most recent critiques of AP bioethicists on the term “pre-embryo” was made in July 2006 at the American Society for Bioethics and Humanities (ASBH) Summer Conference titled “Bioethics and politics: the future of bioethics in a divided democracy”. This conference invited both conservative and liberal bioethicists to discuss the politicization of American bioethics. At this conference, Richard Doerflinger issued his statement about “pre-embryo” again in front of many American bioethicists.

Conclusion

This paper has explored how both PP and AP bioethicists created scientific knowledge-claims to defend their ethical claims in the “pre-embryo” debate. Both PP and AP bioethicists are placed in two different scientific contexts. The ethical reasoning of PP bioethicists is in fact indebted to Grobstein, Flower, and Gilbert's developmental biology, while AP bioethicists' views also draw on Muller, O'Rahilly, and Kischer's embryology. This is not a debate between two conflicting ethical theories over a unified science, but instead a controversy between two assemblages of bioethics and science.

Scientific uncertainty around the term “pre-embryo” between developmental biology and embryology is reproduced by the credibility struggles between PP and AP bioethicists. This uncertainty results not merely from a scientific tension between two fields of embryology, but also from two assemblages of science and bioethics. Moreover, it is necessary to discuss the scale of scientific uncertainty in the “pre-embryo” debate in terms of whether this debate is just a debate of particular scientific facts around early embryos or it is more a debate of two scientific fields between developmental biology and embryology. Scientists mentioned above might think more of this debate in the former perspective because they believe in the authenticity of their own science. However, empirical evidence in this paper shows that it is not merely a small debate of particular scientific facts within one field of embryology but also a much bigger debate of two scientific fields between developmental biology and embryology.

The scientism of ethical reasoning is a driving force to transform the ethical debate into a scientific fact debate. This scientism is the best way to attain credibility from scientists and other bioethicists and to attack counterpart ethics. In a sense, science serves as flying buttresses to sustain the cathedral of ethics. Although each regards counterpart bioethicists' science as pseudo-science, a belief in the purity of their own science is maintained. My point is not that Grobstein's developmental biology is “fake” and Kischer and Muller's embryology is “right” and vice versa. It is rather that both PP and AP bioethicists believe in positivism on science, an illusion that scientific facts are value-neutral. This belief has not been adequately questioned by either camp of bioethicists. Moreover, the point is not that bioethicists should wait for the moment when this scientific debate is closed. That moment will remain forever elusive. The difficulty of bioethicists is to make an ethical decision under a scientifically uncertain condition. However, bioethicists cannot and must not avoid this moment.

It is problematic to think that uncertainty retard and ultimately make moral decision-making impossible. As political incrementalists point out (Lindblom and Woodhouse 1993), in some cases, uncertainty enables both decision-making and social consensus, while reducing uncertainty paralyzes them. As for bioethics, Jonathan Moreno (1995) has argued that moral uncertainty occasionally leads to moral consensus. However, scientism of ethical reasoning cannot save bioethics from scientific uncertainty. Instead of attempting to remove scientific uncertainty, moral decision-making should cope with scientific uncertainty. Rather than depending on the rationalist analysis of biological facts in moral decision-making, American bioethics should encourage the use of “social intelligence” that seeks “mutual adjustment” among diverse participants (Lindblom and Woodhouse 1993, Moreno 1995). Bioethics should be more a socially interactive learning process.

The pre-embryo debate is not a unique case of heterogeneous assemblages. Regarding stem cell research, bioethicists create ethical reasoning on the future imaginary of stem cell research as cell replacement therapy. Therefore, the medical potential debate between embryonic stem cell research and adult stem cell research is an important part of the ethical controversy among bioethicists. Bioethicists have created the technological justification of either embryonic stem cell research or adult stem cell research in order to support their ethical positions. As a result, the stem cell debate among bioethicists occasionally develops into a debate between one assemblage of some bioethics and embryonic stem cell research and the counter-assemblage of counterpart bioethics and adult stem cell research. This phenomenon parallels the “pre-embryo” debate. As such, rapid bioethical intervention into emerging science and technologies will produce a number of heterogeneous assemblages. To cope with scientific uncertainty resulting from such phenomena of heterogeneous assemblages, bioethics needs to move beyond the scientism of ethical reasoning. Bioethicists should be more reflexive about the social situatedness of their own scientific and bioethical knowledge.

Acknowledgements

An earlier version of this paper was presented at the 2006 Annual Meeting of the Society for Social Studies of Science, Vancouver. This paper is largely indebted to Jill Fisher's thoughtful and detailed comments. I am also very grateful to Mike Fortun, Linda Layne, Nancy Campbell, Michael Flower, Michael Lynch, Jonathan Moreno, and Doogab Yi.

Notes

See Jasanoff (2005) and Mulkay (1997) for the “pre-embryo” debate in the United Kingdom. Since the 1970s the human embryo debate has been international and there have been significant interactions between the US and UK debate. In the United Kingdom, the term “pre-embryo” was introduced by Dr Anne McLaren in the Volunteering Licensing Authority in 1986, the same year when the Ethics Committee of the American Fertility Society adopted this term in the United States (Trounson 1993, p. 14). The Authority had been established by the Royal College of Obstetricians and Gynecologists and by the Medical Research Council to implement some of the recommendations of the Warnock Report (Jones 1989). Dr Anne McLaren was a member of the Warnock Committee and of the Volunteering Licensing Authority. Clifford Grobstein mentions Anne McLaren in his book: “I fully agree with McLaren who, in responding to a suggestion that the term preembryo is a ‘cosmetric trick’ (presumably to avoid constraints placed on ‘embryo research’), stated, ‘There is ambiguity in the way scientists use the term “embryo” – and we are not justified in continuing to use the term embryo in both senses. We are not talking about cosmetics but about clarity’” (Grobstein 1988, p. 62).

There are a variety of liberal moral status of early embryos such as sentience (Steinbock 2001), “developmental potential”, “the semblance of human bodily form”, “some degree of developed cognitive ability”, and “independence existence” (Green 2001, p. 63). However, the term “pre-embryo” is mainly related to the idea of “developmental individuality” (McCormick 1991).

I should note that there is a problem with language in this paper. I make a distinction between classical embryology and developmental biology although contemporary development biologists call their field a “new embryology” and “modern embryology” (see Gilbert 1991, Gilbert et al. 2005). I define classical embryology as embryology, while referring to “new embryology” as developmental biology.

It is necessary to note a slight difference between PP assemblage and pro-research groups at large in the human embryo debate. The former is the alliance where stakeholders agree with the use of the term “pre-embryo”, while the latter is referred to as groups which endorse the use of human embryos as research materials. PP assemblage definitely belongs to pro-research groups but the latter is not always identical to the former, because some can disagree with the term “pre-embryo”, although they have pro-research position. See note 9.

In explaining the “co-production” between natural order and social order, Sheila Jasanoff (2004) makes a distinction between “constitutive” co-production and “interactional” co-production. “Constitutive” co-production considers that social order is constitutive of natural order, in contrast to “interactional” coproduction: that social order parallels natural order in the first place and then interacts with each other. My idea of heterogeneous assemblages is closer to “interactive co-production”. To put it in the context of bioethics, science always creates moral order: however, the moral order is not always identical to another moral order created by bioethicists. I mean that bioethics and science have their own lives, but can parallel, or can entangle with, each other at certain moments. This paper claims that PP bioethics is entangled with developmental biology, while AP bioethics is entangled with classical human embryology. The entanglement of bioethics and science that arises in heterogeneous assemblages designates a causal relationship between bioethics and science, while parallelism refers to non-causal cultural correspondence between bioethics and science. My distinction between “causality” and “correspondence” draws on David Hess' (1995, p. 20) cultural constructivism which stresses the mapping of identical meanings. Even if the relationship between bioethics and science were not causal, if they would correspond to, or parallel, each other; both have a significant relationship in the realm of cultural constructivism. Heterogeneous assemblages are preceded by cultural correspondence. In other words, the entanglement of bioethics and science does not take place in thin air but it happens over cultural correspondence between bioethics and science.

Keller (2000, pp. 112–113) claims that “if one important gene is deleted from an animal's DNA, other genes apparently can stand in for the missing player … built-in genetic redundancy is surely essential to survival … Genetics, as it is sometimes said, is blind to redundancy.”

The earliest reference of the term “pre-embryo” can be traced back to McNaughton (1960) where the term was, however, used without explanation. I would like to thank an anonymous reviewer of this journal for this point.

The term “pre-embryo” is also found in Singer et al. (1990) and Carson Strong (1997).

The case of Lee Silver demonstrates a slight difference between PP assemblage and the pro-research group I mentioned in note 4. Although Silver has a pro-research position, he disagreed with the use of the term pre-embryo. Silver belongs to a pro-research group, but is not in the PP assemblage. Lee Silver is one case of disentanglement from the PP assemblage within the pro-research group.

For a similar argument, see Ashley and Moraczewski (2001, p. 196).