Abstract
In 2008 the UK Parliament passed the Human Fertilisation and Embryology Act, legislation which amended aspects of the 1990 statute of the same name but also introduced provisions permitting the creation of ‘human admixed embryos’ for the purpose of research. The Act defined human admixed embryos in terms of embryos formed from a variety of combinations of human and non-human genetic and cellular material, and laid out conditions under which the research on such embryos might be granted a licence. Among these conditions were that these embryos may not be kept beyond fourteen days, and may not be placed either in a woman or in a nonhuman animal. In adopting these provisions the UK planted itself firmly and deliberately at the liberal end of the spectrum of legislative responses to scientific developments: while no country has passed a law allowing the implantation and gestation of human–nonhuman embryos, most European and English-speaking legislatures, by contrast with the UK, are leaning towards prohibiting the creation of such embryos for research purposes, and some (such as Germany) forbid not just the creation but even the use of human embryos for research.
The Scottish Council on Human Bioethics (SCHB) has long been one of the most prominent and informed critics of these developments in interspecies embryo research, and this book is the fruit of their work. There are precious few book-length treatments of these troubling issues which are at all open to moral-theological approaches: as such this study is very welcome. As it happens the explicitly theological dimensions are distinctly muted—perhaps because the SCHB is formally a non-religious body and that is thought appropriate in this exercise in public ethics—but both Calum MacKellar and David Albert Jones are theologically attuned and much of the ethical analysis is of a kind that readily harmonises with moral-theological motifs. Unusually for a book presented as an edited volume, the editors are also the principal authors: most of the writing was done by MacKellar and Jones, although it incorporates some material by other scholars, notably on Buddhist and Islamic perspectives.
A definition of terms at the outset is usually the prelude to an insufferably formulaic treatment of a topic, but in this case it is essential for the avoidance of confusion, and MacKellar and Jones carry this off admirably. Roughly, a chimera is an organism that consists of cells of more than one organism or species, and thus a human–nonhuman chimera is an organism made up of genetically distinct populations of human and nonhuman cells; chimeras may be embryonic or foetal, but also include adult human beings who have received xenotransplanted organs such as pig heart valves. A hybrid is an organism in which the combination happens at a subcellular level, whether formed by a fusion of gametes (so-called ‘true hybrids’, such as mules, which are the offspring of male donkeys and female horses) or by the somatic cell nuclear transfer (‘cloning’) of the nucleus of a cell from one species into the enucleated ovum of another species (so-called cytoplasmic hybrids or ‘cybrids’). Transgenic individuals are those in which the interspecies transfer occurs at the level of the DNA, as a result of using various recombinant DNA techniques. As the generic term for all these, in the absence of any international agreement, the authors helpfully propose the term ‘human–nonhuman combination’.
This is followed by a thorough synopsis of the present state of national and international legislation, where they argue sharply that even in the most comprehensive legal regimes, such as the UK’s, there still remain major loopholes whereby research may fall in the gap between animal and human regulatory bodies. Given the pace of legislative change and the inevitable early obsolescence of printed overviews, this section would have benefited from some reference to website or other resources which could provide regularly updated information. The same applies to the following part, where they turn their attention to the present state of scientific research. The lamp of human inventiveness remains undimmed, it comes as no surprise to the reader to learn, even if those labouring to make intellectual and moral sense of what it has uncovered are struggling to keep up.
The third and longest part of the book turns to precisely this task of moral discernment, with a series of chapters on ‘cultural perspectives’, ‘worldview perspectives’ and ‘ethical perspectives’. The first of these is devoted in good part to public perceptions of these technologies, sympathetically analysing the oft-criticised ‘yuck’ reaction. While it is easy to dismiss this as mere visceral revulsion, it is not necessarily misplaced to find many combinations—they instance a pig with a chicken’s head—objectionable, not just for reasons of squeamishness but also because these do not represent functioning, integrated wholes. Such examples may incidentally bring to life for us something of the sensibility underlying the prohibitions against mixing of types in the Old Testament purity laws, as well as shedding light on the curious anomaly in the original 1990 Human Fertilisation and Embryology Act (apparently echoed in more recent Australian legislation) which allowed human embryos to be researched on until a fourteen-day limit, but required that hybrid embryos composed from human sperm and nonhuman eggs be destroyed no later than the two-cell stage.
The next chapter on worldviews is the least satisfactory of the book, covering in the space of sixteen pages Buddhism, Christianity, Hinduism, Islam, Judaism, evolutionism, materialism, humanism, pragmatism, Marxism, feminism and environmentalism: such rapid coverage is inescapably geared to superficiality, and for scholarly purposes the chapter should be left aside, with the exception of the brief but intriguing section on Islam.
By contrast, the chapters on ethical perspectives and ethical analysis are the most substantial of the book. Despite a certain amount of repetition and confusing exposition (it is not evident for example why discussion of an animal’s telos should be treated as one of the extrinsic rather than intrinsic moral concerns raised by this research), with some attention the basic structure of their argument against many forms of human–nonhuman combination becomes clear. While there are many extrinsic concerns (transmission of diseases across species barriers, environmental concerns, long-term consequences, and so on), the deepest problems are related to the intrinsic questions surrounding the ontological and moral status of the human–nonhuman combinations that result. In some cases (the transplanting of a pig heart valve into a human recipient, for example) it is plausible to think that no ultimate questions about human identity arise, whatever one’s views on the separate question of the harm done to the nonhuman animal donor. In other cases, however, such as the transplanting of brain tissue, it is much less clear: the transfer of animal neural cells into a person’s brain might lead to disorienting experiences or behaviours that led them to question their sense of self-identity. And in the case of the mixing of human and nonhuman gametes to form a new being of indeterminate status (think of the ‘humanzee’ which Stalin’s regime tried to create in the 1920s to fill the ranks of the Red Army), the question of identity is posed at its sharpest; indeed it is difficult not to feel that here visceral revulsion at the idea is the only proper response of a morally formed character.
MacKellar and Jones respond to the prospect of such entities through application of the notion of dignity. Against those who substitute dignity with autonomy, they argue that such an approach can offer no final reason for not taking the lives of those who have lost autonomy: in fact it is because people have dignity that we care for their autonomy, and not the other way round, and because of their dignity that we care for all persons equally, regardless of their capacity for autonomy. Against those who attribute dignity exclusively to human beings, they allow for the possibility—controversially, but in my view rightly—that full inherent dignity is in principle attributable to at least some other nonhuman species. The problem with deliberately creating such indeterminate interspecific entities is not that they could not be given the benefit of the doubt as to their moral standing, but that the persistence of doubt creates a ripple effect of further doubt, potentially sapping the foundations of the equal dignity of all human beings. Either we grasp the issue before embarking on such research, and agree that all such beings be given the benefit of the doubt and regarded as having the same full inherent dignity as human beings—which then raises the question of where further down the line the boundaries lie. Or better, and so the authors urge, we leave well alone.
All of this is of signal importance, at least to this reviewer’s mind. But it leaves one decisive issue unaddressed, namely that no one is pressing for the creation of such human–nonhuman combinations beyond the embryonic stage. Even the world’s most permissive jurisdictions do not allow implantation and gestation of interspecies embryos; as the authors agree, ‘[v]irtually no one defends the freedom of a scientist to seek to bring such a creature to birth’ (p. 166). As a practical rather than philosophical or speculative issue, the question only gains traction in relation to research on embryos. And this in turn makes one’s understanding of the moral ontology of the embryo crucial: for those who recognise the equal dignity of embryonic and adult human beings, these considerations about the status of interspecific combinations will certainly have weight; but for those who are inclined not to grant embryos much moral standing anyway, the existence of entities even less like adult human beings is scarcely likely to change their mind. MacKellar and Jones do make one significant rejoinder to this, namely that unlike the case of human embryos, creating interspecies entities at the embryonic stage is more problematic than creating them at foetal or later stages, since the depth of biological integration of human and nonhuman elements will be greater. The point is well taken, but even so, for the scientist happy to confine him- or herself to research on embryos this will remain irrelevant as long as the prohibition on implantation and gestation remains firmly in place.
One can imagine and indeed sympathise with reasons for not broaching the implications of the embryo’s status in this context in any detail; it is certainly not for reasons of coyness, as those familiar with Jones’s extensive writings on this subject will attest. But for the sake of completeness and clarity of argument, it would have been good to articulate it—and to do so in the final sections on ethical analysis, not just tucked away in the earlier chapter on ‘worldview perspectives’, where the theology is put. Separating theology from ethics may at times be rhetorically and pragmatically justified for the sake of a hearing in the public realm, but it always runs the risk of shielding the world from the questions that the Gospel poses to it.