3.1.1 Morality and law are concerned with the respect that is due to human beings as moral subjects. People are not reducible to the sum of their physical parts or their biological drives. Mature and competent human beings can make decisions for themselves, for which they are held responsible both morally and legally. Furthermore, all human beings are members of the human community, whether or not they have come to full maturity, and all share a common humanity.
3.1.2 No human being is to be thought of as a mere physical object or a mere animal, for all possess a common dignity or significance that is not shared with any other animal.18 However, it is also important to stress that human beings are animals - of a particular sort. We should not think that the real person is a ghostly spirit inside the head (the mind or consciousness) or a demon who has taken possession of a body - as though the living human body were one thing and the person were something else. This would degrade the human significance of the body and undermine the conviviality and bodily communication that help to constitute the human world.
3.1.3 The Greeks defined a human being as a “rational animal” and this seems to capture something of the essence of a human being, as long as we are careful not to define “rational” in too narrow a fashion. Similarly the philosopher Boethius defineda subject (persona)19 as an individual being which has a rational nature: persona est rationalis naturae individua substantia.20 These definitions have the great virtue of simultaneously acknowledging the unity and the transcendence of the human individual.21 The human being is not two things joined together (a thinking thing and a physical thing) but one whole being.
3.1.4 It may seem that in the modern Western world, there is little danger of “dualistic” ideas posing a real threat. However, there seems to be something in the Western way of life and in modern culture that encourages, on the one hand, a view of political and technological freedom as unlimited by any rules concerned with human nature and, on the other, a view of the body as purely mechanical and empty of any intrinsic human significance.
3.1.5 The human moral subject is the human being, who is, essentially, a very special animal. We should not be afraid to admit that we are animals, members of the species homo sapiens, and that our lives are the lives of these living human bodies.22 Human individuals are biological individuals. The question nevertheless arises: when and how does this human individual come to be? And does he or she possess full human moral status from the very beginning?
3.2a.1 In species which reproduce sexually, a new organism comes to be with the successful fusion of the gametes. This is a rule that applies not only to human beings but reflects the very nature of sexual reproduction. The offspring are genetically distinct from the parents, so that the moment of generation of the new individual is clearly defined. “Fertilisation is the process whereby the two sex cells (gametes) fuse together to create a new individual with genetic potential derived from both parents.”23
3.2a.2 If the distinction between gametes and embryo is clearly defined, so too is the continuity between the single-cell zygote and the multicellular adult organism. “In nearly all cases the development of a multicellular organism begins with a single cell - the fertilised egg, or zygote.”24 While there are identifiable stages in the process of division, pattern formation and differentiation, the process itself is gradual and continuous. If one asks when and how development begins, the biological answer is clear: “development begins with the fertilised egg, which is a single cell, giving rise to a number of smaller cells.”25
3.2a.3 Progress within the science of developmental biology has done nothing to displace this most fundamental of starting points. The basic biological outlines of human development are not controversial: fertilisation initiates a cascade of developmental events and is the universal terminus a quo for considering embryonic development. The fertilised ovum, termed a zygote (the single-cell phase) or a conceptus (the general term for the product of conception), is also termed an embryo from fertilisation until the end of the second month when it is designated a foetus. Thus, from a biological perspective, the product of fertilisation is a new organism, an embryo in the process of development. “After these gametes combine, a new organism begins to develop.”26
3.2b.1 Biologists generally consider the new individual organism to begin with fertilisation. Fertilisation is a process that takes time - in human beings it takes about 24 hours from the first contact between the ovum and spermatozoon to the union of the chromosomes (“syngamy”) and the first cell division - yet there is a point within this process when the most significant phase has been accomplished (when the process is essentially complete). From this point a new biological organism exists. However, some people have suggested that the embryo does not begin to exist when fertilisation is complete. They point out that most of the cells of the conceptus (95% at the 64 cell stage) go to make the placenta and amniotic sac, and claim that, until the embryo “proper” is clearly differentiated from these other structures, the human individual does not yet exist.
3.2b.2 These critics are right in saying that the distinction between the placenta and the embryo “proper” is not present immediately after conception. The placenta takes time to develop. However, they are mistaken in thinking that this distinction is a distinction between the embryo and something else. The placenta belongs to the embryo; it is an organ of the embryo by which it takes nourishment from its mother. If the amniotic sac and the placenta are understood as parts or organs of the embryo, then the appearance of these structures will be no more or less significant than the genesis of other embryonic structures. A new identifiable human individual already exists from the beginning, before these specialised structures start to appear.
3.2c.1 A second phenomenon is more difficult to comprehend. Whereas most embryos develop into a single adult organism, a small number (0.3%) undergo division at an early stage so as to produce identical (or “monozygotic') twins. The process of identical twinning is often thought to demonstrate conclusively that the early conceptus is not an individual. If a biological object is to be described as an individual organism it requires a certain level of integration, such that it is not just a collection of cells held together mechanically but a single integrated unit. Some claim that the phenomenon of identical twins shows that the early conceptus is not a unitary organism but only a loose collection of cells yet to develop into an organism or organisms.
3.2c.2 A survey of textbooks of developmental biology shows that the embryo is more than an aggregate held together by mechanical forces. “From the outset, the cells of the embryo are not only bound together mechanically, they are also coupled by gap junctions.”27 Nor do biologists regard the phenomenon of twinning as something to be explained as the breaking up of a loose aggregate. They regard twinning as evidence of a power possessed by the embryo to redirect cells that normally would have contributed to only a portion of the embryo, a power they term regulation.28 This is a power of the embryo as a whole, rather than of individual cells. “Since early vertebrate embryos show considerable capacity for regulation and many of the cells are not determined, this implies that cell-cell communication must determine cell fate.”29
3.2c.3 Identical twinning is an exceptional event proving the rule that, in general (in 99.7% of cases), only one foetus develops from each zygote. Where identical twinning does occur, the twinning event (whatever this is) triggers the formation of one or more discrete organized wholes, each in the process of development.30 Each newly generated twin then continues as a well-formed individual. It does not form just half a foetus, nor does it grow wildly as a teratoma. Both in singletons and in identical twins, early human embryology shows a strong commitment to the development of distinct organized individuals.
3.2c.4 Biologically speaking, the early embryo is a well-integrated whole which, even in the rare cases when it splits, does so in such a way that one or more well-integrated individuals are formed. However, it might be argued, do not even these rare exceptions undermine a principle that is supposed to be absolute? If the conceptus could split, or could be made to split, does this not show that it is not yet a genuine individual, even in those cases where it goes on to become an individual?
3.2c.5 This argument relies on the principle that whatever is an individual cannot give rise to other individuals. This principle may once have seemed plausible; however, it is undermined by the very possibility of human cloning. In many living things, including some vertebrates, reproduction can occur asexually: by a parent-cell splitting to give two daughter-cells; or by a new organism budding off from a continuing parent. The suggestion that adult human beings might one day be cloned assumes that human beings can be reproduced asexually - without this compromising the individuality of the human being who generated the clone.
3.2c.6 There is ample evidence for strong integration in the early embryo, both in the case of singletons and in the case of identical twins. From the perspective of biology it is clear that there is one individual which endures from the single cell stage until the death of the multicellular organism - except in the case of identical twins, who are natural clones produced early in development by asexual reproduction. Furthermore, as soon as these twins come to be, they also endure as individual organisms until their own deaths. The normal habit of biologists is to count embryos: to test them, select them and transfer them. In all these actions it is assumed to be unproblematic that even early embryos are a discrete number of individual living organisms such that they can readily be counted.
3.3a.1 Human subjects are to be respected by others and protected by society. Though every concrete human society seeks to limit those who can be accounted full members or citizens, there is a certain minimum protection that is generally thought due to every human being, whether a full citizen or not. The classification of some categories of people - especially foreigners, criminals, slaves, the mentally ill, women, children, and the disabled - as less than human was explicit in many ancient and even in some modern societies. It was in reaction to the horrors of Nazism that the United Nations sought to frame a list of basic “human rights” possessed by all people irrespective of their situation, simply on the basis that they are human beings. “Human rights” language assumes the existence, or at least the possibility, of a universal community to which all human beings belong. Human rights are those things which are owed to a human being simply in virtue of being human.
3.3a.2 The moral insight basic to the very idea of human rights is that the human moral community naturally extends to all human beings, so that the exclusion of some category of human beings as subhuman is arbitrary and unjust. Human beings are revealed to be moral subjects by their thoughts and their mature free decisions, but those who are too immature or incapacitated to exercise these capacities are not to be discriminated against on the basis of what they cannot do. Human dignity resides in what human beings are rather than what they can or cannot do at any particular moment. All forms of society favour the full-grown and the strong and the bright, but these favoured few should not consider themselves more worthy of protection than the weakest or least able.
3.3a.3 Consider the protection due to a newborn infant. Not only the parents, but the great majority of people, recognize the child as more worthy of protection than the adult because more vulnerable. Physical abuse of small children rightly provokes a sense of horror or outrage, and few things are more shocking than the death of a child. The old and the sick are less immediately attractive than little children, but again, the sight of an old person who has been violently assaulted is viewed as monstrous precisely because the victim was so vulnerable.
3.3a.4 The newborn infant, the mentally disabled adolescent and the Alzheimer's patient are no less human, and no less worthy of the protection of society, than the healthy worker or the brilliant student. They are all, equally, members of human society, which is, or ought to be, for the benefit of all. The human being who is mentally impaired or who has lost the use of his or her faculties is in a deprived state, but is not thereby subhuman. The newborn infant cannot speak or understand any more than a dog or cat, but he or she is already human, and it is this humanity that is the basis for his or her developmental potential. The baby is human, someone's son or daughter, with a human future in store. The significance simply of being human is immediately recognized by men and women of good will and is the basis of efforts in civilized societies to protect children and to secure better treatment for the mentally impaired. Human infants have an interest in health, in a stable family and in a future, even before they can take an interest in these things.
3.3b.1 Many people who would strongly oppose discrimination on the basis of age or mental capacity, and who would defend the rights of children born with a disability, do not see the protection of five- or six-day-old human embryos in the same light. Whereas it is obvious to them that disabled children are human beings deserving protection, the same is not obvious in the case of human embryos. This may be for several reasons. Some do not consider human embryos to be human individuals. Others consider the allegedly high level of natural wastage of embryos points to their lack of worth. Finally there are many who simply cannot believe that the embryo is a human being because it appears to be just a ball of cells.
3.3b.2 Essential to the proper understanding of the human embryo is that it is not just human life, but a human individual; that is to say, an integrated human organism. This has been argued at length in the previous section and, when contentious moral questions are not foremost in people's minds, there seems to be no problem in regarding human embryos as discrete biological individuals. The fact that one embryo occasionally produces two does not undermine the empirical observation that it was genuinely one before and genuinely gives rise to two after.
3.3b.3 The number of ova which are successfully fertilized but without the embryo implanting is subject to much dispute with many conflicting estimates. It seems that there are abnormal fertilisations giving rise to products which are so disordered as to lack all human developmental potential and which should not be regarded as embryos or as human individuals but as pseudo-embryos. On the other hand, it would be fair to say that, even among those conceptuses showing serious chromosomal abnormalities, many of these would be children suffering from severe disability, rather than pseudo-embryos.
3.3b.4 Even if the normal level of wastage before implantation were “only” 10-15% this would still amount to tens of thousands of embryos each year in Britain alone. Is this a cogent argument against attributing human status to the early embryo? High mortality may sometimes have the social effect of cheapening human life, but this is not a moral argument for taking this attitude oneself. In human beings, as in most animals, it is the young who are most vulnerable, and throughout history high rates of infant mortality have been the norm. This is still the case in many parts of the world. High rates of infant mortality probably contributed to the culture of the ancient world in which infanticide was regularly practised, but it did not justify the practice. Nature is sometimes cruel, but “the survival of the fittest” is no guide to justice in society, and the prevalence of high mortality is no guide to the moral status of the human embryo.
3.3b.5 It seems likely that neither the phenomenon of identical twins nor the rate of spontaneous embryo loss would have been given much weight if the individual in question had only looked more like a child. Newborn babies cannot exercise the human powers of speech and reason, but the potential they have is clearly rooted in their existing humanity. The mentally impaired, the sick and the old may be disabled and even disfigured, but they have human faces and human flesh and blood. The early embryo looks very different and does not easily evoke the concern or compassion evoked by a child or a comatose adult. Society recognises the human status of those with unrealized or frustrated human potential, but in every case this is based on an acknowledgment of the visible humanity of the person. It is precisely this which is in question in the case of the early embryo.
3.3b.6 Appearance is important, and immediate human sympathy or compassion is an important weapon in overcoming cultural prejudice against certain categories of human being. However, it is the task of moral reasoning to criticize our immediate emotional reactions and expand our moral horizons. The early embryo, whether produced by fertilisation, by natural cloning (identical twinning) or by artificial cloning (cell nuclear replacement), is a biological individual, a developing human being in the earliest stage of life who, if allowed to develop, could enjoy a human future. Killing a human embryo is unjust for the same reason that killing an unwanted newborn child is unjust: because an innocent human being is deliberately destroyed and robbed of a future.
3.3b.7 Throughout history some human beings who were undeniably human, but who were different from others because of sex, race, age or disability, have been accorded a graded “respect” without “equality'. In each case the rhetoric of difference was invoked in defense of injustice. The basis of this injustice was the very existence of the category of a human being who is not a member of human society, a subhuman or untermensch, a category which was firmly rejected by the UN declaration of human rights. Human embryos are human individuals who, given time and opportunity, will grow into older human beings. They are no less human than any other human being but only younger and less aware, more vulnerable and less able to arouse our compassion.
Next Page: Respecting the embryo
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