Bioethics

A Philosophical Introduction

Stephen Holland

• Publisher: Polity
• Year: 2016
• ISBN:
  9780745690636
• Edition: 2
• Topic: Filosofia
• Subtopic: Filosofia etica e morale

This book provides a clear and comprehensive introduction to contemporary bioethics. It also presents provocative, philosophically informed arguments on current bioethical issues. Holland engages with debates ranging from the more familiar – such as euthanasia, advance decisions to refuse treatment, and new reproductive technologies – to the philosophical implications of recent developments in genetics, including prenatal genetic therapy, genetic enhancement and human cloning. The book is built around four crucial themes. The first is moral status: what are the implications of the moral status of human embryos or animals for our biomedical practices? The second theme – life, death and killing – looks at the ethics of ending, or failing to lengthen, human life. Holland then explores various questions of personal identity raised in contemporary bioethical debates. Finally, he presents and develops a version of the argument from nature – which continues to be influential in bioethics – in order to make sense of the objection that some biomedical innovations are unnatural. Structuring the discussions in this way creates an engaging introduction to bioethics that is an ideal textbook for students, whilst offering much to stimulate colleagues in the field. This second edition has been thoroughly and comprehensively updated to reflect the most recent advances in bioethics, and includes an entirely new chapter on the ethical treatment of patients in the minimally conscious state.

Part I
Moral Status

Introduction to Part I

All bioethical issues involve entities that are morally relevant or significant because they have moral status. To have moral stature is to be an object of moral concern, and moral agents owe duties and obligations to an entity with moral status. For example, sentient creatures have moral stature because they are bearers of rights or their interests count. So in addressing bioethical problems, it is always important to look closely at the moral status of the entities relevant to them (cf. Sachs 2011). With this in mind, part I discusses two current bioethical issues, namely, stem cell therapy and xenotransplantation, in chapters 1 and 2, respectively. The entities relevant to stem cell therapy are persons – patients who stand to benefit from the therapy – and the very young embryos that would be used to develop and provide the therapy. The entities relevant to xenotransplantation are animals – i.e., non-human animals, such as baboons and pigs – which would be used as organ sources, and human beings, including both patients who stand to benefit from xenotransplants, and human non-persons, such as anencephalic infants, who might be an alternative organ source. Grounds for the moral status of these are discussed, and the ethics of stem cell therapy and xenotransplantation are considered in the light of this.

1
Stem Cell Research and Therapy

The aim of this chapter is to address the ethical permissibility of stem cell research and therapy. The focus is on the moral status of those affected by this innovative branch of regenerative medicine. The relevant parties are patients who are potential beneficiaries of stem cell therapies and the human embryos destroyed in stem cell research. In 1.1, stem cell therapy itself, and the general worries about its permissibility, are outlined. Then the grounds for the moral status of the two affected entities are explained. The moral status of patients is relatively uncontroversial; as explained in 1.2, this is based on the value of ‘persons’ (a term with a more precise meaning in bioethics than in everyday speech). The moral stature of the human embryo is more interesting and contentious. There are two ways of grounding the moral status of embryos. The first is discussed in 1.3 and focuses on identity: is the human embryo already an individual human being? The second, discussed in 1.4, is that the embryo is morally significant not because it already is an individual human being, but because it has the potential to become one. It is difficult to envisage either approaches resulting in a consensus on the moral status of embryos. So perhaps the ethical treatment of embryos should be addressed more directly and not via questions about their identity or potentiality. This approach is taken in 1.5 but also found wanting, so the chapter ends on a sceptical note. We are still in something of a quandary when it comes to the moral status of embryos and, in turn, the permissibility of stem cell research and therapy.

1.1 Stem cells and regenerative medicine

Many serious medical conditions are caused by the demise of cell tissue due to degeneration, damage or disease. This includes damage to heart tissue due to heart disease, neurodegenerative disorders such as Parkinson's and Alzheimer's disease, spinal cord injuries to nerve cells, and severe burns that destroy skin cells. The crucial thing about stem cells is that they can transform into other types of cells, such as muscle, nerve, heart, blood and skin cells. So, feasibly, new cell tissue of the relevant type could be produced from stem cells and the resultant material could be transplanted into patients to repair or replace damaged tissue. This is a category of what is generically referred to as regenerative medicine (Mao and Mooney 2015). For example, stem cells could be transformed into cardiac cells and transplanted into a patient suffering heart disease, thereby repairing their damaged organ. It is also considered feasible to grow stem cells into an entire transplant organ, though as yet it is unclear whether they can be cultivated to the level of organization required. There are other important, though less dramatic, potential benefits. Drugs could be tested on cultures of specialist cells (liver, skin and so on) derived from stem cells, as opposed to people; and stem cell research offers opportunities to improve our understanding of human development. Another even more futuristic-sounding possibility is to use stem cells to develop therapies to increase lifespan. (For summaries of the state of scientific affairs, see DoH 2000; Holm 2002: 493–7; Li et al. 2014.)

Stem cell research and therapy present a myriad of ethical worries. There isn't space here to discuss all these but at least the main ethical controversy can be clarified, and a way of structuring the issues will be suggested. The first thing to note is that investigation into the therapeutic potential of stem cells is still fairly nascent. In fact, it is arguable that potential benefits of regenerative medicine have been overstated and potential beneficiaries are misled into thinking that stem cell therapy is more imminent than is the case. ‘Stem cell tourism’ – i.e., patients going abroad for unregulated and unproven treatments – is a case in point (McMahon 2014). On the other hand, regenerative medicine promises such enormous medical benefit that only a fraction of the potential therapeutic value of stem cells has to be realized to make a huge difference to patients. Because our thinking about stem cells is in its infancy, numerous future developments are possible, most of which invite ethical worries. Many of these are familiar from other biomedical procedures, such as embryo research, abortion and assisted fertility; in fact, the issue discussed fully in this chapter, the moral status of the embryo, is a case in point. But stem cell therapy adds new urgency to these, as well as raising some distinctive concerns. (For summaries of ethical issues, see Holm 2002: 497–507; Lo and Parham 2009.)

A way to structure one's thinking about the controversy is to distinguish ways of acquiring stem cells. Stem cells are found in embryos, foetuses and adults (throughout this chapter, ‘embryo’, ‘blastocyst’, ‘foetus’, and the like, are used to refer to human ones). Let's take each in turn, starting with embryos. At about five days or so, an embryo develops to become a blastocyst from which pluripotent stem cells can be extracted. These cannot produce an entire adult human because they can't give rise to tissue, such as the placenta, required for full embryonic development (as opposed to the preceding totipotent stem cells which can). An important distinction here is between ‘spare embryos’ created as part of a fertility treatment programme – for example, IVF produces unused embryos (see chapter 9) – and ‘research embryos’ created for the purpose of extracting stem cells (Devolder 2005). There is a further important distinction because stem cells could be extracted from cloned embryos produced using somatic cell nuclear transfer (see chapter 11). This process involves removing the nucleus of an oocyte (the female germ cell, or egg) and replacing it with the nucleus of a somatic cell (such as a skin cell) taken from the patient to be treated by stem cell therapy; stem cells would then be extracted from the resultant blastocyst.

Apart from embryonic stem cells, there are non-embryonic sources. Stem cells are found in the primordial germ cells of foetuses – germ cells are those that would develop into sperm or egg cells – so stem cells can be extracted from electively aborted foetuses. Adult stem cells are found in the blood cells of umbilical cords at the time of birth; also, mature humans carry stem cells around with them – for example, in bone marrow – albeit in progressively decreasing numbers. Adult stem cells are a major part of contemporary regenerative medicine because it is hoped that they could be reprogrammed to become ‘induced pluripotent stem cells’ (iPSCs), which would have the pluripotency, and so the therapeutic potential, of embryonic stem cells. Finally, a stem cell line starts with a single pluripotent stem cell which is cultured in a lab to produce a group of identical stem cells that are ‘immortal’ in the sense that they can be extended indefinitely.

Evidently, there are numerous sources of stem cells – doesn't this help to alleviate the ethical problems? Why can't we simply use stem cells from ethically unproblematic sources? Unfortunately, things are not so straightforward. For one thing, some of these potential sources of stem cells are more morally problematic than might appear. For example, cloning stem cells sounds promising because a recipient's body would not biologically reject materials developed from stem cells extracted from their cloned embryos; but therapeutic cloning is ethically very controversial, especially to those who see it as the top of a slippery slope to human reproductive cloning (see chapter 11). Likewise, since abortions are sanctioned in many jurisdictions, there seems to be no great moral step required to extract stem cells from aborted foetuses. But, of course, an anti-abortionist would disagree, and there is long-standing worry that stem cell therapy would provide an inducement to abort (Polkinghorne Review 1989).

Still, one might think that, even if there are ethical qualms about using stem cells from these sources, at least some stem cells are unproblematic. The obvious candidates are iPSCs which would be extracted from adults and reprogrammed; and it would be better to use stem cells from spare embryos and existing stem cell lines for beneficial research purposes rather than simply destroying them. But both these seemingly unproblematic sources of stem cells turn out to be contentious. Regarding iPSCs, it is proving very difficult to reprogramme adult stem cells to make them behave like embryonic pluripotent stem cells, so embryonic stem cells remain the ‘gold standard’. This creates a dilemma: adult stem cells are ethically least controversial but have less therapeutic potential; embryonic stem cells are therapeutically most promising but ethically very controversial. Furthermore, even if adult stem cells could be successfully reprogrammed, developing stem cell therapies would require considerable research using embryonic stem cells, so the tricky ethical question about using embryos would not be avoided (Hyun et al. 2007).

Likewise, spare embryos and existing stem cell lines remain stubbornly problematic. On the one hand, it is argued that it is morally permissible – even obligatory – to use embryos left over from well-intentioned interventions (such as fertility treatments) and existing stem cell lines (which can be extended indefinitely) but not to create new embryos solely for research purposes. Sometimes this is put in terms of ‘the principle of waste avoidance’, and it is the basis of the relaxation by the Obama Administration of the ban on stem cell research in America. But opponents argue that it is morally impermissible to benefit from the unethical destruction of embryos, whatever the intentions behind the original intervention (Manninen 2007).

In sum, stem cell therapy is a hugely exciting branch of regenerative medicine which remains ethically very controversial because of the destruction of embryos in stem cell research. The aim of this chapter is to address the ethics of stem cell research and therapy via the notion of moral status; in particular, to reflect on the relative moral status of the patients who would be recipients of stem cell therapy and the embryos which are destroyed in stem cell research. So the focus is on whether these entities have moral status; and, if so, on what grounds, and to what extent, relative to one another. The next section looks at the moral status of persons before we turn to the more involved question of the moral status of embryos (for an interesting critique of this approach to the issue, see the dialogue between Lysaght and Campbell 2014).

1.2 Persons

That persons have moral stature is so uncontentious that it might seem unnecessary to discuss it. Nonetheless, when the grounds for the moral status of persons are questioned, some interesting issues arise. First, let's consider some points about the development of the idea of ‘persons’.

Locke and Kant

Locke's famous discussion is a milestone in the development of the concept of ‘person’ (Locke 1997: II. xxvii; for comments on the concept of a person prior to Locke, see Poole 1996: 39–40). Locke does two important things: first, he separates out persons and human beings; second, he discusses identity conditions for persons, i.e., the conditions under which a person can be identified as someone in the past, and so held morally responsible for their actions. The first of these is important at present; the second is the theme of Part III. So, on Locke's account ‘person’ and ‘human’ are distinct categories: not all humans are persons, and perhaps not all persons are human. Locke went on to define a person as follows: ‘A thinking intelligent being, that has reason and reflection, and can consider itself, the same thinking thing, in different times and places.’ On this account, a certain psychological capacity, comprising rationality and self-consciousness, is the distinguishing feature of persons. In sum, Locke said that personhood is a distinctive state – being a person is not the same as being a human – and creatures achieve that state in virtue of distinctive psychological characteristics, such as rationality and self-consciousness.

A related line of thought is associated with Kant. Kant agrees with Locke that personhood is a matter of psychological capacities; but whereas Locke talked of rationality and self-consciousness in general, Kant associates personhood with a capacity for moral agency. Sometimes Kant's view is summed up in metaphors such as ‘persons are members of the moral community’. This is a bit obscure; to get inside Kant's thinking, it is useful to focus on his notion of freedom, or an autonomous will. For the most part, the world comprises things that ‘behave’ in ways that are causally determined; by natural laws, in the case of inanimate things, and by non-rational impulses and instincts in the case of animals. But a normal, mature human such as you or I is capable of, as it were, rising above this causal nexus and imposing its will on the world. This is due to our rational faculty, an ability to ‘stand back’ from the world, deliberate, and act on the basis of reasons. For Kant, the quintessential exercise of this capacity is moral action. This is captured in phrases such as: ‘ability to act in conformity to the moral law’. In other words, a paradigmatic exercise of the capabilities Kant had in mind is when an agent works out their duties, and acts out of a sense of duty. Uniquely, persons have this capacity and it ensures their moral status.

What status does this confer on persons? According to Kant, ‘everything has either a price or a dignity....