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if individual parents were to make these kinds of reproductive decision themselves.

      Those who are most enthusiastic about genetic enhancement call themselves transhumanists to signify that they think it desirable to move beyond the human nature that we have inherited from the long and blind process of evolutionary selection. Nick Bostrom in “In Defense of Posthuman Dignity,” defends transhumanism against the criticism that if we change our nature, we will lose our human dignity. Though the idea of human dignity is often invoked, the values behind it are rarely made explicit. Bostrom distinguishes different things that we might mean by “human dignity.” He then defends, as the title of his essay indicates, “posthuman dignity” – that is the idea that there is moral worth in seeing human nature as dynamic and changing, and in seeking to make moral progress by improving it.

      Francis S. Collins was appointed Director of the United States National Institutes of Health (NIH), one of the world’s largest public funders of biomedical research, in 2009. Prior to that, he directed the National Human Genome Research Institute, in which capacity he played a leading role in mapping and sequencing the human genome. In his “Statement on NIH Funding of Research Using Gene‐Editing Technologies in Human Embryos,” Collins defends NIH’s long‐standing policy against funding research involving the use of gene‐editing technologies in human embryos. As he points out, NIH also does not fund research proposals that alter genes in ways that may be passed on to future generations. Collins notes that some of this research is being done in China, and cites legislation and regulations that exclude the possibility of such research in the US.

Giulia Cavaliere’s “Genome Editing and Assisted Reproduction: Curing Embryos, Society or Prospective Parents?” focuses on whether genome editing might be preferable, for ethical reasons, to preimplantation genetic diagnosis (PGD), which is currently in use in several countries, including the United States. Cavaliere evaluates two sets of concerns about the use of genome editing on human embryos or gametes in a clinical setting: safety concerns and ethical objections to introducing changes into the human germline. In this context she cites, and gives reasons for rejecting, the position taken by Francis S. Collins in the statement included in Chapter 16 of this Anthology. She then discusses the potential benefits of genome editing, given that it would not be vulnerable to some of the ethical objections to PGD, and could be used in cases where PGD is ineffective.

      Cavaliere cautions us to assess thoroughly the safety of genome editing, but she does not find compelling the claim that it is wrong to introduce any modification of the human germline. She argues, however, that societies need an ethical policy for allocating social resources so as to ensure equality of access to assisted reproduction, including assistance that which makes use of genome editing.

      R. Alta Charo asks us in her article “Who is Afraid of the Big Bad (Germline Editing) Wolf?” to be wary of unsubstantiated claims about significant dangers associated with human germline editing. She argues that time and again in human history, when biomedical research offered society new technologies and possibilities, there have been dire warnings and predictions about their supposed risks. Among others she mentions the argument that germline editing could turn children into commodities. The same types of arguments were raised historically by opponents of the introduction of, for instance in vitro fertilization (IVF), surrogacy, and PGD. None of these worries turned out to be justified. Charo’s concern is that societies might give undue weight to such worries and unnecessarily impede research and the development of new means of reducing the social burden of disease.

      In the short article that concludes this Part, Julian Savulescu and Peter Singer discuss a controversial example of gene editing involving two healthy embryos that were allowed to develop into children. He Jiankui, a Chinese biophysicist who has since been sentenced to jail for undertaking this work, claimed to have edited out a gene that produces a protein that permits HIV to enter cells. Savulescu and Singer argue that the experiment was unethical because the risk–benefit ratio did not justify subjecting the children to the currently unreasonable risks associated with human gene editing. They also raise concerns about likely flaws in the process of obtaining informed consent from the future parents of the embryos. But what if, in future, gene editing is possible without the risk of off‐target mutations? This paper indicates possible ethical pathways to human germline gene editing.

13 Questions about Some Uses of Genetic Engineering

       Jonathan Glover

      There is a widespread view that any project for the genetic improvement of the human race ought to be ruled out: that there are fundamental objections of principle. The aim of this discussion is to sort out some of the main objections. It will be argued that our resistance is based on a complex of different values and reasons, none of which is, when examined, adequate to rule out in principle this use of genetic engineering. The debate on human genetic engineering should become like the debate on nuclear power: one in which large possible benefits have to be weighed against big problems and the risk of great disasters. The discussion has not reached this point, partly because the techniques have not yet been developed. But it is also partly because of the blurred vision which fuses together many separate risks and doubts into a fuzzy‐outlined opposition in principle.

Avoiding the Debate about Genes and the Environment

      In discussing the question of genetic engineering, there is everything to be said for not muddling the issue up with the debate over the relative importance of genes and environment in the development of such characteristics as intelligence. One reason for avoiding that debate is that it arouses even stronger passions than genetic engineering, and so is filled with as much acrimony as argument. But, apart from this fastidiousness, there are other reasons.

The nature–nurture dispute is generally seen as an argument about the relative weight the two factors have in causing differences within the human species: ‘IQ is 80 per cent hereditary and 20 per cent environmental’ versus ‘IQ is 80 per cent environmental and 20 per cent hereditary’. No doubt there is some approximate truth of this type to be found if we consider variations within a given population at a particular time. But it is highly unlikely that there is any such statement which is simply true of human nature regardless of context. To take the extreme case, if we could iron out all environmental differences, any residual variations would be 100 per cent genetic. It is only if we make the highly artificial assumption that different groups at different times all have an identical spread of relevant environmental differences that we can expect to find statements of this kind applying to human nature in general. To say this is not to argue that studies on the question should not be conducted, or are bound to fail. It may well be possible, and useful, to find out the relative weights of the two kinds of factor for a given characteristic among a certain group at a particular time. The point is that any such conclusions lose relevance, not only when environmental differences are stretched out or compressed, but also when genetic differences are. And this last case is what we are considering.

      We can avoid this dispute because of its irrelevance. Suppose the genetic engineering proposal were to try to make people less aggressive. On a superficial view, the proposal might be shown to be unrealistic if there were evidence to show that variation in aggressiveness is hardly genetic at all: that it is 95 per cent environmental. (Let us grant, most implausibly, that such a figure turned out to be true for the whole of humanity, regardless of social context.) But all this would show is that, within our species, the distribution of genes relevant to aggression is very uniform. It would show nothing about the likely effects on aggression if we use genetic engineering to give people a different set of genes from those they now have.

      In other words, to take genetic engineering seriously, we need take no stand on the relative importance or unimportance of genetic factors in the explanation of the present range of individual differences found in people. We need only the minimal assumption that different genes could give us different characteristics. To deny that assumption you need to be the sort of person who thinks it is only living in kennels which makes dogs different from cats.