David B Resnik, Holly B Steinkraus and Pamela J Langer, Austin, Texas, R G Landes Company, 1999, 189 pages, US$99.00 (hb).

This book provides a worthwhile and challenging introduction to scientific and moral issues in germline gene therapy. It contains two parts, dealing with scientific and moral issues respectively. In the first, scientific part, a chapter on what the alternatives to germline therapy are is helpful, especially in pointing out that many of the goals one might want to achieve by using germline therapy may be achieved, at a slighter risk, by using non-genetic technologies such as selective embryo implantation and selective abortion. However, the authors argue that germline therapy may be an option in certain cases in which these alternatives are not viable (page 72).

In the second part of the book, moral and political issues in germline therapy are discussed, such as the distinction between therapy and enhancement, potential benefits and harms, rights and responsibilities, justice, our concept of humanness, and public policy issues.

The authors present an argument from parental rights to the effect that parents have a right to use germline therapy (page 117). This right, however, may be restricted in order to prevent harm to others, such as the children who will result from such therapy. The authors conclude that, since germline therapy would not be in the best interest of children (or further generations) at this point in time (due to various technical difficulties and uncertainties), it would be irresponsible to perform it, although this situation may well change in the future (page 119).

Under what circumstances, however, may we say that a child has been harmed by germline therapy? If a particular child will come into existence whether or not germline therapy is performed, then, sometimes, it may be harmed by having (had) the therapy performed (if, for example, the therapy accidentally causes it to develop cancer); it may be worse off than it would be had the therapy not been performed. But typically, the numerically same child will not come into existence whether or not the therapy is performed (perhaps, if the therapy is not performed, no child is produced, or perhaps the parents do not opt for IVF, or perhaps, if they do, a different embryo is implanted). In such cases, then, it seems that a child is only harmed by germline therapy if its life is worth not living. And arguably, this will not be the case very often.

However, the authors prevent themselves from claiming that a child who would not have come into existence, had germline therapy not been provided, can be harmed by this therapy, because they take existence and non-existence to be evaluatively incomparable (page122). So it seems that, according to them germline therapy can only harm a child if it would exist whether or not the therapy were performed, and be worse off if it were performed. But this does not seem to restrict parental rights much.

In an illuminating chapter on justice, the authors argue that germline therapy may affect human equality. We can imagine a society in which the people who are able to pay, provide genetic enhancements for their children, who are then (further) advantaged as compared to children whose parents are not able to pay. Germline therapy may affect the range of opportunities a person has and so may affect (lessen) equality of opportunity. While such consequences could be avoided if genetic enhancements could be effectively forbidden, the authors believe it is both unrealistic and wasteful to forbid enhancements. Instead, they suggest that we should allow genetic enhancements within a genetically “normal” range (page 135). I think that this suggestion has some plausibility, but I should like to make two comments. Firstly, even within the boundaries of what is genetically normal, germline enhancements may promote inequality of opportunity. And secondly, the authors reject a ban on genetic enhancements, in part because they believe it is unrealistic, since governments and private citizens have strong interests in such enhancements. But they provide no reason to believe that a ban on enhancements beyond what is genetically normal would be invulnerable to such pressure.

After the chapter on justice comes a chapter on how germline therapy may affect our humanness. Amongst other things, the authors discuss–and reject–the view that germline therapy may be wrong because it is unnatural. So, while there are some uses of germline therapy that are unacceptable, this is not because they are unnatural, but rather because they harm or demean people.