In Heredity and Hope, Ruth Schwartz Cowan, professor of history and sociology of science at the University of Pennsylvania, has written an informative and readable history of genetic screening. She walks the reader through the complex and sometimes controversial practices that have created the new field of genetic medicine. As for the claim in the subtitle, The Case for Genetic Screening, well, on that score: caveat lector!

First, the historical account. In the first half of her book, the author recounts for the lay reader the story of the beginnings of genetic testing (for individuals) and screening (for groups) as they developed out of, and differentiated themselves from, the morally opprobrious eugenics movements of the first half of the twentieth century. The new forms of screening—prenatal, newborn, and carrier testing—have, as she sees it, goals that are significantly different from those of the eugenics movement. She points out (fairly convincingly for this nonhistorian) that the missions of eugenics and genetic screening are at cross-purposes with each other: eugenicists wanted to purify the gene pool by eliminating undesirable genetic traits—mainly through sterilization—while the techniques of genetic medicine have a pronatalist purpose in helping parents, particularly those who carry recessive genes for terrible diseases, to reduce suffering and have healthy babies. The second half of the book recounts four extended case studies: phenylketonuria (PKU), Tay Sachs disease, sickle-cell anemia, and beta-thalassemia.

Although Heredity and Hope is written in the somewhat pedestrian style of most social science, the developing story, like all good yarns, has a certain drama to it. It has its share of heroes and villains and a troublesome chorus. The villains, eugenicists such as the Englishman Francis Galton, the American Hermann Muller, the Russian Alexsandr Serebrovsky, and the infamous Nazis, are given short shrift, which is what they deserve. Cowan’s heroes are the scientists and physicians—people like James Neel, who was among the first to see the therapeutic possibilities of Mendel’s genetics; Fritz Fuchs, who developed the procedure of amniocentesis; Robert Guthrie, who developed the test for PKU; and others who successfully combined the developing science of genetics with the practice of obstetrics. There are dramatic victories in the battles against PKU and Tay Sachs and the stinging failure of the sickle-cell story. Cowan’s paradigmatic case is the lesser-known story of beta-thalassemia disease on the island of Cyprus. There the author spent time studying how both the Turkish and Cypriot communities have virtually eliminated this genetic and (if untreated) fatal blood disorder through what amounts to a mandatory screening policy. It is her experience in Cyprus that changed Cowan’s views and led to her unabashed support of genetic screening.

The book’s dramatic tension is provided by what one might call the oppositional chorus. The author is trying to address four very different groups that reject the new medical genetics: some left-wing intellectuals who object to the biological determinism they see as underpinning genetic screening; those feminists who object to the medicalization of pregnancy and birth; disability-group advocates who fear genetic screening will have a negative effect on society’s commitment to the physically disadvantaged; and prolife groups who obviously argue against the preferred method of therapy for genetically screened diseases—abortion.

Cowan, herself a liberal feminist, is sympathetic with some of these concerns. But she believes the choral dissidents are all guilty of some fallacious historical assumptions about genetic medicine. Most commonly, they commit the genetic fallacy of confusing the origins of genetic medicine in eugenics with today’s therapeutic aims. She hopes that by pointing to historical facts she can persuade the opposition—as she was persuaded—of the benign intent of genetic screening.

Her strategy of appealing to therapeutic history is of limited value. Each of the four groups opposed to genetic screening might well grant Cowan her historical points and still not agree with her moral argument in favor of the practice. In fact, Cowan seems to be answering their failed argument with a fallacy of her own: the mistake of converting an is or was into an ought—of converting facts by themselves into a moral argument. For example, Cowan claims the superiority of history over bioethics because the former “examines the particular, not the universal.” In the next sentence she says such an approach allows the social historian to balance interests so that “no set of interests is allowed to dominate over the others.” Now, where in history’s name did that universal principle come from, and how would it be particularly justified?

Her claim that she is making “an ethical argument using historical tools” reminded me of Michael Walzer’s Just and Unjust Wars: A Moral Argument with Historical Illustrations. Unfortunately, Heredity and Hope does not meet that illustrious (and illustrative) standard. It offers a historical account with a tacked-on, cursory treatment of the ethical argument advertised in its own subtitle. The stabs at moral argumentation are at best eclectic, at worst muddled. There is a maddeningly ad hoc utilization of moral thinking, one that appeals to utilitarian considerations when those seem hospitable and to the principle of individual autonomy when that seems more useful. Cowan does offer a measure of common sense and some sociological insights into the ethical commitments of various groups, but they do not add up to a convincing argument. Simply pointing out, for example, that some Cypriot Orthodox clergy tended to look the other way when couples decided to abort fetuses afflicted with beta-thalassemia does not help us judge, as Cowan thinks it does, the morality of aborting diseased fetuses. She completely rejects traditional moral and religious guideposts and believes that simply laying out the historical facts will lead to clear, distinct, and incontrovertible insights about the good of genetic screening. She concludes by blithely rejecting any caution and offers her ringing endorsement of genetic testing and screening “without guilt, without ambivalence, and without apology.”

But caution may well be the order of the day. One does not have to be on the extreme right or left to feel some ambivalence about the whole project of genetic medicine. Her opponents’ arguments, for example, about biological determinism and the overmedicalization of pregnancy are not sufficiently countered. Nor, it needs be said, does Cowan adequately address the issue of abortion. (The only critic of abortion addressed in the text is a right-wing Christian blogger.) Any work that purports to be an argument rather than just a history should analyze the broader context of a risk-averse medical culture that encourages parents to use genetic testing in their quest for the perfect baby. Uncomfortable questions are rarely posed and even more rarely addressed. What, for example, is a “normal” fetus? What constitutes disease? Are gender and homosexuality diseases? Should we screen if we cannot treat? Has screening created a disincentive to seek cures? Even Cowan’s strongest claim, that genetic medicine is not eugenics, is not quite obvious. After all, abortion after genetic testing could serve the same purpose as sterilization did in earlier eugenic programs. Finally, the practical problem of genetic discrimination on the part of health-insurance companies needs to be addressed by any thoughtful advocate of genetic screening. If one consults the ethical literature on this issue—mainly the product of those universalizing bioethicists—one will find more nuanced accounts, such as Adam Schulman’s cautious report for the Presidential Council on Bioethics or Michael Sandel’s The Case Against Perfection.

Imagine a scenario—in the not-too-distant future—made possible by prenatal testing. A baby’s full genomic profile is created at birth and entered into a biobank that contains information interlinking the baby’s medical history with the histories of thousands of others. Will that information represent the next great medical breakthrough or a further step into the Huxley Brave New World? If readers look to Heredity and Hope for history, they will find it instructive. But for a serious consideration of the critical difference between what we can do and what we ought to do, readers must look elsewhere.

Related: Paul Lauritzen reviews Michael Sandel's The Case Against Perfection
Andrew Lustig reviews Ronald M. Green's Babies by Design