The slippery slope of the human gene editing debate

The ethical debate about what is now called “human gene editing” (HGE) began sixty years ago. At the time, eugenicist scientists wanted to use new knowledge about the structure of DNA to modify humans—to perfect the human species by making us more healthy, musical, intelligent, and generally virtuous. A consensus later formed that gene editing on individuals to remove disease is acceptable, but nobody should try to change the human species. This is known as the somatic (individual) vs. germline (species) distinction, and it served as a moral limit on HGE for 50 years. A few years ago the news broke that a Chinese scientist had facilitated the creation of children who have been genetically modified so their descendants would also be modified—germline HGE. The germline limit now seems to be gone. Are there any limits left?

The HGE debate, like many bioethical debates, is set up like a slippery slope. At the top is an act universally considered morally virtuous (point A). Stepping on the slope at the top makes the act a little bit further down the slope (point B) slightly more likely because people have gotten used to A. Having arrived at B, it is more likely that the debate will allow C, even further downslope. Having reached C, it is more likely that the debate will reach the dystopian bottom of the slope that nobody at point A wanted to reach.

The classic slippery slope concern is that euthanasia for the terminally ill (point A) will slip to the severely depressed (point B), which will slip to adults who do not want to live anymore (point C), to children who do not want to live (point D), and eventually to E—for people who have outlived their social utility. For debates like this, it is not that you do not get on the slope at A, but rather that you try to stop the slipping by creating a moral distinction that serves as a barrier—to keep it from sliding down to where you do not want to go.

In the HGE debate, 50 years ago everyone got on the slope at point A, which was somatic gene therapy—healing genetic disease in existing people in a way that the changes would not pass on to descendants. The bottom of the slope in the debate, let’s call it D, is portrayed as an unequal world of genetic control of the species where people are designed for particular purposes. This has been metaphorically represented by the novel Brave New World and the movie Gattaca. People got on at A because they wanted to relieve suffering of existing people, and because they thought the somatic/germline barrier below would hold. If we stopped at germline modifications, HGE could not slide to species perfection. Now, the scientists who do this type of research are creating plans for more germline HGE. There are no agreed upon barriers between where we are now and the bottom of the slope.

If we look at the debates, at first glance there appear to be barriers. But, what sound like barriers in the debate are not actually limits but are conditions—speed bumps that have to be passed on the way down the slope. The first condition is safety—no HGE should occur unless it is safe. Of course, all agree with this, but note that this means that if Gattaca-style germline genetic control were to become safe it would be acceptable. Safety is a speed bump, not a barrier.

Others in this debate say that editing embryos is a type of reproduction, and women have an autonomous right to modify their children, in the same way they have a right to an abortion. This is also not a barrier, because people could autonomously select any modification they want, such as cognitive enhancements.

Scientists and bioethicists often say they want to limit editing to improving “health.” “Health” is of course a notoriously slippery concept, which the World Health Organization famously defined as “a state of complete physical, mental and social wellbeing and not merely the absence of disease or infirmity.” With this definition, “health” could encompass any social problem, particularly when it is the autonomous individual who will decide what “health” means to them.

It turns out that the somatic/germline distinction was the last clear barrier between the universally accepted somatic gene therapy for disease and the dystopian bottom of the slope. The somatic/germline barrier served to assure people that they could advance the moral good of somatic therapy without the risk of dystopia and reassured the public that scientists believed in limits. Scientists are moving past that barrier. For those who want to avoid the bottom, and those who want the public to support applications like somatic gene therapy, it is critical to develop some limits to our technological abilities.

Featured image via Pixabay