Gregor Wolbring, a biochemist who gets around in a wheelchair, is critical of entrepreneurs and scientists who champion gene therapies as miracle cures or as transformative tools of human enhancement. If everyone uses these tools to achieve the same unimaginative dreams—to grow big muscles or have blue eyes—then humanity will be stripped of character and biological diversity. While Wolbring was invited to speak at the 2015 summit in Washington, DC, travel difficulties and teaching responsibilities at the University of Calgary prevented him from attending. Airline baggage handlers often damage his wheelchair, and flight attendants often become uncomfortable when he offers to crawl to his seat. While he does not have a genetic disease, he feels a sense of kinship with other members of the disabled community. “You can understand people like me as part of human variation,” he said, “or you can see us as being impaired and eliminate us from the population.” Wolbring is concerned that CRISPR will be used to edit people like him out of existence.

Writing a short letter to Nature, the top science journal, Wolbring summarized his views: “The disability-rights community has a history of disagreement with experts (including authorities, scientists, and clinicians) over their perception of people with disabilities.” He observed that many doctors see “disability as an abnormality instead of a feature of human diversity.” Assuming that disabled people want to be “normal,” like everyone else, “can lead to flawed ‘solutions’ and disempower those affected.”

When I first spoke with Gregor Wolbring, he insisted, “CRISPR-Cas9 is nothing new.” When geneticists started celebrating this wonderful new tool for molecular biology, he said, “every biochemist was mostly just eye-rolling.” Scientists are only starting to understand how genes fit within complex biochemical interactions in living cells. Before rushing ahead with new tools, biologists should learn from the recent past. Modern chemistry has already produced profound changes to humanity. Mistakes were made that have left a lasting impact on human bodies and the environment. The biologists who are celebrating the power of CRISPR could be dangerous in their naïveté. If new precautionary laws aren't passed, he wonders, will society be able to live with their mistakes?