In late November 2018, Chinese scientist Dr. He Jiankui announced at the Second International Summit on Human Genome Editing in Hong Kong that he had used CRISPR/Cas 9 gene editing on two female embryos that were brought to term through an in vitro fertilization (IVF) pregnancy. The world scientific community was ill-prepared for the announcement since the moral issues surrounding the editing of human embryos were under discussion but hardly resolved. The recommendation of the 12-member organizing committee of the 2015 International Summit on Human Gene Editing in Washington, DC, stated that it would be irresponsible to undertake any clinical use of germline editing unless and until the safety and efficacy issues were resolved and there was a broad consensus on the specific application, and that such use could proceed only under appropriate regulatory oversight. Similar recommendations were made by the National Academies of Sciences, Engineering, and Medicine. This editorial gives two reasons for genetically modifying embryos and three reasons against it.