After reading Savulescu and colleagues,1 one ought to be in no doubt that human heritable genome editing is a ‘moral imperative’: to cure disease, reduce inequalities, improve public health and protect future generations. They make this argument repeatedly and in no uncertain terms. Yet are they right to do so? I am certainly not against developing HGE or exploring its possibilities. Instead, I aim to sound a cautionary note in relation to claims about its technological potential and how we frame (...) arguments on this basis. The ‘moral imperative’ argument has been made many times, since well before the advent of genome editing, by the present authors and others. It generally rests on a number of preconditions, implicit or explicit: that HGE will be safe, effective, cost-efficient and equitably available. Now, many bioethicists would take no issue with, indeed have supported,5 the proposition that, once all of these conditions are satisfied, HGE is something we have good moral reasons to pursue. At this pivotal moment for global science, ethics and governance, however, we need equally to be concerned with the technology’s immediate future trajectory: whether and how we can reach the point of satisfying these conditions. In this context, the MIA is something of a distraction; at worst, it may even be corrosive and damaging. Consider first the argument from evolutionary fitness, that HGE is morally required to counteract the supposed ‘genetic deterioration’ produced by medically enabled ‘survival of the weak’, that makes …. (shrink)