A couple of years ago, Human Rights Watch launched a report arguing for a treaty ban on fully autonomous weapons, claiming military robots who target and kill human beings would violate international law. Among other arguments, the report Losing Humanity cited the Marten’s Clause of the Hague Convention, which encourages states to consider the “dictates of the public conscience” in determining whether as-yet-ungoverned activities were morally permissible among civilized nations. Intrigued by this advocacy claim, I conducted a survey in 2013 to test whether public revulsion at the idea of...