It is indeed probable that more harm and misery has been caused by men determined to use coercion to stamp out a moral evil than by men intent on doing evil.
In 2010, I worked on a Dateline NBC two-hour television special in which we replicated a number of now classic psychology experiments. In one experiment, an unsuspecting subject and a room full of confederates (i.e., actors who know the objective of the study) were asked to fill out applications to participate in a television game show. The confederates dutifully filled out their forms, even as the room gradually filled with smoke—but, remarkably, most of the subjects continued to fill out their forms too. The majority of unsuspecting participants, who had every reason to believe that the building was actually on fire, continued their task, as if burning to death was not a particular problem for them. Everyone else was calm, so they were calm. As the subjects coughed and waved the smoke away, heads bent to their trivial task, the herd instinct became ever more blazingly obvious. You could almost hear the baaa-ing. But the most dramatic experiment we replicated was Yale University professor Stanley Milgram’s famous shock experiments from the early 1960s on the nature of evil.
In a book on moral progress, it is necessary to address its obvious antithesis—moral regress—and identify which pathways lead to evil in order to mitigate them.