This is not America’s first brush with cancel culture, but we can bring it to a better, quicker end if we show courage now rather than hoping it burns itself out. In 1692, a group of hysterical teenage girls in Salem, Massachusetts, began denouncing girls from rival families as witches. Accusations of witchcraft soon multiplied and spread throughout the town; some of the accused were as young as four years old. Ultimately, 200 people were tried, and dozens executed, for fictitious crimes. The court did not require evidence, as the accusations themselves were considered proof of guilt. There are obvious...