While urging Virginians to “love your neighbor,” Gov. Glenn Youngkin (R) also established a phone line where parents could leave “tips and observations” if teachers bring up offensive material in the classroom — specifically, teaching about race in ways that might make students uncomfortable.

But this effort to enlist parents in an anonymous campaign against teachers is fraught with peril. For centuries secret denunciations by neighbors, friends and even family have been the tools of dictatorships, used to sow fear and enforce conformity.

The European witchcraft trials of the 16th and 17th centuries exposed the power and peril of such secret accusations. Trials for witchcraft peaked as early modern states, in collaboration with church authorities, extended and increased their power over their subjects. While difficult to estimate, most scholars agree that somewhere between 100,000 and 200,000 individuals (the majority of them women) were tried for witchcraft during those years. Of those, between 40,000 and 60,000 were executed.

A number of factors fueled the effort to ferret out witches during these years. The political and psychological tensions that resulted from the Protestant Reformation and subsequent wars of religion certainly played a role. So too did demographic changes that led to increasing numbers of unmarried women, the most common victim of witchcraft accusations. Witches were a convenient scapegoat for any number of social ills.

However, legal changes connected to the spread of Roman law throughout Europe also played a role. These shifts had begun centuries earlier, when the growth of higher education in the 11th and 12th centuries led to a revival in the formal study of Roman law in newly created universities, where scholars appreciated the law’s logic and rigor. For rulers looking to grow their power, implementing this legal code provided more authority since a maxim of Roman law was that “the king’s will has the force of law.”

The adoption of Roman law also involved a shift from an accusatorial legal procedure to an inquisitorial procedure, pioneered by the Catholic Church but eventually adopted by secular authorities as well. Under the former, suspects knew what the accusations were and who was making them, and they could sue the accuser if the charges were not proved. Under an inquisitorial procedure, legal authorities brought the case and the accusers remained hidden. Secrecy was an essential element of these newly “officialized” and “rationalized” inquisitorial procedures, as was torture to obtain the confessions that would corroborate the secret accusations.