From The Atlantic:

Late in 2010, Google Labs introduced something called the NGram Viewer, which allows users to search a database of millions of published works and discover how often particular words have been used from year to year. If you search for the word inquisition, you’ll get a graph showing a sharp upward climb beginning about a decade ago.

The word comes up more and more because people have been invoking it as a casual metaphor when writing about our own times—for instance, when referring to modern methods of interrogation, surveillance, torture, and censorship. The original Inquisition was initiated by the Church in the 13th century to deal with heretics and other undesirables, and continued off and on for 600 years. But it’s a mistake to think of the Inquisition as just a metaphor, or as relegated to the past. For one thing, within the Church, it has never quite ended; the office charged today with safeguarding doctrine and meting out discipline occupies the Inquisition’s old palazzo at the Vatican. More to the point, the Inquisition had all the hallmarks of a modern institution—with a bureaucracy, a memory, a procedure, a set of tools, a staff of technocrats, and an all-encompassing ideology that brooked no dissent. It was not a relic but a harbinger.

You can see this in the work of someone like Bernard Gui. Few personal details are known about the man himself, but Eco’s fictional characterization gets at something authentic. He was methodical, learned, clever, patient, and relentless—all of this can be inferred from the paper trail. Gui was a prodigious writer. Among other things, he compiled a lengthy manual for inquisitors called Practica officii inquisitionis heretice pravitatis, or “Conduct of the Inquisition Into Heretical Depravity.” The manual covers the nature and types of heresy an inquisitor might encounter and also provides advice on everything from conducting an interrogation to pronouncing a death sentence.

Gui would never have put it this way, but his aim in the Practica was to create something like a science of interrogation. He was well aware that interrogation is a transaction between two people—a high-stakes game—and that the person being interrogated, like the person asking the questions, brings an attitude and a method to the process. The accused may be wily and disputatious. Or he may seem humble and accommodating. He may feign insanity. He may resort to “sophistries, deceit, and verbal trickery.” The inquisitor, Gui advised, needed a variety of “distinct and appropriate techniques.”

Lt. Gen. John Kimmons, U.S. Army, holds up a copy of the Army Field Manual, Human Intelligence Collector Operations as he briefs reporters on the details of the manual in the Pentagon on September 6, 2006. The manual details guidelines for the interrogation of detainees in U.S. military custody.

Gui’s was not the Inquisition’s first interrogation manual, but it was one of the most influential. A generation after Gui, another Dominican, Nicholas Eymerich, produced the Directorium inquisitorum, which built on the work of his predecessor and achieved even greater renown. In our own times, the techniques of interrogation have been refined by psychologists and criminologists, by soldiers and spies. Place the medieval techniques alongside those laid out in modern handbooks, such as Human Intelligence Collector Operations, the U.S. Army interrogation manual, and the inquisitors’ practices seem very up-to-date.

“Torturer’s Apprentice”, Cullen Murphy, The Atlantic