How the Trial by Fire Was a Surprisingly Accurate Test of Guilt

Back before we had DNA evidence, fingerprint databases, police lineups, or even presumption of innocence, trials were performed in the church. The trial by fire — or, more accurately, the "trial by ordeal" — was simple: Put your hand in boiling water (or hold a red-hot iron, or be thrown in the lake). If you were innocent, God would leave you unscathed. If you were guilty, you suffered the consequences. As barbaric as it sounds, George Mason University economics professor Peter T. Leeson points out that it probably was a pretty accurate test of guilt at the time. Here's why.

Innocent Until Proven Maimed

Say your neighbor accuses you of stealing his cow. The court orders you to undergo the hot-water ordeal, where the priest boils a cauldron of water and tosses a ring into the bottom for you to retrieve by hand. You believe in judicium Dei, the idea that a priest can follow the appropriate rituals to call on God to perform a miracle that protects your arm from the boiling water if you're innocent.

If you undergo the ordeal and God says you're guilty, not only will you have a terribly burned arm, but you'll have to pay a large fine as well. If you undergo the ordeal and God says you're innocent, you're unscathed and pay nothing. There's also a third option: Admit you stole the cow, skip the ordeal entirely, and pay a reduced fine. What will you do?

Say you're guilty. You know, God knows, the cow knows. If you undergo the ordeal, you expect to have a terribly burnt arm and end up paying a huge fine. But if you confess, your arm is left intact and you get a discount on the fine. For the guilty, then, confessing was the very best option.

But what if you're innocent? The cow wandered off, and you don't like milk anyway. You believe God knows all of that and will save your arm from the boiling water, leaving you with no fine to pay. For the innocent, undergoing the ordeal was the best option.

Therefore the ordeal doesn't even matter. It's set up so the guilty will confess and the innocent won't, thereby telling the court everything they need to know. Of course, there's one little problem: The innocent person still needs to undergo the ordeal, since, without the threat of boiling water, the guilty would never confess. What's a priest to do?

Hot Stuff

The trick to leaving the innocent with unburned flesh came down to the "instruction manual" that laid out the way the rituals should unfold. In short, it gave the priest plenty of chances to "fix" the verdict.

For the hot-iron ordeal, where the accused person carried a piece of burning iron for nine steps, it commanded that no one except the priest and the accused could be in the church before the coals were ready, that communion had to take place after the fire was lit and before the ordeal began, and that the observers all had to stay along the church walls, which were usually a good distance from the action.

From the very beginning, the priest could prep the coals in a way that left the iron at a moderate temperature and could draw out the communion prayer to give the fire time to die down. The same went for the hot-water ordeal. Even the cold-water ordeal could be fixed. In that ordeal, a person was bound in rope and tossed into the water, then sank if they were innocent and floated if they were guilty. More often than not, that ordeal was reserved for younger suspects with a small amount of body fat, since they were more likely to sink.

But doesn't this rely on the suspects being true believers and the priests being skeptics? It doesn't, and here's why. As Leeson writes in a 2012 paper published in the Journal of Law and Economics, "it is important to point out that priestly manipulation of ordeals is not incompatible with priestly faith [...] priests may have believed that they were acting in the person of Christ — that is, that God was guiding them — when they manipulated ordeals."

And as for the accused, the priests had safeguards in place to avoid any issues with religious skeptics — even if it wasn't exactly ethical. They simply made sure to keep an equal balance of guilty confessors and innocent people that underwent the ordeal. If too many people were volunteering for the ordeal, they knew they weren't convincing, and they burned a few hands to right the balance. If not enough people were volunteering, they judged a few more to be innocent. While this sounds like it might undercut the entire point of the ordeal, Leeson stresses that the way things were set up at the time was usually enough to turn most skeptics into full-on believers in the powers of God to judge the innocent and punish the guilty.

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For more fascinating explanations of bizarre traditions, read Peter T. Leeson's latest book, "WTF?!: An Economic Tour of the Weird." We handpick reading recommendations we think you may like. If you choose to make a purchase, Curiosity will get a share of the sale.

Written by Ashley Hamer November 29, 2017

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