Peter Leeson on Why Trial-by-Fire Wasn’t Barbaric and Why Pirates Were Democratic - Freakonomics
""LEESON: For about 400 years between the ninth century and the early 13th, the most sophisticated legal systems in Europe conducted physical tests in criminal cases to determine the guilt or innocence of accused suspects. In the classic medieval judicial ordeal, as these things were called, the priest or the cleric who was overseeing the trial boiled a pot of water into which he threw a stone or ring. He then asked the criminal defendant to plunge his arm into the boiling water and to pluck the object out. After that, the priest would wrap the defendant’s hand. And then, they would revisit it — the whole court would — three days later. If the arm showed evidence of having been burned very badly, that was considered evidence that God was giving to the court that the defendant was in fact guilty of the crime, in which case the defendant would then face the secular punishment, the fine or imprisonment, so to speak — although they didn’t typically use prison in the Middle Ages. If the defendant’s arm didn’t show evidence of having been burned, that was considered evidence that the defendant was innocent. God had performed a miracle and he would be let go.
There was another type of hot ordeal that was popular at the time, which was the hot iron ordeal. Instead of the defendant being asked to plunge his arm into boiling water, he was asked to carry a burning-hot iron a stipulated number of paces. The number of paces that he was supposed to walk depended upon the severity of the crime... We have 308 cases in which criminal defendants were ordered to undergo the ordeal. And it turns out that in a hundred of those cases, the criminal defendant never actually ended up undergoing the ordeal. He declined, which means he probably either confessed or he settled with his accuser, a sort of medieval version of a plea bargain. In 208 of those cases, however, the criminal defendant actually ended up carrying the supposedly red-hot burning iron. But in about two-thirds of those cases, the defendant had his arm unscathed.
LEVITT: So, I guess one possibility is that God directly intervened on behalf of the innocents but I suspect you think that there might be an alternative explanation to that.
LEESON: Yes, that’s one possibility, but I think a probably stronger possibility is that priests intervened to make sure that the red-hot burning iron wasn’t in fact red-hot, or that the boiling water for which we have similar evidence, wasn’t, in fact, boiling.
LEVITT: These are public settings. Aren’t people watching? How does the cleric rig this?
LEESON: It turns out that if you look at the instructions that priests were supposed to follow, what you see is ample opportunity for the priest to engage in chicanery. It’s almost like the instructions were directing the priest about how he could engage in ordeal rigging, in fraud, in a way, to trick the potential bystanders. Prior to the potential observers of the ordeal entering the church, the priest and the defendant were supposed to be alone praying together ostensibly inside the church when the ordeal fire was being made. And if you’ve ever made a fire before, you know that you can make fires very hot or only moderately hot. The fact that the priest and the defendant together were inside making the ordeal fire before anybody was there to watch it gave them plenty of opportunity to turn down the dial on the stove, so to speak, in order to make sure that the fire itself wouldn’t be so hot. Another interesting feature of ordeal instructions is that they direct the priest — after the defendant has plunged his arm into the boiling water or carried the burning iron — to sprinkle holy water in the name of God over his hand. In the hands of a manipulative priest, sprinkling could easily become dousing, helping to significantly offset any remaining heat.
LEVITT: This gives a pretty low appraisal of priests. I mean, these folks are representing God. And yet, you’re describing them as manipulative misleading conjurers.
LEESON: Maybe a little bit. But at the same time that medieval judicial ordeals were being used throughout Europe, there was developing in Christendom, in Catholicism, the doctrine of in persona Christi, which for the Catholics out there, is the idea that God works through the priest, that the priest is God’s worldly hands through which God is going to interact with the worldly environment around him. This is partly the doctrine that is responsible for the idea that the priest can trans-substantiate, that God working through their hands are able to alter the host and the wine into the body and blood of Christ. Priests, when conducting ordeals during this period, could have very easily believed that they were simply God’s instruments on earth, that God was working through them when they were tampering with the fire or switching the iron and so on.
LEVITT: What we haven’t really talked about explicitly is the economics behind this. And your contention is that this mechanism is an incredibly thoughtful, effective, game-theoretic way of getting to the truth in these really tough cases. Could you lay that out for people?
LEESON: I think the key to understanding the economic logic behind medieval judicial ordeals is putting yourself into the shoes of a medieval criminal defendant. Part of doing that is understanding what the beliefs of medieval citizens were during that period. According to a popular superstition of the era, which was known as Judicium Dei or the Judgment of God, God is omniscient and omnipotent, which means that a criminal defendant, while he has what we would call private information about his guilt or innocence — so, he knows the truth of the matter about whether he actually committed the crime — that information isn’t private from God who knows the state of the soul of the criminal defendant. So, conditional on a criminal defendant thinking in this way, he imagines that if he undergoes the ordeal and he’s guilty, God will let the boiling water burn his arm, which means that the criminal defendant expects the ordeal to find him guilty and to have his arm boiled to rags, to boot. It’s better for him if he simply confesses, at least he doesn’t have to plunge his arm into boiling water.
Now suppose that the criminal defendant is innocent. Well, he expects that when he plunges his arm into the boiling water, God will perform a miracle to make sure that the water doesn’t boil him. In consequence, he expects to be exonerated. For him, undergoing the ordeal is not a bad decision at all. This basic idea suggests a kind of sorting that accused criminal defendants, when confronted with the specter of the ordeal, perform amongst themselves, a kind of self-revealing mechanism... My theory predicts that priests are overwhelmingly going to try and exonerate the people who undergo ordeals, because they know that those people’s willingness to undergo ordeals means that those people are probably innocent. Skeptics pose a problem for these faith-based institutions — these faith-based incentives, essentially. If we think about things from the perspective of a non-believer what happens? So, as you suggested, he might try and take advantage of the system by going and committing more crimes. But that means that he’s going to wind up being in front of the priest more often who, seeing him repeatedly, is likely to figure out that, “Hey, this guy is not a believer.” The priest then has an incentive to burn the guy...
LEVITT: Now, there are some interesting parallels between ordeals and modern lie detector tests, I think. Do you know much about lie detector tests?
LEESON: Yeah, they’re bullsh*t.
LEVITT: But people believe that they work. And isn’t it, in many ways, very much like the mechanism underlying ordeals?
LEESON: I think it’s the very same mechanism. The reason that most courts do not permit evidence from a polygraph, from a lie detector test, is that scientifically, they’re bogus. There’s no way to physiologically measure whether or not someone is lying or telling the truth or to detect whether they’re lying or telling the truth. But it turns out that just like ordeals, as long as people believe that they work, then there can in fact be an important use for them in our criminal justice system. Which is why I think that the F.B.I. uses lie detector tests. The military uses lie detector tests. The C.I.A. uses lie detector tests. Private companies use lie detector tests sometimes when they’re hiring employees. The important feature of this is that the people taking the tests think that they’re legit, even though the tests we know, scientifically, are not. That makes the person who has less to hide more willing to take the test than the person who has something to hide or who is likely to lie. And so, there is this self-revealing process that is really exactly the same logic that underlied medieval judicial ordeals."
