Modern observers have roundly condemned ordeals for being cruel and arbitrary. Ordeals seem to reflect everything that was wrong with the Dark Ages. They’re an icon of medieval barbarism and backwardness.
But a closer look suggests something very different: The ordeal system worked surprisingly well. It accurately determined who was guilty and who was innocent, sorting genuine criminals from those who had been wrongly accused. Stranger still, the ordeal system suggests that pervasive superstition can be good for society. Medieval legal systems leveraged citizens’ superstitious beliefs through ordeals, making it possible to secure criminal justice where it would have otherwise been impossible to do so. Some superstitions, at least, may evolve and persist for a good reason: They help us accomplish goals we couldn’t otherwise accomplish, or accomplish them more cheaply.
The system of trial by ordeal was undermined by the Church:
In the early 13th century, Pope Innocent III spearheaded a damning denunciation of ordeals on the grounds that ordeals were antithetical to Christian doctrine. His edict banned priests from further involvement with them. The Church’s condemnation of ordeals seriously undermined the superstition on which ordeals relied. If ordeals were antithetical to Christianity, how could God reveal defendants’ guilt or innocence through trials of fire and water?I am not surprised that an economist wrote this because behavioral economics emphasizes the placebo effect, or power of expectations to shape our perceptions the world. However, Leesen is engaging in speculation. We do not know how effective trial by ordeal was and there is no way to find out. We also do not know how effective our current criminal justice system is and there is no way to find out. What percentage of those who are found guilty are actually innocent? How many people who are guilty are never punished? No one knows. It is quite possible that trial by ordeal was a more effective system of justice than our system. And like the system of trial by ordeal, our system depends on confidence, the belief of citizens that the system works. If people lose confidence in our system, it too will become less effective.
Leesen seems to be too careless with the word "superstition." Is belief in God superstition? If we want to use the term that loosely, then there are a great many things that are superstitious, including most or all of what we believe.
Update: One the difficulty of computing the number of innocents who have been convicted, see here.