It is (or should be) well understood in American society that the Government must prove you guilty beyond a reasonable doubt before taking away your liberty or your life—the highest standard of proof available in our criminal justice system. But what if I told you this standard has absolutely nothing to do with protecting those accused of crime? What if I told you the reasonable doubt standard is an ancient theological concept established to increase, not reduce, convictions?

In an article for the ABA’s TYL magazine a few years ago, the author laid out “A Plan for Closing Argument” that is pretty consistent with what is commonly taught. In it, the author defines the burden of proof in criminal cases as the requirement the Government prove every element of the offense “[b]eyond and to the exclusion of each and every reasonable doubt.” He goes on to describe this requirement as “a tall order.” He then laid out the analogy he used at trial to explain exactly how hard it is for the Government to meet this burden:

In jury selection, I used a bowling analogy to explain the state’s burden of proof. I asked anyone if they’ve been bowling, and I asked how to bowl a strike. I asked if the bowler has to knock down all the pins. Of course, the answer is yes. I asked them if a person can bowl a strike without knocking all the pins down. Of course, the answer is no. I told them that the state had a similar job; they had to bowl a strike and eliminate all reasonable doubt that the defendant is innocent. If any pins, or doubts that are reasonable, are left standing, the state did not do its job. In closing, tell them there are three pins left standing, and when there are reasonable doubts that a defendant committed a crime, the law demands an acquittal. Tell them that you only need one reasonable doubt and the law requires a not guilty verdict, but you’ve given them three because there is that much doubt in this case. Tell them this is in the jury instructions and you should print a copy of the instruction on giant paper and show it to them.

While the analogy may vary, every criminal defense attorney in America a similar one. But in his book, The Origins of Reasonable Doubt, Professor James Q. Whitman challenges our understanding of this standard of proof through detailed, yet accessible, historical research.

The historical record demonstrates that theologians crafted this concept out of concern for the souls of jurors, not the accused. In earlier times, convicting a person of a crime while harboring any doubt as to his innocence was a mortal sin. So, as one can imagine, acquittal rates were high. So, theologians found a “third way.” High rates of acquittal were unacceptable, particularly in cases with relatively strong evidence. But so long as jurors harbored at least some doubt, these results weren’t likely to change.

Thus, the reasonable doubt standard became the “third way” between setting free criminals or eternal damnation. Doubt became ok. So long as that doubt was “unreasonable,” the juror felt safe to convict without damning his soul. In what may be a shock to prosecutors and defense attorneys alike, the origin of the reasonable doubt standard was to make it easier to convict, not harder.

The Christian tradition has faded from modern society, but the reasonable doubt standard remains. I am certainly not advocating for a return to this mindset, but it is interesting to understand where our legal traditions come from, and why this one tends to be so hard to explain.

This is a fascinating book and well worth the read. Professor Whitman also discusses the evolution from trial by ordeal (God as witness), to judge as factfinder, to the jury (neighbor as witness). I highly recommend this book to anyone interested in gaining a better understanding of the foundations of our system of law.