The "reasonable doubt" rule is notoriously difficult to define, and many judges and scholars have deplored the confusion it creates in the minds of jurors. Yet "reasonable doubt" is regarded as a fundamental part of our law. How can a rule of such fundamental importance be so difficult to define and understand?
The answer, this paper tries to show, lies in history. The "reasonable doubt" rule was not originally designed to serve the purpose it is asked to serve today: It was not originally designed to protect the accused. Instead, it was designed to protect the souls of the jurors against damnation. Convicting an innocent defendant was regarded, in the older Christian tradition, as a potential mortal sin. The purpose of the "reasonable doubt" instruction was to address this frightening possibility, reassuring jurors that they could convict the defendant without risking their own salvation, as long as their doubts about guilt were not "reasonable." In its original form, the rule thus had nothing to do with maintaining the rule of law in the sense that we use the phrase, and nothing like the relationship we imagine to the values of liberty. This helps explain why our law is in a state of such disquieting confusion today. We are asking the "reasonable doubt" standard to serve a function that it was not originally designed to serve, and it does its work predictably badly.
The paper offers a detailed account of the Christian moral theology of doubt, and a reinterpretation of the development of jury trial in the seventeenth and eighteenth centuries. It also includes a discussion of an important jurisprudential distinction: the distinction between proof procedures and what the paper calls "moral comfort" procedures. Without a proper comprehension of this distinction, we cannot understand the original significance of "reasonable doubt," or more broadly the structure of pre-modern law.
