In his famous treatise, Wigmore compared ordinary practical decision making with adjudication, in the course of which he made the following comment regarding both: “So far as mere logic is concerned, it is perhaps questionable whether there is much importance in the doctrine of burden of proof as affecting persons in controversy.” While I have the utmost respect for the work of this giant of jurisprudence, much of the present book, if successful, will have shown just how misleading this comment can be.

A Brief Summary

My inquiry has elucidated an understanding of the burdens of proof in terms of two distinct kinds of evidential “weight.” On the one hand, an adjudicative tribunal is called on to assess weight in a sense that is comparative as between the two sides. The tribunal compares the support that the evidence gives to the claimant's case with that which the evidence gives to the opponent's case. This notion of weight I have called the “discriminatory power” of the evidence available to the tribunal, where it is understood that the evidence formally presented in court is assessed within the context of the general background information with which the tribunal legitimately approaches its task as well as the more case-specific, uncontroverted facts that are communicated to the fact-finder in numerous ways. Chapter 2 illustrated how the idea of discriminatory power can be developed. One powerful interpretive model, an adaptation of conventional decision theory, has identifiable strengths as well as some weaknesses. While it is largely agnostic about the process by which the fact-finder reaches its assessment, it does suppose that the outcome of that assessment can be captured by comparing an approximate probability or odds with a publicly stated standard. This judgment implements the law's policy regarding the allocation of the unavoidable risks of error.

On the other hand – and to a large degree independent of how one gives specific content to a theory of discriminatory power – the tribunal is called on to assess weight in a sense that is comparative only in a different way: this sense of weight is the same for each of the contending hypotheses, but it varies with the amount of evidence considered with respect to them.