An Excess of Discretion? 'Thayer's Triumph' and the Uncodified Exclusion of Speculative Evidence
9 Pages Posted: 7 Jul 2016 Last revised: 17 Apr 2017
Date Written: July 6, 2016
Modern evidence law is based on codes that expressly deny courts discretion to create common law rules categorically excluding evidence. And yet a commonly applied and important exclusion rule in evidence law appears to be uncodified: the law of evidence includes a broad rule against speculation. Yet the concept of speculation is not adequately explained or theorized. This essay offers a preliminary effort at gaining a more thorough understanding of what speculation is, how it tracks with the rules of evidence, and when it should and should not result in exclusions of evidence. The essay argues that speculation is best understood as the thought process of substituting dubious generalizations or factual hypotheses for facts that are missing or unsupported by evidence. Claims that evidence is speculative should be analyzed as a foundation problem under one or more of the codified foundation rules. Moreover, it should be recognized that not all speculation by the trier of fact is impermissible.
Keywords: Evidence, Federal Rules of Evidence, FRE, 701, 901, 104, 602, exclusion, relevance, speculative, speculation, conjecture, guessing, foundation, opinion, state of mind, relevance, conditional relevance
JEL Classification: K41: Litigation Process
Suggested Citation: Suggested Citation