Idealizing science and demonizing experts: An intellectual history of expert evidence

This Article, published in a symposium issue focusing on science and expertise, traces the early reception of the modern expert witness. It describes in some detail the widespread frustrations with expert witnesses in court in the closing decades of the nineteenth century, focusing in particular on the two most vociferous critiques: that experts too often became partisans, mere mouthpieces for the party that hired them; and that expert testimony was so frequently contradictory that it confused and perplexed, rather than enlightened, the lay jurors who heard it. The Article argues that these criticisms can only be properly understood by recognizing two important aspects of how expert evidence was being wielded and understood in this period. First, it is important to recognize that even amidst the rampant complaints by the bench, bar, and experts themselves, about the content and methods of expert testimony, the actual use of expert evidence was simultaneously increasing. Second, I argue that a key source of the dissatisfaction with expert testimony was a disjunction between a set of idealized expectations for scientific evidence and the practical realities of its use in the courtroom. It was precisely because of what science was thought to be able to offer to the process of legal decisionmaking, that the spectacle of warring experts provoked such frustration and anger. Science ought to have been able to offer proof more objective, more certain, and more neutral than that of the lay eyewitness, or so believed scientists and legal commentators alike. When it failed to do so, this failure was frequently attributed to partisan excess or the problems of adversarialism, rather than recognized as being, at least in significant part, the result of unrealistic expectations for science itself. In the conclusion, I suggest that this idealized conception of science lingers with us today as well, and continues to influence how we understand and critique expert evidence in court.