Of Cherries, Fudge, and Onions: Science and Its Courtroom Perversion

Abstract

DAVID W. PETERSON [*] JOHN M. CONLEY [**] I INTRODUCTION The Supreme Court's decisions in Daubert v. Merrell Dow Pharmaceuticals, Inc.[1] General Electric Co. v. Joiner,[2] and Kumho Tire Co., Ltd. v. Carmichael[3] (the "Daubert trilogy") redefine the duties of trial courts as arbiters of good scientific evidence.[4] Whereas under the venerable Frye test judges needed only to hear that the evidence was generally accepted in the relevant scientific community,[5] they are now thrust into an active "gatekeeping" role.[6] Above all, the Daubert trilogy requires courts to recognize the scientific method.[7] The legal test for reliability of scientific evidence is whether it conforms to the scientific method.[8] Courts must scrutinize purportedly scientific evidence for specific indicia of the scientific method; where these indicia are present, the evidence will be deemed reliable. [9] In other words, at least with respect to reliability, the law should accept what science should accept. [10] Although its nominal focus is on admissibility alone, the Daubert trilogy also has profound implications for causation, in particular the relationship between scientific and legal causation. The purpose of the epistemological system that we call the scientific method is to provide rules for deciding when evidence counts--when it can be relied on to support a deduction about truth or an inference about causation. [11] The ultimate standards of truth and causation employed by science and law are very different, though both standards are couched in terms of probabilities. Science focuses on the specific probability of the chance occurrence of a particular result, while the law speaks vaguely, asking whether proffered accounts of truth and causation are "more probable than not" in a civil case, or are convincing "beyond a reasonable doubt" in a criminal case. Despite these differences, the Daubert trilogy has linked the two standards inextricably, and the scientific method is the bridge. The very existence of the expert testimony controversy reflects the fact that, in many cases, a finding of scientific causation will be highly material to the question of legal causation. Indeed, in Daubert itself, a finding of legal causation could be based only on a claim of scientific causation. [12] In response to the question when purported evidence of scientific causation is sufficiently reliable to be admitted in support of legal causation, the Court answered: when it conforms to the scientific method. 13 Thus, if a claim of scientific causation appears to be based on scientific methodology, then it can be translated into evidence of legal causation. The Daubert cases assume that trial judges will be able to discern the scientific method with reasonable accuracy. Taking their duties seriously, trial judges in Daubert jurisdictions have added a new term of art to the legal lexicon--the "Daubert hearing," a voir dire examination of an expert to investigate whether his or her methods were properly scientific. [14] The resulting case law suggests that these hearings are far from perfunctory, with much attempted separation of wheat from chaff. [15] The thesis of this article, however, is that Daubert's focus on the scientific method, however rigorously applied, invites certain classes of abuses. Specifically, by moving courts from the Frye test's concrete focus on general acceptance to a more abstract inquiry, the new standard may have opened the door to evidentiary wolves in sheeps' clothing: claims that have the external manifestations of science, but in fact do violence to core tenets of the scientific method. Whereas Frye posed a fairly simple empirical question--do other experts say that this "science" is generally acceptable? [16]--Daubert asks whether the evidence has the attributes of science. [17] These attributes are supposed to be scrutinized in a sophisticated way. [18] But, as Joseph Sanders put it during the discussion at the editorial conference for this symposium, a direct if unintended effect of Daubert is that evidence that looks more scientific will more probably be deemed admissible. …