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Villanova Law Review

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scientific evidence, consensus rule, expert witness, factfinding, Daubert standard


Evidence | Law | Science and Technology Law


A fundamental conceptual problem has long dogged discussions about scientific and other expert evidence in the courtroom. In American law, the problem was most famously posed by Judge Learned Hand, who asked: "[H]ow can the jury judge between two statements each founded upon an experience confessedly foreign in kind to their own? It is just because they are incompetent for such a task that the expert is necessary at all." This puzzle, sometimes known as the "expert paradox," is quite general. It applies not only to the jury as factfinder, but also to the judge as gate- keeper under the "Daubert v. Merrell Dow Pharmaceuticals, Inc." regime and Federal Rule of Evidence 702. It also applies when there is no jury at all, whether in a bench trial, administrative proceeding, or civil law jurisdiction. When it comes to scientific and other specialized knowledge, legal actors are inevitably non-experts. And if legal actors are faced with the so- called "battle of the experts," how are they to decide between the warring experts? After all, to quote Judge Hand again, "[i]t is just because they are incompetent for such a task that the expert is necessary at all." As one of us has previously argued, because of this epistemic competency problem, the Daubert approach to expert evidence is a mistake. The solution to the problem of expert evidence is not judicial gatekeeping, but rather to change the substantive question asked of legal actors.



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