Whether a purported inconsistency in the testimony of an expert witness is an issue of credibility for the jury to resolve or a basis for judgment as a matter of law

Despite sometimes highly technical subject matter, federal courts have always trusted lay juries to resolve patent disputes, including by evaluating expert testimony. That has been the rule since the Patent Act of 1790, which th e First Congress passed and President Washington signed even before the States ratified the Sevent h Amendment and its no-reexamination mandate in 1791. And deference to juries in patent cases was also the touchstone in every regional circuit before Congress created the Federal Circuit in 1982, in a statut e that did not (and could not) change that constitutional norm. But as numerous the United States —have observed, the Federal Circuit has since claimed the authority to second-guess a jury’s evaluation of expert credibility on the basis of a cold appellate record, and overrule jury verdicts based on its own assessment of the expert testimony. The question presented is: Whether a purported inconsistency in the testimony of an expert witnes s is an issue of credibility for the jury to resolve, as every regional circuit holds, or whether it instead supplie s a basis for judgment as a matter of law, as the Federal Circuit held below and routinely holds in other cases.