Abstract
In many respects [the scientific expert seems to be a positive annoyance to lawyers, and even to judges at times, a sort of intractable, incompatible, inharmonious factor, disturbing the otherwise smooth current of legal procedure; too important or necessary to be ruled out, too intelligent and disciplined mentally to yield without reason to ordinary rules and regulations of the court, ... and, at the same time[,] possessing an undoubted influence with the jury, that it is difficult to restrict by the established rules and maxims of legal procedure. (1) It is often said, with good cause, that ... the goal of a trial and the goal of science are ... at odds.... [A]s a general rule.... courts don't do science very well. (2) I GETTING STARTED There was not a lot to be said for the miserable weeks after Hurricanes Katrina and Wilma--except, in retrospect, that all those hours spent sweating in the dark prompted some vivid thoughts about what life must have been like before electric light and power were available at the /lick of a switch, and renewed my appreciation of the countless ways in which science now permeates just about every aspect of modern life. "Every aspect of modern life" including, of course, the legal system. Legal proceedings now often rely significantly on scientific testimony, and scientific advisors contribute significantly to regulatory decisionmaking. (3) Moreover, the law regulates potentially hazardous scientific research; (4) it may get involved when fraud is alleged in scientific work funded by government grants; (5) and it may be called on to resolve disputes between scientific interests and interests of other kinds, for example, in "cultural heritage" cases such as the tussle over the fate of the 9,000-year-old skeleton of Kennewick Man, (6) or in constitutional cases over high-school biology teaching. (7) I shall confine myself here largely to scientific testimony in litigation; which, from the beginning, has prompted complaints both about the venality and dishonesty of scientific witnesses and about the scientific ignorance and credulity of jurors, attorneys, and judges. But some of what I have to say will also be relevant to the other contexts in which science interacts with the law; for the core of my argument will be that there are deep tensions between the goals and values of the scientific enterprise and the culture of the law, especially the culture of the U.S. legal system: (8) between the investigative character of science and the adversarial culture of our legal system; between the scientific search for general principles and the legal focus on particular cases; between the pervasive fallibilism of the sciences--its openness to revision in the light of new evidence--and the concern of the law for prompt and final resolutions; between the scientific push for innovation and the legal system's concern for precedent; between the informal, problem-oriented pragmatism of scientific investigation and the reliance of the legal system on formal rules and procedures; and between the essentially theoretical aspirations of science and the legal system's inevitable orientation to policy. The first step will be to sketch how the legal system began to use scientific experts, and how it has tried to accommodate their testimony to its own culture; the next, to understand what it is about the nature of science and the culture of law that makes the scientific expert, as Dr. Himes says, "a sort of intractable, incompatible, inharmonious factor, disturbing the smooth current of legal procedure"; then to illustrate how the tensions between science and the law reveal themselves in practice; and finally to comment, very briefly, on some efforts to alleviate the tensions. II THE SCIENTIFIC WITNESS Of course, there haven't always been scientific witnesses; in fact, there haven't always been witnesses. In early medieval times, courts relied on tests by oath, ordeal, and sometimes (though in England, apparently, only rarely) by combat. …