Science at the Bar
Laws of Men and Laws of Nature: The History of Scientific Expert
Testimony in England and America. Tal Golan. x + 325 pp.
Harvard University Press, 2004. $49.95.
Science and law remain uneasy bedfellows. In the last decade, the
Supreme Court has three times issued important rulings on how trial
courts ought to evaluate expert evidence, but these cases have
generated as many questions as they have answered. Lawyers, judges
and experts continue to express a set of related anxieties: that
credulous juries may naively succumb to "junk science"
proffered by opportunistic experts; that both judges and juries,
lacking specialized scientific training, may be unable adequately to
evaluate complex scientific and technical information; that
adversarial processes and scientific knowledge are fundamentally
mismatched. As Tal Golan shows in his engaging history of expert
evidence in the Anglo-American courtroom, none of these frustrations
is of recent vintage, and in fact, complaints about expert testimony
are nearly as old as expert testimony itself.
Laws of Men and Laws of Nature is both well written and
wide-ranging, traveling from 18th-century England to early
20th-century America, from patent law to microscopy to experimental
psychology. The book is not long (264 pages, plus notes), and it is,
inevitably, selective. Golan does not explain how he chose what to
include and what to omit. He leaves the reader curious about some
subjects—chemical tests for poison identification receive only
a few pages, for example, and the early forensic sciences, such as
fingerprinting and handwriting identification, are entirely absent.
Nonetheless, the book is an extremely able, much-needed account of
the tangled, troubled connections between the world of law and the
world of science.
In style, this is a straightforward narrative history. Although the
footnotes reveal the range and extent of Golan's research, there is
no historiographical discussion to speak of, either in the text or
in the footnotes. Golan's narrative is consistent with recent
research in the history and sociology of science that focuses on how
sciences are shaped by and within particular cultural contexts. For
example, Golan shows how the questions early microscopists asked
were significantly framed by forensic needs—the desire for
legal evidence that could distinguish human from animal blood
colored both the technical dimensions of microscopy's research
program and the microscopic community's sense of its function and purpose.
But this argument about the intermingling dimensions of scientific
and legal knowledge-production is largely left implicit; Golan does
not overtly situate his book within any of the larger theoretical
debates among scholars studying the history and sociology of
science. Although more reflection on how the book contributes to
these broader debates would have been helpful, there are some
advantages to Golan's decision: It increases the book's readability,
and it shows off his fine narrative skills.
The opening chapter, one of the most successful, traces the actual
history behind an iconic 18th-century case, Folkes v.
Chadd, concerning whether a man-made embankment was the cause
of the decay of Wells Harbor in Norfolk, England. This case has gone
down in evidence treatises as an origin story of sorts for the
received history of the partisan expert witness, and is often cited
as the first case in which parties were allowed to call their own
experts and the first in which experts were allowed to testify not
only to facts but to opinions. Golan effectively debunks both of
these myths, showing first that party-controlled expert evidence was
already accepted, and further, that the witnesses in Folkes v.
Chadd did not merely provide their conclusory opinions but had
spent much time writing detailed reports based on firsthand
investigation and observation. Golan's historical skills are at
their best here, as he weaves together both the scientific and legal
dimensions of previously untold elements of the history of the case.
He shows, for example, how epistemological debates within emerging
scientific communities played out as the parties' experts were
pitted against each other—natural philosophy on one side and a
more practically oriented empiricism on the other.
Golan trained as a historian of science, and it shows to good effect
both in this and later chapters. When he details the history of
forensic microscopy, he describes the technical debates clearly and
succinctly, showing, for example, how the fledgling professional
community responded to concerns about the standardization of
instruments and measurement problems. Golan generally takes
seriously both the legal and scientific dimensions of his topic, but
occasionally he privileges the scientific over the legal, taking us
further inside the scientists' debates than those of the lawyers,
judges and legal commentators.
In the microscopy chapter, for example, we learn that the scientific
establishment largely rejected the idea that human blood corpuscles
could be sufficiently distinguished from those of other mammals to
allow for definitive testimony about whether a bloodstain (found,
say, on the clothing of a suspect) was of human origin. But some
experts nonetheless regularly testified about this issue in court.
Golan effectively describes the ongoing controversies among the
leading microscopists. They struggled over issues of standardizing
microscopes, worried about interspecies and intraspecies
variation in the size of blood corpuscles, and wrestled with
philosophical concerns about how confident they ought to be before
ethics permitted allowing an opinion in the court of law. But the
legal details are largely missing. We do not learn, for example,
what those experts who did testify actually said. Did they claim
certainty, or merely articulate the possibility that the bloodstain
was human? Were they ever cross-examined effectively, and if so,
how? Did leading experts testify for the defense in response,
arguing that definitive identification of human blood was not
scientifically plausible? Similarly, Golan reports that in England,
by 1875 courts were permitted to hear civil cases without a jury
when complex technical evidence was at issue, but we are not told
anything about how this institutional change took place, the extent
to which judges exercised this power or what consequences resulted.
Although Golan frequently references the legal system's anxiety over
expert charlatans and opportunists whose testimony was unduly
colored by partisan allegiances, this leitmotif remains somewhat
underdeveloped in his actual case studies. In his generally
sympathetic account of the struggles among emerging scientific
professionals, such as microscopists, radiologists and chemists, we
are not provided with concrete examples of experts whose testimony
so far exceeded the bounds of reputable scientific knowledge as to
justify the frequent harsh critiques put forth by
lawyers—fears of "liars, damned liars, and experts."
Was, then, this intense anxiety justified? Were there in fact many
charlatans who would say anything for the right price? Or did the
legal vitriol stem more from legal misunderstandings about the
nature of science than from the prevalence of unethical experts?
Golan's book illustrates but does not fully explain an intriguing
rhetorical mismatch between the enormous skepticism expressed by
legal commentators and the internal debates of the expert communities.
Throughout the 19th century, judges saw their screening role for
scientific expertise as extremely limited. Generally they evaluated
only the credentials of the expert, not the substance of the
testimony. This changed, in Golan's account, with the advent of the
polygraph, which was seen to threaten legal fact-finding processes
and even legal autonomy, because it suggested substituting the
judgment of an expert, or still worse, a machine, for the judgment
of a jury. According to Golan, the famous 1923 Frye test became the
wedge through which scientific evidence began to get more
substantive scrutiny, a trend that has continued and accelerated up
to the present. Indeed, in his final chapter and his epilogue, Golan
suggests that the story of the reception of expert evidence is a
tale of an increasingly "exclusionary spirit," a growing
distrust that has led to the increased scrutiny and control of
scientific information by the judiciary.
Golan is surely right as far as he goes, but his conclusion misses
out on certain ironies. Although judicial gatekeeping over expert
evidence has indeed increased since the early 19th century, the
justification for the increased scrutiny is precisely an increased
recognition of how critically important expert evidence is within
the legal sphere. The sometimes awkward efforts to evaluate and to
exclude invalid expert testimony, as required by the aforementioned
trilogy of recent Supreme Court rulings, is born precisely out of a
yearning to make the "laws of men" more consistent with
the "laws of science." Whether the yearning is admirable
or misplaced, feasible or unrealistic, remains an open question. But
the impulse behind the increased scrutiny of expert evidence is
assuredly faith in science, not its opposite.
These criticisms should not detract from Golan's accomplishment: He
has written the first book-length history of expert evidence in
common-law courts, and it is an impressive achievement. Golan shows
remarkable comfort with both legal and scientific discourse—an
ability that rather dramatically distinguishes him from the subjects
about whom he writes: lawyers and scientists who consistently reveal
grave discomfort, miscomprehension and even downright hostility when
confronted with each other. Both lawyers and scientists alike would
be well served by reading this account of their shared past.