How the Law and the Sciences Think About Knowledge

In my posts this month, I have looked at how to improve the way social scientists and empirical legal scholars produce empirical knowledge. I want to focus this week on the legal side of this issue. Those who buy the arguments I have made so far should agree that evidence based systematic reviews are a superior way for academics and policy makers to assess what is known about a particular problem. But can we use these reviews in litigation setting?

Empirical evidence has long posed a problem to the adversarial, common law system. As Tal Golan points out in Laws of Men and Laws of Nature, courts have struggled for at least three centuries with how to use complex scientific evidence in the courtroom, and the problem is only going to get worse in the years to come. Lay judges and lay jurors have never had the epistemic competence to understand technical scientific and empirical evidence, and thanks to the technological revolution of the past three decades the volume and sophistication of such evidence is only going to grow. Some sort of reform is inevitable, and I think a shift towards courtroom-EBP is the way to go.

Yet the history of the law's use of science is little more than a history of failed reforms. Why should we expect a different outcome this time? After all, we're all familiar with Einstein's famous quote about Quixotic endeavors. I am actually optimistic, but I am still fleshing out fully the reason for my optimism. So I want to present it here as a tentative claim, and I look forward to seeing what people have to say about it in the comments.

My basic claim is this: The rise of EBP reflects a change in scientific epistemology. In particular, it reflects a move away from what was effectively an adversarial model towards a more collaborative approach. In other words, earlier efforts at reform failed in no small part because of the strong similarities between legal and scientific epistemologies. Both relied on adversarial approaches, so when reformers called on the law to adopt non-adversarial approaches, they were calling on adversarial legal actors to behave less adversarially than the scientists. That lawyers and judges resisted should come as no surprise. But EBP reflects a fundamental epistemological shift, and as a result it provides a real opportunity for reform.

That is my claim, and I'll defend it briefly here. But it is a working hypothesis, and I am eager to get people's thoughts about it.

That law's epistemology is adversarial does not require any explanation on this blog. Each party is called on to find its own experts and its own evidence. Each party presents its case, and the other side tries to punch holes in it during cross. We have introduced some "inquisitorial" practices--screening under Daubert, special masters, Rule 706 experts--but our approach remains predominantly adversarial. Even the order of evidence reflects the adversarial mindset: the two sides of the scientific story are not presented at the same time but during each party's presentation of all its evidence. (Although this might be changing a bit with the development of hot-tubbing.) The system relies, perhaps implicitly, on the "marketplace of ideas" metaphor. Let the two sides duke it out, and at least more often than not the right answer will prevail. 

That the sciences have been essentially adversarial is perhaps less clear. There have always been famous rivalries, such as that between Newton and Leibnitz, and scientists are professional skeptics, trained to constantly push, prod, and poke holes in the works of others to see what survives. But there is still a common belief that scientists, unlike partisan experts, share a common goal: discovering the truth, not proving (or "proving") a pre-determined outcome.

And at some level, this is surely true. But the day-to-day practice looks much more like something adversarial. Experts often become wedded to a particular perspective for both sincere and cynical reasons (the effect of corporate sponsorship on research, particularly on medical and pharmaceutical research, is becoming an important issue). And as a result, debates in the empirical literature can take on a partisan feel similar to that in the courtroom. The analogy is far from perfect--academic scientists are surely in general less outcome-oriented than courtroom experts, and the "jury of their peers" is far more epistemically competent--but I think it captures the basic feel of academic debates.

As a result, it is not surprising that the law resisted efforts to introduce the "independent expert" into the courtroom. Scientists do not resolve empirical questions by looking to one expert to synthesize the literature but by debating constantly among themselves. How could they ask lawyers and judges to act in a more centralized and collaborative manner than they themselves do?

But evidence based policy is a powerful move away from such an adversarial approach. By bringing together an entire literature, and by developing rigorous and objective ex ante standards, EBP reflects a substantially less adversarial and more collaborative epistemology. And thus for the first time it offers up a qualitatively different way of assessing what we do and do not know. For the first time, empirical disciplines can look at the law's dueling experts and say: "No, we really do produce knowledge in a fundamentally different way."

In my next post, I will look at how to reconcile the EBP's non-adversarial bent with the norms that our adversarial procedures seek to protect.