From Post-Normal Science to Post-Normal Law?
Carl Cranor certainly understands the impact of Milward v. Acuity as you can see from his recent blog post at the Center for Progressive Reform. Over the coming days we'll examine several of Cranor's points but for today let's start with his enthusiastic approval of the appellate court's rejection of "an 'atomistic' study-by-study assessment of the scientific basis of expert testimony."
In the sort of scientific induction that is the basis for most expert opinion in toxic tort cases, broad conclusions are drawn from specific data. Thus in Milward, plaintiff's expert extrapolated from four particular sets of data to his conclusion that benzene is generally capable of causing acute promyelocytic leukemia (APL) in humans. The trial court, however, reviewed each particular bit of data which supposedly supported the inference and found each to be wanting and so excluded the opinion. But the US Court of Appeals for the First Circuit held that "[t]he district court erred in reasoning that because no one line of evidence supported a reliable inference of causation, an inference of causation based on the totality of the evidence was unreliable." That court then went even further and adopted a view of how science is done that is advanced by just a small cadre of non-scientist academics. It approved Cranor's conception of scientific induction holding that "[t]he hallmark of the weight of the evidence approach is reasoning to the best explanation for all of the available evidence." The problem, for those of us stuck in The Enlightenment, is that an argument founded on false premises cannot, save by sheer accident, lead to the truth.
Let's say there are four studies recording the incidence of some disease in a work force and the dose, or exposure, to the chemical in question sustained by the workers being studied. The data, according to plaintiff's expert, looks like this:
From such data a scientist could reasonably infer that there is a relationship between dose and the incidence of disease and specifically that doubling the exposure doubles the risk of disease. Data like that is generally a powerful indicator of a true causal connection if subsequently confirmed by other studies. But let's say that we examine the four data points and find that the expert has either misreported or misinterpreted the data and that it really looks like this:
What the appellate court has said in Milward is that somehow, based solely on the subjective weight given each bit of data and his interpretation of "the totality" of the data, an expert is free to testify to a conclusion that not only is unsupported by, but is completely at odds with, the premises from which it was derived. What's going on here?
What's up is that the Court has bought into, whether it recognizes it or not, the concept of "post-normal science". It's an idea advanced by Jerome Ravitz and embraced by Carl Cranor and many in the movement that seeks to incorporate the precautionary principle into our laws. The idea is explicated most clearly in "Towards a Non-Violent Discourse in Science" in which Ravitz explains that the Enlightenment's view of science which has prevailed to this day - that "in the natural sciences, whose conclusions are true and necessary and have nothing to do with human will" ... we must "give up this idea and this hope of [ours] that there may be men so much more learned, erudite and well-read than the rest of us as to be able to make that which is false become true in defiance of nature" (Galileo Galilei) - is yielding to a new conception of science necessitated by our modern scary world. A world in which "facts are uncertain, values in dispute, stakes high and decisions urgent". A world in which Enlightenment-style science too often serves "the morally dubious worlds of profit, power and privilege".
Essentially the idea is that science has become "authoritarian". It imposes what it claims to be truth on people who have genuinely held beliefs that lead them to a very different conception of how the universe works. And when it comes to risk, it ignores social constructions of risk that lead people like Cranor to believe that, for example, autism is linked to pharmaceuticals, alcohol and living too close to a freeway. Consequently, "housewife epidemiology" and the fervently held beliefs of activists ought to be weighed in the scales of judgment alongside the data and the test results of such theories. (See "Legally Poisoned: How the Law Puts Us at Risk From Toxicants"). Most importantly it embraces the view that there are indeed people, experts, "so much more learned, erudite and well-read than the rest of us" as to hold a view of truth immune to, and indeed beyond the reach of, "normal science".
It's all, in our view, a dreadful misreading of Thomas Kuhn's "The Structure of Scientific Revolutions". It twists the conclusion that scientists are no happier to admit their errors than regular folks into a claim that all science is a sort of social construct - that there is no truth, and that what scientists really do is to weigh the facts they find relevant to a nicety in the scales of their subjective judgment. And by incorporating such a view into our law, originally, at least, derived from and founded upon the empiricism of the Enlightenment, we adopt a view in which the law exists not to guide our future actions as citizens but rather, typically ex post facto in the case of toxic torts, to support whatever fad or fear motivates us in the moment.
More in coming days.
