Scientific Uncertainty and Public Debate over Science

Russell Blackford

Since the rise of a recognizably modern form of science early in the seventeenth century—associated above all with Galileo—science has emerged as “our most authoritative source of knowledge about the natural world” (Heather E. Douglas, whose work partly inspired this column) within which I include knowledge of a general kind about ourselves. Almost everyone agrees at an abstract level that science is authoritative and that it eventually produces reliable findings. Though we sometimes see challenges to science’s overall authority, these have little appeal to policymakers or everyday people; they are mostly a luxury enjoyed by certain tribes of academics with commitments to the religious Right or the cultural-relativist Left.

The situation is, however, different when attention turns from the overall authority of science to the reliability of any particular set of scientific claims, especially if it appears to have implications for public policy. Nor is it always unreasonable to scrutinize and perhaps resist particular scientific claims. On the contrary, scrutiny and resistance have their place in science’s advance. Life would be tidier, and simpler in its challenges, if we could brand all resistance as science denial and dismiss it out of hand. Alas, life is not tidy.

Scientific claims are sometimes little more than reports of observations using sophisticated and systematic methods. But very often, and perhaps almost always in controversial cases, scientific claims depend on arguments that connect the observational data to conclusions. The result is never 100 percent guaranteed, and what seems a correct inference today might be discarded tomorrow if disconfirming evidence turns up. Furthermore, in many cases, especially when highly intricate systems are the subject of study, no flawless methodology is available. That is, there is no practical way to eliminate all possible confounding factors, dubious background assumptions, and the like. Even if the methodology is very impressive when judged against these problems, it might produce conclusions with a margin—perhaps a large margin—of uncertainty. In all such cases, there can be legitimate questions as to how far policymakers and everyday people should rely on particular scientific claims.

Fortunately, some scientific claims are so well-evidenced, from so many independent directions of inquiry, that there is no real room for doubt. There’s no serious prospect that these claims will be overturned at some point in the future. This applies, for example, to heliocentrism (we can be absolutely confident that our planet rotates on its axis while revolving around the sun), the fundamentals of biological evolution, and, in a general way, the findings from biomedical science about the great dangers of smoking tobacco.

By now, we’ve also reached or passed this point with the basics of anthropogenic global warming. While there is room for argument about the details and about exactly what should be done in response, we can be confident that the phenomenon is both real and dangerous. The denial of anthropogenic global warming is also likely, on any particular occasion, to be ill-informed, expressed in bad faith, or sustained by cognitive biases. For policymakers—and for everyday people deciding how to vote—this science can be taken as settled, and it’s well past time to focus on what constitutes a rational and caring response.

It doesn’t follow that all scientific findings should be accepted uncritically, either by policymakers trying to promote collective welfare or by the rest of us in our everyday lives trying to understand the world and act for the best. Some areas of science are constantly shifting, many findings involve uncertainties that the scientists concerned are well aware of, and many fields and subfields contain much internal debate and controversy. When it comes to issues such as recommendations for a healthy diet, about the best we can usually do is follow whatever is closest to current scientific consensus, as conveyed by our own physicians. But we should also be aware that research in this area is fraught with difficulties, and we should not be too surprised when findings change over time or if certain political and moralistic biases creep into advice given to the public.

Even more troubling, the behavioral sciences are notably volatile, uncertain, in many cases fraught with difficulties that preclude truly decisive experiments, and often dependent on underlying assumptions and intuitions that are themselves doubtful. It shouldn’t be too surprising that these fields are wracked by internal controversy or that in many cases are open to external criticism on methodological and other grounds. All this should be seen not so much as a state of crisis in fields such as social psychology but as the inevitable nature of these fields at this stage of their development and with their inherent difficulties.

Again, it would be nice if scientists across the board from psychology to physics delivered findings that were clear, certain, and permanent. But that’s not how science works. The overall authority of the scientific enterprise depends, in part, on a crucible of scrutiny in which genuinely reliable scientific claims are forged. Unfortunately, it requires significant knowledge and judgment to distinguish between (on one hand) legitimate scrutiny of uncertain and consequential scientific claims and (on the other hand) outright science denial—and this, in turn, implies that accusations of science denial should be made with care. Sometimes they are justified, as readers of Free Inquiry well know, but they should be supported by good information and well-trained discernment.

How, though, do we impart that kind of discernment? Educating policymakers, public controversialists, and ordinary voters in this complex area will be a twenty-first-century challenge. We need far more sophisticated and well-informed public debate over scientific claims and their implications, and we need much more attention from our schools and universities to the history, nature, methods, and trajectory of science.

Russell Blackford

Russell Blackford is a conjoint senior lecturer in philosophy at the University of Newcastle (Australia) and a regular columnist for Free Inquiry. His latest book, The Tyranny of Opinion: Conformity and the Future of Liberalism (2019), is published by Bloomsbury Academic.


Since the rise of a recognizably modern form of science early in the seventeenth century—associated above all with Galileo—science has emerged as “our most authoritative source of knowledge about the natural world” (Heather E. Douglas, whose work partly inspired this column) within which I include knowledge of a general kind about ourselves. Almost everyone agrees …

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