Reprinted from Environmental Science and Policy, Vol.3(1), 2000, 19-20.
Copyright 2000, with permission from Elsevier Science.


"Most institutions demand unqualified faith;
but the institution of science makes skepticism a virtue."
(Merton, 1962)

Most scientists acknowledge the importance of making science relevant and useful in policy making, while recognizing that policy is not, and should not be, based on science alone.

In recent decades, investigations of major environmental issues such as climate change, acid rain, smog, and hypoxia have resulted in the conduct of complex integrated assessments. Such assessments organize information for the purpose of improving the effectiveness of policy making.

In policy making, especially in a political arena, consensus building is a key ingredient. In attempts to make science relevant and useful, the politics of democracy tend to promote, even in some cases demand "scientific consensus." However, as a "community of belief" develops, skepticism is no longer regarded as a virtue. In a civilization that is founded on science, this is an unfortunate state of affairs and detrimental to our future.

In order to appreciate this concern, it is necessary to revisit the central role of skepticism in science. Let us start with a dictionary definition of skepticism. Webster's Dictionary defines skepticism as: "A critical attitude towards any theory, statement, experiment, or phenomenon, doubting the certainty of all things until adequate proof has been produced; the scientific spirit." The Greek root of skepticism is identified as "skepticos", which means "thoughtful, inquiring."

For centuries, science has been founded on well-established methods of scientific investigation, which include recognition that "A scientific theory must be tentative and always subject to revision or abandonment in light of facts that are inconsistent with, or falsify, the theory. A theory that is by its own terms dogmatic, absolutist and never subject to revision is not a scientific theory" (Judge William R. Overton, in Science, 1982). Thus, a basic tenet of science is for scientists to posit and test hypotheses and theories. Scientific progress is made by accepting or rejecting hypotheses at specified levels of confidence, thus embodying skepticism in the heart of scientific methodology.

There are two dominant and somewhat opposing philosophies on testing hypothesis and theories. One philosophy is that the purpose of hypothesis testing is to validate - to support or corroborate - a hypothesis. The other philosophy is that the purpose of hypothesis testing is to attempt to invalidate a hypothesis. And the same applies to model testing; there are scientists who attempt only to validate models, and others who state that the true application of the scientific method includes attempts to invalidate models and to show the limits of applicability of models. In science, attempts to invalidate hypotheses and models - hard-core skepticism, by any definition - should be viewed as a necessary positive step in the pursuit of truth. Rigorous hypotheses and models will emerge as triumphant - at least for the time being. In a problem-solving and policy-development mode, healthy skepticism is needed to ensure the rigor and effectiveness of proposed solutions. Another way of expressing the difference between these two philosophies is to state that "Blind commitment to a theory is not an intellectual virtue; it is an intellectual crime" (Lakatos, 1978).

This is why I regard consensus science and the demise of scientific skepticism as an unhealthy combination. Without the boldness and perseverance of earlier skeptics, who risked ridicule and being branded as heretics, we would still believe Earth to be the center of the Universe and continents to be motionless.

Taking the issue of climate change as an example, there are healthy signs of increasing recognition of the importance of dealing with important methodological uncertainties. Petersen (1999), in an inspiring article entitled "Philosophy of Climate Science", states that, "Climate science has to deal with important methodological problems concerning climate simulation. Among these are methodological problems related to climate model hierarchy and complexity, tuning and falsifiability, and uncertainty. All these subjects have only recently become topics of discussion within the climate science community." He finds that uncertainties are currently not thoroughly and methodologically assessed for the purposes of policy usefulness of climate science. Barnett et al. (1999), in a scholarly article summarizing the status of detection and attribution of an anthropogenic climate signal, also find that "Only recently has detection work paid serious attention to the variety of uncertainties that attend the observations and model projections of an anthropogenic signal."

We must find improved ways of preserving and strengthening the time-honored method of scientific investigation, which includes promoting skepticism in the search for truth. We must do this at the same time that we find improved ways of making science more useful in policy making. A stronger culture of critical debate and organized skepticism needs to be fostered.

One way of achieving these goals is for those who organize and conduct integrated assessment, and those who will use their results, to ensure that the assessments rigorously test multiple working hypotheses, identify clearly what we know and do not know, include minority (or seemingly external) views, and express confidence levels on the findings. In a political system that is based on checks and balances, substantial constituency input to and strong external oversight of the assessment process are needed to ensure the integrity of science. An Office of Science and Technology in Congress could provide the needed oversight.

The crux of the problem is how science is taught and practiced. To protect science in the long term, "a healthy dose of skepticism" should be introduced into every young scientist's education, and more training should be provided for studying and expressing uncertainty at all levels of professional development. The scientific community should raise the standards of peer review and the demands of "adequate proof."

If science is not to be subsumed by policy, and scientists are not to be turned into politicians, then, as Jacob Bronowski recognized, science ".... must protect independence. The safeguards which it must offer are patent: free enquiry, free thought, free speech, tolerance" (Bronowski, 1958). While Bronowski went too far when he called for the "disestablishment of science" - the separation, as complete as possible, between science and government - science today needs increased safeguards.


Barnett, T.P., et al. 1999. Detection and attribution of recent climate change: a status report. Bull.Am.Met.Soc. 80(12), 2631-2659.

Bronowski, Jacob. 1958. Science and human values. Penguin Books Ltd., p.68.

Lakatos, Imre. 1978. Philosophical Papers 1, Cambridge U. Press, p.1

Merton, Robert K. 1962. Social theory and social structures. Free Press, NY., p.547.

Petersen Arthur C. 1999. Philosophy of climate science. Bull.Am.Met.Soc. 81(2), 265-271.

Science, 1982. Creationism in schools: the decision in McLean versus the Arkansas Board of Education. Science (215), 934-943.


The views expressed in this editorial are those of the author and do not necessarily reflect the views of the Illinois Department of Natural Resources.

Derek Winstanley
Chief, Illinois State Water Survey
Illinois Department of Natural Resources

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