Politics, according to famed political scientist David Easton, is about “the authoritative allocation of social values.” Values refer to desired outcomes which include both the substance of policy and the procedures used to achieve outcomes. For instance, good health is an example of valued substantive outcome. Public participation in the making of policy is and example of a valued procedural outcome. Politics is necessary because people, as individuals and collections of individuals, have different conceptions about what substantive and procedural outcomes, or what rankings of outcomes, are desirable in society.

From this perspective consider this view of the relationship of science and values, written last week by Alan Leshner, CEO of AAAS, in The Chronicle of Higher Education:

Credible scientists never contradict or go beyond the available data. We should never insert our personal values into discussions with the public about scientific issues. On the other hand, it is important to recognize that the rest of society is not constrained in that way and can mix facts and values at will.

That is another principle scientists find hard to accept, as they often have strong moral values. When a scientist brings personal views on, say, the beginning of life into a supposedly scientific discussion on the use of embryonic stem cells in research, his or her credibility as a source of neutral facts is automatically diminished. No matter what a scientist believes about moral issues, if an opponent in a debate introduces values or beliefs, the scientist should disclaim any ability to comment on those issues as outside the scientific realm.

Leshner’s perspective has been called the “fact-value distinction,” which holds that facts and values can be cleanly separated. Scientists, the argument goes, focus only on facts, and not values. There are of course some situations in which it makes good sense for scientists to focus on narrow technical questions, like “Where is the tornado heading?” But scholars who have studied the roles of science in society have come to a robust consensus that the situations in which policy making is best served by the scientific arbitration of facts are limited to some very unique circumstances.

From the perspective of theory, scholars of science in policy and politics have for many years understood that the fact-value distinction doesn’t hold up. As an example of this research, consider the following excerpts from Shelia Jasanoff’s excellent book, “The Fifth Branch: Science Advisors as Policymakers” (1990), (at pp. 230-31). Jasanoff, a leading voice in the discipline of science, technology, and society, focuses on science advisory bodies and organizations that bring science to decision makers and the public,:

Although pleas for maintaining a strict separation between science and politics continue to run like a leitmotif through the policy literature, the artificiality of this position can no longer be doubted. Studies of scientific advising leave in tatters the notion that it is possible, in practice, to restrict the advisory practice to technical issues or that the subjective values of scientists are irrelevant to decision making.

She also writes (at p. 249),

The notion that scientific advisors can or do limit themselves to addressing purely scientific issues, in particular, seems fundamentally misconceived … the advisory process seems increasingly important as a locus for negotiating scientific differences that have political weight.

In practice, scientists are always introducing their values into public debate. In fact, any effort at public communication is necessarily an expression of a scientist’s values – the procedural value that the public would be better off with whatever information that the scientist is sharing. And in many cases scientists go well beyond procedural values and make public statements to advocate for specific political outcomes. For example, Leshner (along with AAAS president John Holdren) recently wrote (in PDF):

There is a clear message in the growing torrent of studies revealing that impacts of global climate change are already occurring: It is time to muster the political will for serious evasive action. . . The United States — the largest emitter of carbon dioxide on the planet — needs to become a leader instead of a laggard in developing and deploying serious solutions.

Leshner may believe that the substantive (action on energy policy) and procedural (U.S. leadership) values that he is expressing are not just his own personal values, but also in support of common interests, but they are an expression of values nonetheless. If Leshner stuck to his own advice about not expressing values “beyond the scientific realm” he would have refrained from calling for certain types of policy action. In fact, if scientists generally followed Leshner’s advice there would be essentially no public views expressed by scientists. This of course is neither realistic nor desirable. Effective policy making requires the integration of science and values, not their separation.

Leshner’s views on facts and values is contradicted by the AAAS, ironically enough in a story on its home page right next to Leshner’s Chronicle piece, containing calls for more scientists to play a role in overt political advocacy.

The important distinction to be made is not whether or not scientists should express values in their public statements. It is how they express those values. They can chose to serve as political advocates by seeking to reduce the scope of choice to some preferred outcomes, or they can seek to expand or clarify choice. In all but the most simple of decision contexts there is simply no option to “disclaim any ability to comment on those issues as outside the scientific realm.” Those who give scientists such advice far out of step with robust knowledge of the roles of science in society only contribute to the pathological politicization of science.