Why Trust Science?

by Naomi Oreskes

  Getting Unstuck: Social Epistemology

  Despite the challenges of science studies, there have still been many attempts to salvage scientific rationality. In my view, the most successful of these have come from a direction that most scientists would have least suspected: feminism.

  Since the 1960s, feminists have asked: How could science claim to be objective when it largely excluded half the population from the ranks of its practitioners? How could science claim to be producing disinterested knowledge when so many of its theories embedded obvious social prejudices, not just about gender but also about race, class, and ethnicity? These questions were not necessarily hostile. Many of them were raised by female scientists who were interested in the natural or social world and believed in the power and value of scientific inquiry to explain it.

  Sociologists of scientific knowledge stressed that science is a social activity, and this has been taken by many (for both better and worse) as undermining its claims to objectivity. The “social,” particularly to many scientists but also many philosophers, was synonymous with the personal, the subjective, the irrational, the arbitrary, and even the coerced. If the conclusions of scientists—who for the most part were European or North American men—were social constructions, then they had no more or less purchase on truth that the conclusions of other social groups. At least, a good deal of work in science studies seemed to imply that.

  But feminist philosophers of science, most notably Sandra Harding and Helen Longino, turned that argument on its head, suggesting that objectivity could be reenvisaged as a social accomplishment, something that is collectively achieved.89 Harding mobilized the concept of standpoint epistemology—the idea that how we view matters depends to a great extent on our social position (or, colloquially, that where we stand depends on where we sit)—to argue that greater diversity could make science stronger. Our personal experiences—of wealth or poverty, privilege or disadvantage, maleness or femaleness, heteronormativity or queerness, disability or able-bodiedness—cannot but influence our perspectives on and interpretations of the world. Therefore, ceteris paribus, a more diverse group will bring to bear more perspectives on an issue than a less diverse one.90

  In her groundbreaking 1986 book, The Science Question in Feminism, Harding argued that the objectivity practiced by most scientific communities was weak, because of the characteristic homogeneity of those communities. The perspectives of women, people of color, the working classes, and many others were lacking, and the consequences were plain to see when one considered the obvious sexism, racism, and class bias of many past scientific theories. But there could be less obvious forms of bias at work as well. She argued for what she labeled strong objectivity: an approach that acknowledged that an individual’s beliefs, values, and life experiences necessarily affect their work—scientific or otherwise—so the best way to develop objective knowledge is to increase the diversity of knowledge-seeking communities. Objectivity was not a 0/1 proposition: communities could be more or less objective and greater objectivity in scientific research achieved—or at least made more likely—by greater heterogeneity in the scientific community.91

  Like Feyerabend, Harding tended toward the deliberately provocative—as when she compared Newton’s Principia Mathematica to a rape manual—and this made her an easy target of right-wing critics.92 It also made her the target of scientific critics, such as Paul Gross and Norman Levitt, who failed to understand that the central point of her critique was that science could be made stronger through inclusion. This point was made a bit more diplomatically—albeit equally forcefully from an intellectual standpoint—by the feminist philosopher Helen Longino.

  Longino transformed a common scientific assumption—that science is self-correcting—into a pressing intellectual question—How is it that science is self-correcting? After all, the claim that science corrects itself might be viewed as highly implausible—a sort of epistemic magic trick. Longino’s suggested that it is not so much that science corrects itself, but that scientists correct each other through the social processes that constitute “transformative interrogation.” It is through the give and take of ideas—the challenging, the questioning, the adjusting and amending—that scientists integrate their colleagues’ work, offer up criticisms, and contribute to the growth of warranted knowledge. She wrote:

  The objectivity of individuals in this scheme consists in their participation in the collective give-and-take of critical discussion and not in some special relation (of detachment, hardheadedness) they may bear to their observations. Thus understood, objectivity is dependent upon the depth and scope of the transformative interrogation that occurs in any given scientific community.93

  Longino urged us to accept (rather than lament) the fact that individual scientists invariably bring biases, values, and background assumptions into their work. The scientist entering the laboratory cannot hang up her personal values, preferences, assumptions, and motivations like an overcoat, as Claude Bernard once supposed.94 What can happen, however, is that in a diverse community subjective elements can (and most likely will) be challenged by others, and to the extent that they may be inappropriately informing evidential reasoning and theory choice, that can be challenged, too.95

  Longino’s account of transformative interrogation solves the problem of how science, as a whole, can be objective even when individual scientists are not:

  If scientific inquiry is to provide knowledge, rather than a random collection of opinions, there must be some way of minimizing the influence of subjective preferences and controlling the role of background assumptions. The social account of objectivity solves this problem. The role of background assumptions in evidential reasoning is grounds for unbridled relativism only in the context of an individualistic concept of scientific method and scientific knowledge.… Values are not incompatible with objectivity, but objectivity [emerges] as a function of community practices rather than as an attitude of individual researchers.96

  This perspective reinforces Harding’s position that objectivity is not a matter of either/or, but of degree. The greater the diversity and openness of a community and the stronger its protocols for supporting free and open debate, the greater the degree of objectivity it may be able to achieve as individual biases and background assumptions are “outed,” as it were, by the community. Put another way: objectivity is likely to be maximized when there are recognized and robust avenues for criticism, such as peer review, when the community is open, non-defensive, and responsive to criticism, and when the community is sufficiently diverse that a broad range of views can be developed, heard, and appropriately considered. On this view, it is not surprising that when scientists were almost exclusively white men, they developed theories about women and African Americans that were at best incomplete and at times pernicious—theories that have now been rejected. Nor is it surprising that many of the logical and empirical flaws of these earlier theories were pointed out by women and people of color.97 (This point is addressed further in chapter 2.)

  The key point here is that often “assumptions are not perceived as such.”98 They are so embedded as to go unrecognized as assumptions, and this is most likely to occur in homogeneous communities. Longino continues:

  When, for instance, background assumptions are shared by all members of a community, they acquire an invisibility that renders them unavailable for criticism. They do not become visible until individuals who do not share the community’s assumptions can provide alternative explanations of the phenomena without those assumptions, as, for example, Einstein could provide an alternative explanation of the Michelson-Morley interferometer experiment [because he did not share the assumption of the variable speed of light].… From all this it follows again that the greater the number of different points of view included in a given community, the more likely it is that its scientific practice will be objective … [and] it will result in descriptions and explanations of natural processes that are more reliable … than would otherwise be the
case.99

  Transformative interrogation can empower us to decide whether those background assumptions are, in a given context, appropriate and helpful or inappropriate and unhelpful. This is most likely to occur in a diverse community for the simple reason that diverse communities will have diverse background assumptions. Diversity does not heal all epistemic ills, but ceteris paribus a diverse community that embraces criticism is more likely to detect and correct error than a homogeneous and self-satisfied one.100

  Feminist epistemology soundly refutes the claim that the social character of science makes it subjective. On the contrary, we can now see that scientists who were offended by the social turn in science studies—as well as science studies scholars who thought they could debunk science by exposing its social character—got it wrong. The feminist account of the social character of science can make a stronger case for the objectivity of scientific knowledge than previous accounts by identifying both sources of bias and remedies to it. And consider this: in their dyspeptic polemic of the 1990s, Higher Superstitions: The Academic Left and Its Quarrels with Science, scientists Paul Gross and Norman Levitt accused feminists of being anti-science. But neither Harding nor Longino were anti-science.101 Both were discussing ways to strengthen and improve it. Gross and Levitt could have used feminist philosophy of science in their defense of science had they not been so busy taking offense.

  In Diversity There Is Epistemic Strength

  Feminist philosophy of science salvages science from the claim that its social character makes it subjective, but it does leave us with a view of science that makes some people uncomfortable: that science is fundamentally consensual. Longino summarizes: “To say that a theory or hypothesis was accepted on the basis of objective methods does not entitle us to say it is true but rather that it reflects the critically achieved consensus of the scientific community. [And] it’s not clear we should hope for anything better.”102 I agree. But where does that leave us?

  To recapitulate: There is now broad agreement among historians, philosophers, sociologists, and anthropologists of science that there is no (singular) scientific method, and that scientific practice consists of communities of people, making decisions for reasons that are both empirical and social, using diverse methods. But this leaves us with the question: If scientists are just people doing work, like plumbers or nurses or electricians, and if our scientific theories are fallible and subject to change, then what is the basis for trust in science?

  I suggest that our answer should be two-fold: 1) its sustained engagement with the world and 2) its social character.

  The first point is crucial but easily overlooked: Natural scientists study the natural world. Social scientists study the social world. That is what they do. Consider a related question: Why trust a plumber? Or an electrician? Or a dentist or a nurse? One answer is that we trust a plumber to do our plumbing because she is trained and licensed to do plumbing. We would not trust a plumber to do our nursing, nor a nurse to do our plumbing. Of course, plumbers can make mistakes, and so we get recommendations from friends to ensure that any particular plumber has a good track record. A plumber with a bad track record may find herself out of business. But it is in the nature of expertise that we trust experts to do jobs for which they are trained and we are not. Without this trust in experts, society would come to a standstill. Scientists are our designated experts for studying the world.103 Therefore, to the extent that we should trust anyone to tell us about the world, we should trust scientists.

  This is not the same as faith: We do (or should) check the references of our plumbers and we should do the same for our scientists. If a scientist has a track record of error, underestimation, or exaggeration, this might be grounds for viewing his or her claims skeptically (or at least judging their results with this information in mind.) If a scientist is receiving financial support—directly or indirectly—from an interested party, this may be grounds for applying a higher level of scrutiny than we might otherwise demand. (For example, an editor might send the paper for additional review, or a reviewer might pay extra attention to study design, where subconscious bias may slip in.)104

  No doubt individual scientists, like individual plumbers, may be stupid, venal, corrupt, or incompetent. But consider this: the profession of plumbing exists because in general plumbers do a job we need them to do, and in general they do it successfully. When we evaluate the track record of science, we find a substantial record of success—in explanation, in prediction, in providing the basis for successful action and innovation. We have a world of medicines, technologies, and conceptual understandings derived from science that have enabled people to do things they have wanted to do. (As already noted, that success does not prove that the theories involved are necessarily true, but it does suggest that scientists are doing something right.) This might be the one point on which the diverse scholars I have discussed agree: philosophers, historians, sociologists, and anthropologists have all been interested in science because of its success—both culturally and epistemologically. The question of this lecture is of interest at least in part because the success of science as a source of stable epistemic authority has been called into question, and its future success as a cultural enterprise appears to be at least somewhat in doubt.

  This consideration—that scientists are in our society the experts who study the world—is a reminder to scientists of the importance of foregrounding the empirical character of their work—their engagement with nature and society and the empirical basis it provides for their conclusions. As I have stressed elsewhere, scientists need to explain not just what they know, but how they know it.105 Expertise as a concept also carries with it the embedded idea of specialization, and therefore the limits to expertise, reminding us why it is important for scientists to exercise restraint with respect to subjects on which they lack expertise.

  However, reliance on empirical evidence alone is insufficient for understanding the basis of scientific conclusions and therefore insufficient for establishing trust in science. We must also take to heart—and explain—the social character of science and the role it plays in vetting claims. Here it is worth reiterating my point that scientists who were offended by the “social” turn in science studies got it wrong: much of what we identify as “science” are social practices and procedures of adjudication designed to ensure—or at least to attempt to increase the odds—that the process of review and correction are sufficiently robust as to lead to empirically reliable results.106 Again, Longino: “Socializing cognition is not a corruption or displacement of the rational but a vehicle of its performance.”107

  Peer review is one example of such a practice: it is through peer review that scientific claims are subjected to critical interrogation. (This is why, in my own work, I have stressed the importance of evaluating scientific consensus through analysis of the peer-reviewed literature and not the popular press or social media, and why these chapters were subject to peer review.) This includes not only the formal review that papers go through when submitted to academic journals, but also the informal processes of judgment and evaluation that research findings undergo when scientists discuss their preliminary results in conferences and workshop and solicit comments from colleagues prior to submitting them for publication, as well as the continued process of evaluation that published claims endure as fellow scientists attempt to use and build on those claims.108

  Tenure is another example: we evaluate scholars’ work in order to judge whether they are worthy of joining the community of scholars in their fields, in effect to be certified as experts. Tenure is effectively the academic version of licensing. The crucial element of these practices is their social and institutional character, which work to ensure that the judgments and opinions of no one person dominate and therefore that the value preferences and biases of no one person are controlling. Of course, within any community there will be dominant groups and individuals, but the social processes of collective interrogation offer a means for the less
dominant to be heard so that, to the maximum degree possible, the conclusions arrived at are non-partisan and non-idiosyncratic.109 The social character of science forms the basis of its approach to objectivity and therefore the grounds on which we may trust it.

  In recent years, this insight has been implicitly incorporated into scientific practices, particularly in just those domains where scientific claims are likely to be viewed as controversial. The US National Academy of Sciences works to ensure that the panelists who perform its reviews are diverse and represent a range of viewpoints. Scholars have called this approach the “balancing of bias.”110 The Intergovernmental Panel on Climate Change—now one of the world’s largest aggregations of scientists—makes a particular point of seeking geographical, national, racial, and gender diversity in its chapter-writing teams. While the motivations for inclusivity may be in part political, the widespread character of practices of inclusion suggest that many scientific communities now recognize that diversity serves epistemic goals.

  Caveats

  My arguments require a few caveats. Most important is that there is no guarantee that the ideal of objectivity through diversity and critical interrogation will always be achieved, and therefore no guarantee that scientists are correct in any given case. The argument is rather that, given the existence of these procedures and assuming they are followed, there is a mechanism by which errors, biases, and incompleteness can be identified and corrected. In a sense, the argument is probabilistic: that if scientists follow these practices and procedures, they increase the odds that their science does not go awry. Moreover, outsiders may judge scientific claims in part by considering how diverse and open to critique the community involved is. If there is evidence that a community is not open, or is dominated by a small clique or even a few aggressive individuals—or if we have evidence (and not just allegations) that some voices are being suppressed—this may be grounds for warranted skepticism. In this respect, each case must be evaluated on its own merits.