Wednesday, May 28, 2014

Scientism Reloaded

The "Reclaim Scientism" movement is gaining momentum. In his recent book "The Atheist's Guide to Reality: Enjoying Life without Illusions", the American philosopher Alexander Rosenberg suggests that instead of viewing the word "scientism" as an epithet, atheists should expropriate it and use it as a positive term which describes their worldview. Rosenberg also provides a descriptive explanation of how the term "scientism" is currently used:
Scientism — noun; scientistic — adjective.
Scientism has two related meanings, both of them pejorative. According to one of these meanings, scientism names the improper or mistaken application of scientific methods or findings outside their appropriate domain, especially to questions treated by the humanities. The second meaning is more common: Scientism is the exaggerated confidence in the methods of science as the most (or the only) reliable tools of inquiry, and an equally unfounded belief that at least the most well established of its findings are the only objective truths there are.
Rosenberg's explanation of "scientism" is helpful because it highlights the difference between science and scientism. Science refers to applying scientific methods as tools of inquiry to collect and interpret data, whereas "scientism" refers to cultural and ideological views promoting the primacy or superiority of scientific methods over all other tools of inquiry.  Some scientists embrace scientistic views, in part because scientism provides a much-needed counterbalance to aggressive anti-science attitudes that are prevalent on both ends of the political spectrum and among some religious institutions. However, other scientists are concerned about propping up scientism as a bulwark against ideological science-bashing because it smacks of throwing out the baby with the bathwater. Science is characterized by healthy skepticism, the dismantling of dogmatic views and a continuous process of introspection and self-criticism. Infusing science with ideological stances concerning the primacy of the scientific method could undermine the power of science which is rooted in its willingness to oppose ideological posturing.

As a scientist who investigates signaling mechanisms and the metabolic activity of stem cells, I am concerned about the rise of some movements that fall under the "scientism" umbrella, because they have the possibility to impede scientific discovery. Scientific progress relies on recognizing the limitations and flaws in existing scientific concepts and refuting scientific views that cannot be adequately explained by newer scientific observations. An exaggerated confidence in the validity of scientific findings could stifle such refutations. For example, some of the most widely cited scientific papers in the field of stem cell biology cannot be replicated, but they have had an enormous detrimental impact on the science and medicine, in part because of an exaggerated faith in the validity of some initial experiments.

I first began studying the use of stem and progenitor cells to enhance cardiovascular repair and regeneration over a decade ago. At that time, many of my colleagues and I were excited about a recent paper published by a group of scientists based at New York Medical College in the high-profile scientific journal Nature in 2001. The paper suggested that injected adult bone marrow stem cells could be successfully converted into functional heart cells and recover heart function after a heart attack by generating new heart tissue. The usage of adult regenerative cells was a very attractive option because it would allow patients to be treated with their own cells and could circumvent the ethical and political controversies associated with embryonic stem cells. This animal study gained even more traction when supportive experimental and human studies were published by other scientists. Then a German research group under the direction of the cardiologist Bodo Strauer published a paper in 2002 which showed that not only could adult human bone marrow cells be safely injected into heart attack patients but that these adult cells  even appeared to improve  heart function.

The stir caused by these discoveries was not just confined to scientists. The findings were widely reported in the media and I recall numerous discussions with physicians who claimed that cardiovascular disease would soon be a problem of the past, because patients would receive routine bone marrow injections after heart attacks. One colleague even advised me to reconsider my career choices since the usage of bone marrow cells could address most if not all issues in cardiovascular regeneration.

This excitement was somewhat dampened when a refutation of the 2001 Nature paper was published in 2004, also in the journal Nature. A collaborative effort of two US-based stem cell research groups was not able to replicate the findings of the 2001 paper. The scientists were unable to find any significant conversion of adult bone marrow cells into functional heart cells. However, many physicians, scientists and patients had already adopted an unshakable belief in the validity of the bone marrow cell treatments after heart attacks. Hundreds of heart attack patients were being enrolled in clinical trials involving the injection of bone marrow cells. Clinics in Thailand or Mexico began offering bone marrow injections to heart patients from all around the world– for a hefty price, both in terms of monetary payments and in terms of safety because they exposed patients to the risks of invasive injections of bone marrow cells into their hearts.

Despite the fact that the initial clinical studies with small numbers of enrolled patients had shown a beneficial effect of bone marrow cell injections, subsequent trials could not confirm these early successes. It became apparent that even if bone marrow cell injections did exert a therapeutic benefit in heart attack patients, these benefits were rather modest. Scientists increasingly realized that the observed benefits may have been causally unrelated to the small fraction of stem cells contained within the bone marrow. Instead of bone marrow stem cells becoming functional heart cells, some bone marrow cells may have merely released protective proteins which could explain the slight improvement in heart function, without necessarily generating new heart tissue. One of the largest bone marrow cell treatment trials for heart attack patients to date was just recently published in 2013 and showed no evidence of improved heart function following the cell injections.  

In hindsight, many of us have wondered why we were not more skeptical of the initial findings. When compared to embryonic stem cells, adult bone marrow stem cells have a very limited ability to differentiate into cell types other than those typically found in the bone marrow. Furthermore, the clinical studies which reported successful treatment of heart attack patients used unpurified bone marrow cells from the patients. The stem cell content of such unpurified preparations is roughly 1% or less, which means that 99% of the injected bone marrow cells were NOT stem cells. For the tiny fraction of bona fide stem cells in the bone marrow to convert into sufficient numbers of beating heart cells and even create new functional heart tissue would have been akin to a miracle.

Critical thinking and healthy skepticism, the scientific peer review processor and even common sense should have alerted us to the problems associated with these claims, but they all failed. Perhaps scientists, physicians and patients were so excited by the prospect of creating new heart tissue that they suspended much-needed skepticism. Exaggerated confidence in the validity of the scientific data published in highly regarded scientific journals may have played an important role. Unintentional cognitive biases of scientists who conducted the experiments and a disregard for alternative explanations could have also contributed to the propagation of ideas that would withstand subsequent testing. Scientific misconduct may also play a role. For example, the cardiologist who conducted the first clinical studies with bone marrow cell infusions in heart attack patients was investigated by his university for scientific misconduct because a review of his work had identified massive errors.

This is just one example to illustrate problems associated with an exaggerated confidence in the validity of scientific findings, a kind of confidence which scientism engenders. Such examples are by no means restricted to stem cell biology. A recent analysis of scientific reproducibility in cancer research claimed that only 11% of published cancer biology papers could be independently validated, and other areas of scientific research may be similarly afflicted by the problem of irreproducibility of published, peer-reviewed scientific papers.
Increasing numbers of scientists are recognizing that current approaches to interpreting and publishing scientific data are severely flawed. Exaggerated confidence in the validity of scientific findings is frequently misplaced and claims that scientific results represent objective truths need to be re-evaluated particularly when a high percentage of experimental results cannot be replicated by fellow scientists. In this particular context, the views of scientists who are trying to learn lessons from the failures of the scientific peer review process are not so different from those of "scientism" critics. However, many scientists, myself included, remain reluctant to use the expression "scientism".  

Rosenberg illustrates the problems associated with the word "scientism". Since "scientism" is often used as an epithet, invoking "scientism" may impede constructive discussions about the appropriateness of applying scientific methods. While a question such as "Can issues of morality be answered by scientific experiments?" may be important, introducing the term "scientism" with all its baggage distracts from addressing the question in a rational manner.
The other major issue associated with the term "scientism" is its vagueness. It is difficult to discuss "scientism" if it encompasses a broad range of distinct concepts such as the notion that science has to remain within certain boundaries as well as a criticism of overweening confidence in the validity of scientific findings. I can easily identify with asking for a realistic reappraisal of whether or not scientific results obtained by one laboratory constitute an objective, scientific truth but I am opposed to creating boundary lines that forbid certain forms of scientific inquiry because it might infringe on the domains of the humanities. Instead of the diffuse expression "scientism", I prefer the term "science mystique" to criticize the exaggerated, near-mythical confidence in the infallibility of scientific results

Rosenberg's view that the expression "scientism" and also the culture of "scientism" should be embraced received a big boost when the scientist Steven Pinker published his polemic essay "Science Is Not Your Enemy: An impassioned plea to neglected novelists, embattled professors, and tenure-less historians". Like Rosenberg, Pinker wants to rehabilitate the expression "scientism" and use it to indicate a positive, science-affirming worldview. Unfortunately, instead of engaging in a constructive dialogue about the culture of "scientism", Pinker reveals his condescending attitude towards the humanities throughout the essay. His notion of respect for the humanities consists of pointing out how much better off classical philosophers might have been if they had been aware of modern neuroscience. 

But Pinker does not comment on the converse proposition: Would scientists be better off if they knew more about philosophy? Pinker goes on to portray scientists as dynamic forward thinkers, while humanities scholars are supposedly weighed down by their intellectual inertia:
"Several university presidents and provosts have lamented to me that when a scientist comes into their office, it's to announce some exciting new research opportunity and demand the resources to pursue it. When a humanities scholar drops by, it's to plead for respect for the way things have always been done."

Pinker glosses over the reproducibility issues in science and reaffirms his faith in the current system of scientific peer review without commenting on the limitations of scientific peer review:
"Scientism, in this good sense, is not the belief that members of the occupational guild called "science" are particularly wise or noble. On the contrary, the defining practices of science, including open debate, peer review, and double-blind methods, are explicitly designed to circumvent the errors and sins to which scientists, being human, are vulnerable."
The philosopher and scientist Massimo Pigliucci wrote an excellent response to Steven Pinker, discussing the flaws inherent in Pinker's polemic and explaining why promoting a culture of scientism or a "science mystique" is not in the interest of science. I also agree with the physicist Sean Carroll who reminds us that we should get rid of the term "scientism"; not because he wants to get rid of a critical evaluation of science, but because he thinks this poorly defined term is not very helpful.

Whether or not we use the word "scientism", it is apparent that the debates between the critics and defenders of the culture of "scientism" are here to stay. It is unlikely that rehabilitating the unhelpful word "scientism" or polemical stances towards the humanities will contribute to this debate in a meaningful manner. The challenge for scientists and non-scientists is to embrace and address the legitimate criticisms of science without promoting the agenda of irrational anti-science bashing. 

Note: An earlier version of this article was first published on the 3Quarksdaily blog

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