Massimo Pigliucci is an evolutionary biologist, philosopher, professor, and noted skeptic and author. He is also almost the same age as I am, but I’m trying not to let that ruin my day. His most recent book is Nonsense on Stilts: How to tell science from bunk.
There are many cogent arguments in this book which are relevant and useful for distinguishing between scientific and unscientific or pseudoscientific approaches to medicine, a major goal of this blog. In particular, I found Dr. Pigliucci’s response to postmodernist critiques of science and his discussion of the subject of expertise compelling and enlightening. There are also, however, many other subjects which are interesting in themselves but do not relate directly to the distinction between science and non-science. I began the book with the misapprehension, based on the title and some elements of the advertising and the introduction, that it was intended to be primarily about defining science and distinguishing it from non-science and especially from pseudoscience, which is what I take “bunk” to mean in this context. However, the books reads a bit more like a collection of loosely related essays than a structured argument. The back cover is only half right in that the subject matter is not really a “taxonomy of bunk,” as it is described, but it is an exploration of “the intersection of science and culture at large.”
I will briefly summarize the main points of each section of the book, partly to give a feel for its contents and also to point out those sections that relate to core issues this blog is concerned with. It should be taken as a given that the book itself is far more detailed and nuanced than my attempts to summarize, and that since much of it is well outside my own areas of expertise I may very well unintentionally misrepresent Dr. Pigliucci’s arguments. Since this review is more than long enough by itself, I intend to extract a few specific arguments from the book as subjects for separate posts.
Dr. Pigliucci begins by introducing the “demarcation problem,” the difficulty in distinguishing science from non-scientific or pseudoscientific approaches. He dismisses the popular notion, generally credited to Karl Popper, that science is distinguished primarily by falsifiability, that is one can tell a scientific explanation from a non-scientific one because the former contains criteria by which it can be disproved and the latter does not. I gather from the book that this idea is quite passé in the philosophy of science. But as Pigliucci points out, it is still quite popular among scientists and skeptics, so I would have appreciated a more thorough explanation of why it is inadequate before he moves on to alternative ways of understanding what science is.
The first chapter challenges the usual distinction between so-called “hard” sciences, such as physics, and “soft” sciences like psychology. Pigliucci contends that these two types of scientific endeavor are not really distinguished by the quality, precision, or accuracy of their data but by the degree to which they are predictive or historical. The branches of science usually understood as “hard” are very good at measurement and prediction within controlled conditions but weaker at accounting for more complex “real world” events. The historical sciences, by contrast, can often convincingly explain past events but are not every effective at prediction.
I’m not entirely convinced by this characterization, nor do I see exactly how it leads to what seems to be the main conclusion of this chapter, which is that both approaches deserve the label “science” because they share “the ability to produce and test hypotheses based on systematically collected empirical data (via experiments or observations.)” He returns to this definition in his conclusions, where he defines science this way:
…an investigation of nature, based on the construction of empirically verifiable theories and hypotheses. These three elements, naturalism, theory, and empiricism are what make science different from any other human activity.
This seems a pretty reasonable approach to characterizing science as an intellectual and social endeavor. I’m not entirely sure that the book clearly and logically builds up to this definition, so it seems to appear a bit mysteriously at the beginning and the end and in several places between. This may be my own lack of sophistication in following Dr. Pigliucci’s arguments, but again my impression is that the book is an interesting but meandering stroll through issues associated with science and other elements of culture rather than a forceful linear argument leading up to a final conclusion about what is and is not science.
The next chapter gives several examples of “almost science,” areas of theorizing and research which Dr. Pigliucci doesn’t feel reach the level of full science. The main subjects he uses as examples are string theory and the multiple worlds interpretation of quantum mechanics, the Search for Extraterrestrial Intelligence (SETI), and evolutionary psychology. The first apparently fails the test of empiricism in that the hypotheses these theories generate are not yet testable. SETI is characterized as not entirely scientific because it appears not to be falsifiable (negative findings are expected most of the time, so while a single positive finding would justify the endeavor, no number of negative findings could prove the whole thing a waste of time) and because its theoretical foundations are judged weak. Evolutionary psychology as applied to humans is judged insufficiently testable to be solidly scientific, though it may be true science when applied to species which can be observed and manipulated sufficiently to validate or falsify specific hypotheses.
It is clear that Dr. Pigliucci is taking great pains to avoid an overly simplistic application of his defining criteria. He repeatedly reminds the reader that these “almost sciences” are not equivalent to outright pseudosciences like astrology and creationism. Yet there seems to be a degree of subtlety and subjectivity to his assessments that make the value of the whole category of “almost science” a bit questionable. If there are sufficient shades of gray between (almost) universally accepted “real” science on the one hand and (almost) universally accepted non-science on the other, than some significant segment of the continuum in between simply cannot be reliably assessed as science or not science. This may be the intrinsic nature of messy reality, but if our goal is to distinguish science from non-science for important practical reasons, too much nuance and ambiguity undermine that goal.
This is similar to the problem of the reliability of scientific conclusions. It is true, of course, that scientific truths are inherently probabilistic and provisional. But it is also true that once a certain degree of confidence in an idea can be justified by sufficient evidence, doubting such an idea becomes irrational and skepticism becomes willful denialism. In trying to avoid an overly simplistic and rigid set of criteria and in recognizing the inevitable uncertainties in all knowledge, I think Pigliucci sometimes is too careful and undermines the utility of his own, quite reasonable and otherwise useful approach to defining science.
In the next chapter, Dr. Pigliucci discusses several examples of pseudoscience, included HIV/AIDS denialism, astrology, UFOs, and the investigation of paranormal phenomena. While he does a variable job of illustrating why the specific examples are untrue (dissecting astrology in detail but talking mostly about the consequences rather than the factual falsity of AIDS denialism), and he covers many of the usual reasons why people believe in pseudoscience, he doesn’t really use these examples to illustrate a general thesis or approach to identifying pseudoscience and distinguishing it from science.
The next several chapters are interesting in themselves, though again they really read as a loosely connected set of essays on the relationship between science and society. He discusses how the media (mis)portrays science and scientific information, he talks about the character of the public intellectual and its role in society, he discussed science and politics through the climate change debate, and he looks at the relationship of science and the courts through the example of the intelligent design movement.
There then follows a brief history, in two chapters, of the development of those elements of philosophy that relate to, and eventually become, science. I found this section fascinating, and I enjoyed seeing the development of core ideas underlying modern science portrayed as a historical narrative.
The next three chapters are by far my favorites, and they deal with the subject of expertise, and with the complex but critical issue, from the point of view of science-based medicine, of how we acknowledge the limitations of science and guard against them while at the same time not abandoning science and reason altogether and simply accepting a faith-based approach to knowledge or an epistemologically nihilistic approach like that of extreme postmodernism that says no knowledge is possible. I will be examining Pigliucci’s arguments and conclusions in detail in a future post, because I think he very effectively addresses these issues and points the way to a reconciliation and synthesis that is very useful.
Though I began Dr. Pigliucci’s book with a bit of a misconception of what he was setting out to accomplish, and consequently found only a few sections of it directly applicable to my interest in understanding the distinction between science and non-science, I still found the book interesting and informative. His prose is quite readable, even when dealing with complex issues. I might have preferred a bit less qualification in some areas, but I respect his efforts to present complex and nuanced issues honestly and without oversimplification. Overall, I certainly recommend Nonsense on Stilts.