The Scientist’s Skepticism

To honor the great philosopher of science and CSI Fellow Mario Bunge, who died February 24, 2020 (see SI, July/August 2020), we here republish one of his classic articles from Skeptical Inquirer, explaining the type of skepticism all good scientists and skeptics use. We first published it in our Summer 1992 issue, but it is just as relevant today.

Those of us who question the beliefs in ghosts, reincarnation, telepathy, clairvoyance, psychokinesis, dowsing, astral influences, magic, witchcraft, UFO-abductions, graphology, psychic surgery, homeopathy, psychoanalysis, and the like, call ourselves “skeptics.” By so doing, we wish to indicate that we adopt Descartes’s famous methodical doubt. This is just initial distrust of extraordinary perceptions, thoughts, and reports. It is not that skeptics close their minds to strange events but that, before admitting that such events are real, they want to have them checked with new experiences or reasonings. Skeptics do not accept naively the first things they perceive or think; they are not gullible. Nor are they neophobic. They are just critical; they want to see evidence before believing.

Two Kinds of Skepticism

Methodical doubt is the nucleus of methodological skepticism. This kind of skepticism must be distinguished from systematic skepticism, which denies the possibility of any knowledge and therefore entails that truth is inaccessible, and the search for it vain. The skeptics of both varieties criticize naiveté and dogmatism, but whereas methodological skepticism urges us to investigate, systematic skepticism blocks research and thereby leads to the same result as dogmatism, namely, stagnation or worse.

The craftsman and the technologist, the manager and the organizer, as well as the scientist and the authentic philosopher, behave as methodological skeptics even if they have never heard about this approach—and even if they behave naively or dogmatically after work hours. In fact, in their professional work they are not gullible, nor do they disbelieve everything, but they mistrust any important idea that has not been put to the test and demand the control of data as well as the test of conjectures. They look for new truths instead of remaining content with a handful of dogmas, but they also hold certain beliefs.

For example, the electrician makes some measurements and tests the installation before delivering it; the pharmacologist tests the new drug before advising to proceed to its manufacture in industrial quantities; the manager orders marketing research before launching a new product; the editor asks for advice of referees before sending a new work to the printer; teachers test their students’ progress before evaluating them; mathematicians attempt to prove or disprove their theorems; physicists, chemists, biologists, and psychologists design and redesign experiments by means of which they test their hypotheses; the sociologist, serious economist, and the political scientist study random samples of the populations they are interested in before announcing generalizations about them—and so on. In all these cases, people search for truth or efficiency and, far from admitting uncritically hypotheses, data, techniques, and plans, they bother to check them.

On the other hand, the theologians and school philosophers, the neoclassical economist and messianic politicians, as well as the pseudoscientists and counterculture gurus, indulge in the luxury of repeating dogmas that either are untestable or have failed rigorous tests. The rest, those of us who make a living working with our hands, producing or diffusing knowledge, organizing or managing organizations, are supposed to practice methodological doubt.

Methodological skepticism is a methodological, practical, and moral stance. Indeed, those who adopt it believe that it is foolish, imprudent, and morally wrong to announce, practice, or preach important ideas or practices that have not been put to the test or, worse, that have been shown in a conclusive manner to be utterly false, inefficient, or harmful. (Note the restriction to important beliefs; by definition, trivialities are harmless even when false.)

Because we trust research and action based on research findings, we are not systematic skeptics. We disbelieve falsity and suspend judgment concerning whatever has not been checked, but we believe, at least temporarily, whatever passed the requisite tests. At the same time, we are willing to give up whatever beliefs prove to be groundless. In sum, methodological skeptics are constructive. …

It is impossible to evaluate an idea in and by itself, independently of some system of ideas that is taken as a basis or standard. When examining any idea, we do so in the light of further ideas that we do not question at the moment; absolute doubt would be as irrational as absolute belief. Hence systematic or radical skepticism is logically untenable. By the same token, every methodological skeptic has some creed or other, however provisional it may be.

For example, we evaluate a mathematical theorem in light of its premises and the laws of logic—and in turn the latter are evaluated by their fertility and consistency with mathematics. We judge a physical theory by its logical consistency and its mathematical tidiness as well as according to its harmony with other physical theories and its correspondence with the relevant empirical data. We evaluate a chemical theory according to the physical theories it takes for granted and according to whether or not it jibes with other chemical theories as well as with the relevant experimental data. We proceed in a similar manner with the remaining sciences. In particular, we demand that psychology does not violate any biological laws and that the social sciences respect psychology and harmonize with one another. (The fact that mainstream economics and politology do not care for other social sciences is precisely a point against them.)

In other words, the scientist’s skepticism is methodological and partial, not systematic and total. Serious researchers are neither gullible nor nihilistic; they do not embrace beliefs uncritically, but do admit, at least until new notice, a host of data and theories. Their skepticism is constructive, not just critical.

Moreover, in every case the methodological skeptic presupposes—albeit seldom explicitly—that scientific theories and methods satisfy certain philosophical requirements. These are (a) materialism: everything in the universe is concrete or material, though not necessarily corporeal, and everything behaves lawfully; (b) realism: the world exists independently of those who study it, and moreover it can be known at least partially and gradually; (c) rationalism: our ideas ought to be internally consistent and they should cohere with one another; (d) empiricism: every idea about real things should be empirically testable; and (e) systemism: the data and hypotheses of science are not stray but constitute a system (for details, see Bunge 1983a, 1983b).

No doubt, few scientists realize that these five principles are indeed presupposed in scientific research. However, it does not take much to show that (a) if any of the preceding principles were relinquished, scientific research would miscarry, and (b) the main difference between science and pseudoscience is not so much that the former is true and the latter false, but that pseudoscience does not abide by those principles—as a consequence of which it seldom delivers truth and it never corrects itself.

Not all skeptics share these philosophical principles. Most of them believe that only scientific method applied to data-gathering is required to conduct scientific research. However, it is possible to apply the scientific method to a nonscientific investigation, such as trying to measure the speed of ghosts or the intensity of the action of mind on matter. To yield knowledge, the scientific method must be accompanied by a scientific worldview: materialist, realist, rationalist, empiricist, and systemic. This is the core of the skeptic’s credo.

Conclusion

Methodological skeptics are not gullible, but they do not question everything at once either. They believe whatever has been demonstrated or has been shown to have strong empirical support. They disbelieve whatever clashes with logic or with the bulk of scientific knowledge and its underlying philosophical hypotheses. Theirs is a qualified, not indiscriminate skepticism.

The methodological skeptics uphold many principles and, above all, they trust humans to advance even further in the knowledge of reality. Their faith is critical, not blind; it is the explorer’s faith, not the believer’s. They do not believe anything in the absence of evidence, but they are willing to explore bold new ideas if they find reasons to suspect that they have a chance (see, for example, Bunge 1983c). They are open-minded but not blank-minded; they are quick to filter out intellectual rubbish.

For example, methodological skeptics find no reason to engage in experimental investigations before denying that pure thought may energize machines, that surgery can be performed by sheer mental power, that magical incantations or solutions of one part in ten raised to the 100th power have therapeutic power, that perpetual-motion machines can be built, or that there are solve-all theories. All such beliefs can be demolished by wielding some well-tested scientific or philosophical principles. This strategy is certainly cheaper than naive empiricism.

To conclude: Pseudoscience and pseudotechnology are the modern versions of magical thinking. They must be subjected to critical scrutiny not only to clean up culture but also to prevent quacks from cleaning out our pockets. And to criticize them it is not enough to show that they lack empirical support—for, after all, one might believe that such support could be forthcoming. We must also show that those beliefs in the arcane or the paranormal clash with either well-established scientific theories or fertile philosophical principles. For this reason, the criticism of magical thinking should be a common endeavor of scientists, technologists, philosophers, and educators. Given the massive commercial exploitation of junk culture, as well as the current decline in the teaching of science and technology in numerous countries, unless we work harder on debunking pseudoscience and pseudotechnology, we shall be in for a sharp decline of modern civilization (Bunge 1989).

References

Bunge, M. 1983a. Exploring the World. Dordrecht, The Netherlands: Reidel
_______. 1983b. Understanding the World. Dordrecht, The Netherlands: Reidel.
_______. 1983c. Speculation: Wild and sound. New Ideas in Psychology 1: 3–6.
________. 1989. The popular perception of science in North America. Transactions of the Royal Society of Canada, ser. V, 4: 269–280.

Mario Bunge

Mario Bunge, who died in February 2020 at the age of 100, was both a physicist and a philosopher. He spent many decades in the Foundations and Philosophy of Science Unit at McGill University in Montreal. This article was excerpted by permission from “A Skeptic’s Beliefs and Disbeliefs,” the lead article of a special issue of New Ideas in Psychology devoted to “Mario Bunge on Nonscientific Psychology and Pseudoscience: A Debate” (vol. 9, no. 2, 1991). That journal’s editor at the time, Pierre Moessinger, wrote in a leadoff editorial, “Mario Bunge is one of the few great philosophers of science of our times. More precisely he is both a philosopher and a scientist. … What is so extraordinary about Bunge is the breadth of his intellectual interests and his ability to coordinate and synthesize problems.” Bunge’s paper was originally presented at a CSICOP conference on “Magical Thinking and Its Prevalence in the World Today” in Mexico City in 1989. Bunge was a longtime CSICOP/ CSI fellow and frequent contributor to Skeptical Inquirer.