The Scientist's Skepticism MARIO BUNGE

hose of us who question the beliefs in ghosts, reincarnation, telepathy, clair- Tvoyance, 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 There are two that, before admitting that such events are real, they want to have them checked with new kinds of experiences or reasonings. Skeptics do not skepticism. Only accept naively the first things they perceive or think; they are not gullible. Nor are they one is part of the neophobic. They are just critical; they want to scientific outlook. 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 naivete 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 scien- tist 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

Summer 1992 377 are not gullible, nor do they disbelieve Methodological skepticism is a everything, but they mistrust any methodological, practical, and moral important idea that has not been put stance. Indeed, those who adopt it to the test and demand the control of believe that it is foolish, imprudent, data as well as the test of conjectures. and morally wrong to announce, They look for new truths instead of practice, or preach important ideas or remaining content with a handful of practices that have not been put to dogmas, but they also hold certain the test or, worse, that have been beliefs. shown in a conclusive manner to be For example, the electrician makes utterly false, inefficient, or harmful. some measurements and tests the (Note the restriction to important installation before delivering it; the beliefs; by definition, trivialities are pharmacologist tests the new drug harmless even when false.) before advising to proceed to its Because we trust research and manufacture in industrial quantities; action based on research findings, we the manager orders marketing are not systematic skeptics. We dis- research before launching a new believe falsity and suspend judgment product; the editor asks for advice of concerning whatever has not been referees before sending a new work checked, but we believe, at least tem- to the printer; teachers test their porarily, whatever passed the requi- students' progress before evaluating site tests. At the same time, we are them; mathematicians attempt to willing to give up whatever beliefs prove or disprove their theorems; prove to be groundless. In sum, physicists, chemists, biologists, and methodological skeptics are construc- psychologists design and redesign tive. . . . experiments by means of which they test their hypotheses; the sociologist, The Scientist's Skepticism the serious economist, and the political scientist study random samples of the It is impossible to evaluate an idea in populations they are interested in and by itself, independently of some before announcing generalizations system of ideas that is taken as a basis about them—and so on. In all these or standard. When examining any idea cases people search for truth or we do so in the light of further ideas efficiency and, far from admitting that we do not question at the uncritically hypotheses, data, tech- moment; absolute doubt would be as niques, and plans, they bother to check irrational as absolute belief. Hence them. systematic or radical skepticism is On the other hand, the theologians logically untenable. By the same and school philosophers, the neoclas- token, every methodological skeptic sical economists and messianic politi- has some creed or other, however pro- cians, as well as the pseudoscientists visional it may be. and the counterculture gurus, indulge For example, we evaluate a mathe- in the luxury of repeating dogmas that matical theorem in the light of its either are untestable or have failed premises and the laws of logic—and rigorous tests. The rest, those of us in turn the latter are evaluated by their who make a living working with our fertility and consistency with mathe- hands, producing or diffusing knowl- matics. We judge a physical theory by edge, organizing, or managing organ- its logical consistency and its mathe- izations, are supposed to practice matical tidiness as well as according methodological doubt. to its harmony with other physical

378 SKEPTICAL INQUIRER, Vol. 16 theories and its correspondence with the relevant empirical data. We eval- uate a chemical theory according to "Methodological skeptics are not the physical theories it takes for gullible, but they do not granted and according to whether or not it jibes with other chemical question everything at once theories as well as with the relevant either. . . . Theirs is a experimental data. We proceed in a similar manner with the remaining qualified, not indiscriminate sciences. In particular, we demand that skepticism." psychology does not violate any biological laws and that the social sciences respect psychology and har- presupposed in scientific research. monize with one another. (The fact However, it does not take much to that mainstream economics and poli- show that (a) if any of the preceding tology do not care for other social principles were relinquished, scientific sciences is precisely a point against research would miscarry, and (b) the them.) main difference between science and In other words, the scientist's pseudoscience is not so much that the skepticism is methodological and former is true and the latter false, but partial, not systematic and total. that pseudoscience does not abide by Serious researchers are neither gul- those principles—as a consequence of lible nor nihilistic; they do not embrace which it seldom delivers truth and it beliefs uncritically, but do admit, at never corrects itself. least until new notice, a host of data Not all skeptics share these philo- and theories. Their skepticism is sophical principles. Most of them constructive, not just critical. believe that only scientific method Moreover, in every case the meth- applied to data-gathering is required odological or moderate skeptic presup- to conduct scientific research. How- poses—albeit seldom explicitly—that ever, it is possible to apply the scien- scientific theories and methods satisfy tific method to a nonscientific certain philosophical requirements. investigation, such as trying to mea- These are (a) materialism: everything sure the speed of ghosts or the in the universe is concrete or material, intensity of the action of mind on though not necessarily corporeal, and matter. To yield knowledge, the scien- everything behaves lawfully; (b) real- tific method must be accompanied by ism: the world exists independently of a scientific world-view: materialist, those who study it, and moreover it realist, rationalist, empiricist, and can be known at least partially and systemic. This is the core of a skeptic's gradually; (c) rationalism: our ideas credo. ought to be internally consistent and they should cohere with one another; Conclusion (d) empiricism: every idea about real things should be empirically testable; Methodological skeptics are not gul- and (e) systemism: the data and hy- lible, but they do not question every- potheses of science are not stray but thing at once either. They believe constitute a system (for details, see whatever has been demonstrated or Bunge 1983a, 1983b). has been shown to have strong No doubt, few scientists realize empirical support. They disbelieve that these five principles are indeed whatever clashes with logic or with

Summer 1992 379 the bulk of scientific knowledge and ing should be a common endeavor of its underlying philosophical hypoth- scientists, technologists, philosophers, eses. Theirs is a qualified, not in- and educators. Given the massive discriminate skepticism. commerical exploitation of junk cul- The methodological skeptics ture, as well as the current decline in uphold many principles and, above all, the teaching of science and technology they trust humans to advance even in numerous countries, unless we further in the knowledge of reality. work harder on debunking pseudo- Their faith is critical, not blind; it is science and pseudotechnology we the explorer's faith not the believer's. shall be in for a sharp decline of They do not believe anything in the modern civilization (see Bunge 1989). absence of evidence, but they are willing to explore bold new ideas if References they find reasons to suspect that they have a chance (see, for example, Bunge Bunge, M. 1983a. Exploring the World. 1983c). They are open-minded but not Dordrecht: Reidel. blank-minded; they are quick to filter . 1983b. Understanding the World. Dordrecht: Reidel. out intellectual rubbish. . 1983c. Speculation: Wild and sound. For example, methodological skep- New Ideas in Psychology, 1:3-6. tics find no reason to engage in . 1989. The popular perception of science in North America. Transactions of experimental investigations before the Royal Society of Canada, ser. V, 4:269- denying that pure thought may ener- 280. gize machines, that surgery can be performed by sheer mental power, Mario Bunge is in the Foundations and that magical incantations or solutions Philosophy of Science Unit, McGill of one part in ten raised to the 100th University, Montreal, H3A lW7, power have therapeutic power, that Canada. This article is excerpted by perpetual-motion machines can be permission from the opening and conclud- built, or that there are solve-all ing sections of "A Skeptic's Beliefs and theories. All such beliefs can be Disbeliefs," the lead article of a special demolished by wielding some well- issue of New Ideas in Psychology (vol. tested scientific or philosophical 9, no. 2, 1991, Pergamon Press) devoted principles. This strategy is certainly to "Mario Bunge on Nonscientific cheaper than naive empiricism. Psychology and Pseudoscience: A Debate." To conclude. Pseudoscience and That journal's editor, Pierre Moessinger, pseudotechnology are the modern in a leadoff editorial about its first special versions of magical thinking. They issue, says: "Mario Bunge is one of the must be subjected to critical scrutiny few great philosophers of science of our not only to clean up culture but also times. More precisely, he is both a to prevent quacks from cleaning out philosopher and a scientist. . . . What our pockets. And to criticize them it is so extraordinary about Bunge is the is not enough to show that they lack breadth of his intellectual interests and his empirical support—for, after all, one ability to coordinate and synthesize might believe that such support could problems. ..." Bunge's paper was be forthcoming. We must also show originally given as the Keynote Address that those beliefs in the arcane or in at the CSICOP conference on "Magical the paranormal clash with either well- Thinking and Its Prevalence in the World established scientific theories or fertile Today," held at the Universidad Nacional philosophical principles. For this Autonoma de Mexico City, November 10, reason, the criticism of magical think- 1989. Bunge is a CSICOP Fellow.

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