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Should Skeptical Inquiry Be Applied to Religion?


Paul Kurtz

Skeptical Inquirer Volume 23.4, July / August 1999

Skeptical inquirers can and should examine religious claims, though the case can be made that CSICOP should not.

Scientific Inquiry

The relationship between science and religion has engendered heated controversy. This debate has its roots in the historic conflict between the advocates of reason and the disciples of faith. On the current scene, there is a vocal hallelujah chorus singing praises to the mutual harmony and support of these two realms or “magisteria.” I have serious misgivings about this alleged rapprochement, but I wish to focus on only one aspect of the controversy, and ask: To what extent should we apply skepticism to religious claims?

By the term “skepticism” I do not refer to the classical philosophical position which denies that reliable knowledge is possible. Rather, I use the term "skepticism” to refer to skeptical inquiry. There is a contrast between two forms of skepticism, (1) that which emphasizes doubt and the impossibility of knowledge, and (2) that which focuses on inquiry and the genuine possibility of knowledge; for this latter form of skepticism ("the new skepticism,” as I have labeled it),1 skeptical inquiry is essential in all fields of scientific research. What I have in mind is the fact that scientific inquirers formulate hypotheses to account for data and solve problems; their findings are tentative; they are accepted because they draw upon a range of confirming evidence and predictions and/or fit into a logically coherent theoretical framework. Reliable hypotheses are adopted because they are corroborated by a community of inquirers and because the tests that confirm them can be replicated. Scientific hypotheses and theories are fallible; and in principle they are open to question in the light of future discoveries and/or the introduction of more comprehensive theories. The point is that we have been able to achieve reliable knowledge in discipline after discipline because of the effective application of skeptical inquiry.

Now the central questions that have been raised concern the range of skeptical inquiry. Are there areas such as religion in which science cannot enter? In particular, Should the skeptical movement extend its inquiry to religious questions? Some influential skeptics think we should not. In my view, skeptical inquirers definitely need to investigate religious claims. I do not think that CSICOP and the Skeptical Inquirer, however, should deal with religious claims; or if they do so, it should be only in a limited way. I shall deal with my reasons for these perhaps surprising statements later in this article.

Science has always had its critics, who have insisted that one or another area of human interest is immune to scientific inquiry. At one time it was proclaimed that astronomers could never know the outermost reaches of the universe (August Comte), the innermost nature of the atom (John Locke), or human consciousness (Henri Bergson). Critics have also insisted that we could not apply science to one or another aspect of human experience-political, economic, social, or ethical behavior, the arts, human psychology, sexuality, or feeling. I do not think that we should set a priori limits antecedent to inquiry; we should not seek to denigrate the ability of scientific investigators to explain behavior or to extend the frontiers of research into new areas.

Can There Be a Science of Religion?

Some have argued that religious phenomena-matters of faith-are entirely beyond the ken of science; but this surely is false because the scientific investigation of religion has already made great strides and there is a vast literature now available. We may talk about religion in at least two senses: First, religion refers to a form of human behavior that can be investigated. Second, it is used to refer to the transcendental, i.e., to that which transcends human experience or reason.

Let us turn to the first area. Religious behavior has been investigated by a wide range of disciplines: Anthropologists deal with the comparative study of primitive religions, examining prayer, ritual, the rites of passage, etc. Sociologists have investigated the institutional aspects of religious behavior, such as the role of the priestly class in society. Ever since William James, psychologists of religion have studied the varieties of religious experience, such as mysticism, ecstasy, talking in tongues, exorcism, etc. Similarly, biologists have postulated a role for religious beliefs and practices in the evolutionary process and their possible adaptive/survival value. They have asked, Does religiosity have a genetic or environmental basis? Others have focused on the neurological correlates of religious piety, and still others have attempted to test the efficacy of prayer.

One can deal with religion in contemporary or historical contexts. A great deal of attention has been devoted to the historical analysis of religious claims, especially since the great classical religions are based on ancient documents (the Old and New Testaments and the Koran), as are some of the newer religions (such as the nineteenth-century Book of Mormon). These texts allege that certain miraculous and revelatory events have occurred in the past and these warrant religious belief today; and it is often claimed that belief in them is based upon faith.

I would respond that scientific methodology has been used in historical investigations to examine these alleged events. Archaeologists seek independent corroborating evidence; they examine written or oral accounts that were contemporaneous with the events (for example, by comparing the Dead Sea Scrolls with the New Testament). The fields of “biblical criticism” or “koranic criticism” have attempted to use the best scholarly techniques, historical evidence, and textual and linguistic analysis to ascertain the historical accuracy of these claims.

Paranormal claims are similar to religious claims-both purport to be exceptions to natural laws. Skeptics have asked: Did D.D. Home float out of a window and levitate over a street in London in the late nineteenth century? Did the Fox sisters and Eusapia Palladino possess the ability to communicate with the dead? And they have sought to provide naturalistic interpretations for reports of bizarre events. No doubt it is easier to examine contemporaneous claims where the record is still available rather than ancient ones where the record may be fragmentary. Yet in principle at least, the religious investigator is similar to the paranormal investigator, attempting to ascertain the accuracy of the historical record. We use similar methods of inquiry to examine prosaic historical questions, such as: Did Washington cross the Delaware, or Thomas Jefferson sire the children of Sally Heming? The same goes for religious claims: Did the Red Sea part before the fleeing Hebrews, was there a Great Flood and a Noah’s Ark? I don't see how or why we should declare that these historical religious claims are immune to scientific investigation.

Thus I maintain that insofar as religion refers to a form of human behavior, whether in the past or the present, we can, if we can uncover corroborating data or historical records, attempt to authenticate the historical claims and ask whether there were paranormal, occult, or transcendental causes, or whether naturalistic explanations are available. David Hume’s arguments against miracles indicate all the reasons why we should be skeptical of ancient claims-because they lack adequate documentation, because the eyewitnesses were biased, and so on. And this should apply, in my view, to reports of revelation as well as miracles. Extraordinary claims that violate naturalistic causal regularities should require strong evidence. I don't see how anyone can protest that his beliefs ought to be immune to the standards of objective historical investigation, simply by claiming that they are held on the basis of faith. A good case in point is the alleged burial shroud of Jesus, the Shroud of Turin. Meticulous carbon-14 dating by three renowned laboratories has shown that the cloth is approximately 700 years old and therefore most likely a forgery. The fact that believers may seek to shield their belief by proclaiming that they have faith that the Shroud is genuine does not make it any more true. The same principle applies to the key miraculous revelations of the past upon which the classical religions are allegedly based. The strength of a hypothesis or belief should be a function of the empirical evidence extant brought to support it, and if the evidence is weak or spotty, then the faith claim should likewise be so regarded.

Religious belief systems are deeply ingrained in human history, culture, and social institutions that predate science, and thus it is often difficult, if not impossible, to insist upon using the standards of objective skeptical inquiry retrospectively. This is especially the case since to believe in a religion is more than a question of cognitive assent, for religion has its roots in ethnic or national identity; and to question the empirical or rational grounds for religious belief is to shake at the very foundations of the social order.

How to Deal with the Transcendental?

There is a second sense of religion that is nonbehavioral. Here the key question concerns the very existence of a “transcendental, supernatural, occult, or paranormal realm” over and beyond the natural world. The scientific naturalist argues that we should seek natural causes and explanations for paranormal and religious phenomena, that we should never abandon scientific methodology, and that we should endeavor totest all claims by reference to justifying evidence and reasons.

We may ask, What is the truth value of theistic claims? In the great debate between scientific or philosophical skeptics and theists, agnostics/nontheists/atheists maintain that theists have not adequately justified their case and that their claims are unlikely or implausible. I will not here review the extensive classical argument or the kinds or evidence adduced.

I do wish, however, to focus on one point that has recently emerged in the literature. And this concerns a prior question raised by analytic philosophers about the meaning of “God language.” Any scientific inquiry presupposes some clarity about the meaning of its basic terms. Is religious language to be taken literally, descriptively, or cognitively; and if so, are we prepared to assert that there is some “transcendental ground, cause, creator, or purpose” to the universe? Most linguistic skeptics have sought to deconstruct religious language and have had difficulty in determining precisely to what the terms "God” or “divinity” or “transcendental being” refer. Similarly for the vague, often incoherent, use of the term “spirituality,” so popular today. They appear to be indefinable, even to theologians, and hence before we can say whether He, She, or It exists, we need to know precisely what is being asserted. Most God talk is nonfalsifiable, in that we would not know how to confirm or disconfirm any claim about His presence or existence. God talk is by definition difficult or impossible insofar as it transcends any possible experience or reason and lurks in a mysterious noumenal realm. There are surely many things that we do not know about the universe; but to describe the unknown as “divine” is to take a leap of faith beyond reasonable evidence.

Linguistic skeptics have held that if we are to make sense of religious language, we must recognize that it has other nondescriptive or noncognitive functions. It does not convey us truth about the world (thus competing with science or ordinary experience), but is evocative, expressive, or emotive in character, or is performatory and celebrative in a social context, or is moral in its imperative function, or it has poetic metaphorical meaning. Thus God talk should be construed primarily as a form of personal and social moral poetry. If this is the case, then religion does not give us knowledge or truth; instead it expresses mood and attitude.

I am not talking about the historical truth of Jesus’ alleged resurrection or Joseph Smith’s encounter with the angel Moroni or Mohammed’s communication with Gabriel-these are concrete historical claims and in principle at least are available to empirical and rational inquiry and have some experiential content (even though the evidence may be fragmentary or incomplete), but of “divinity” viewed outside of history as a transcendental being or spiritual reality. It is the latter that is incomprehensible almost by definition.

Thus religion should not compete with science about the description and explanation of natural processes in the universe. Science deals most effectively with these questions, not religion. To claim to believe in the theory of evolution, and yet insist the “human soul” is an exception to evolutionary principles because it is created by a deity, is an illegitimate intrusion of an occult cause. Similarly, to seek to transcend the “big bang” physical theory in science by postulating a creator is to leap beyond the verifiable evidence. To say that this is justified by faith is, in my judgment, unwarranted-the most sensible posture to adopt here is that of the agnostic.

In the last analysis, religion and science are different forms of human behavior and have different functions. We may analogically ask, What is the relationship between science and sports, or science and music? These are different forms of experience, and they play different roles in human behavior. Surely neither sports nor music compete in the range of truth claims. In this sense, religion should not be taken as true or false, but as evocative, expressive, uplifting, performatory, good or bad, beautiful or ugly, socially unifying or disruptive. Historically, the claims of religion were taken as true, but this was a prescientific posture drawing upon myth and metaphor, metaphysics and speculation, not testable claims. Thus “religious truth” cannot be appealed to in order to contest the verified findings of the sciences.

I should add that I do not believe that ethics need be based on religious faith either. To maintain that the proper or exclusive role of religion is within the realm of morality (or meaning) is, I think, likewise questionable, particularly when we examine the concrete ethical recommendations made about sexual morality, divorce, abortion, euthanasia, the role of women, capital punishment, etc. This is all the more so, given the fact that religions often disagree violently about any number of moral principles. I believe that there are alternative humanistic and rational grounds for ethical judgment, based in part on scientific knowledge, but that is a topic for another paper.

Skeptical Inquiry and Religion

The key question that I wish to address is, Should skeptical inquirers question the regnant sacred cows of religion? There are both theoretical and prudential issues here at stake. I can find no theoretical reason why not, but there may be practical considerations. For one, it requires an extraordinary amount of courage today as in the past (especially in America!) to critique religion. One can challenge paranormal hucksters, mediums, psychics, alternative therapists, astrologers, and past-life hypnotherapists with abandon, but to question the revered figures of orthodox religion is another matter, for this may still raise the serious public charge of blasphemy and heresy; and this can be dangerous to one’s person and career-as Salman Rushdie’s fatwah so graphically demonstrates.

History vividly illustrates the hesitancy of skeptics to apply their skepticism to religious questions. In ancient Rome, Sextus Empiricus, author of Outlines of Pyrrhonism, defended the suspension of belief in regard to metaphysical, philosophical, and ethical issues. He did not think that reliable knowledge about reality or ethical judgments was possible. He neither affirmed nor denied the existence of the Gods, but adopted a neutral stance. Since there was no reliable knowledge, Pyrrho urged that compliance with the customs and religion of his day was the most prudent course to follow. The great skeptic Hume bade his friend, Adam Smith, to publish his iconoclastic Dialogues Concerning Natural Religion after his death (in 1776), but Smith declined to do so, disappointing Hume. Hume’s nephew David arranged for posthumous publication. The French author Pierre Bayle (1647-1706), perhaps expressed the most thoroughgoing skepticism of his time. In his Dictionnaire historique et critique, Bayle presented a scathing indictment of the prevailing theories of his day, finding them full of contradictions. He was highly critical of religious absurdities. He maintained that atheists could be more moral than Christians, and that religion did not necessarily provide a basis for ethical conduct. Nonetheless, Bayle professed that he was a Christian and a Calvinist, and this was based upon pure faith, without any evidence to support it-this is known as fideism. Did Bayle genuinely hold these views, or was his fideism a ruse to protect his reputation and his fortune?

This form of fideism, I maintain, on theoretical grounds is illegitimate, even irrational. For if, as skeptical inquirers, we are justified in accepting only those beliefs that are based upon evidence and reason, and if there is no evidence either way or insufficient evidence, should we not suspend judgment, or are we justified in taking a leap of faith? If the latter posture of faith is chosen, one can ask, On what basis? If a person is entitled to choose to believe whatever he or she wishes, solely or largely because of personal feeling and taste, then “anything goes.” But this anarchic epistemological principle can be used to distort honest inquiry. (The implication of this argument is that if we do not have a similar feeling, we are entitled not to believe.) One may ask, Can one generalize the epistemological rule, and if so, can it apply to paranormal claims? Is someone thus entitled to believe in UFO abductions, angels, or demons on the basis of feeling and fancy? The paranormal skeptic retort is that where there is evidence to decide the question, we are not justified in believing; though in a democracy we are not entitled to expect others to share our skepticism.

But as a matter of fact, most of those who believe in the traditional religions do not base it on pure fideism alone, but on reasons and evidence. Indeed, no less an authority than Pope John Paul II maintained the same in a recent encyclical entitled “Faith and Reason.” In this, the Pope condemns both fideism and atheism. He attacks the naive faith in “UFOs, astrology, and the New Age.” He criticizes “exaggerated rationalism” and pragmatism on the one hand and postmodernism on the other, but he also condemns the exclusive reliance on faith. The Pope maintains that reason and scientific inquiry support rather than hinder faith in Christian revelation and Catholic doctrine. Skeptics might agree with the Pope’s defense of reason and scientific inquiry, but question whether these do indeed support his own beliefs.

Thus, in my judgment, acquiescence by skeptics to the fideist’s rationalization for his beliefs is profoundly mistaken. Similarly, in answer to those theists who maintain that there is adequate evidence and reasons for their belief, skeptical inquirers should not simply ignore their claims, saying that they are beyond scientific confirmation, but should examine them. Since the burden of proof is always upon the claimant, skeptical inquirers may question both the fideist and the partial-evidentialist in religion, if they do not believe that they have provided an adequate justified case.


The upshot of this controversy, in my judgment, is that scientific and skeptical inquirers should deal with religious claims. Not to do so is to flee from an important area of human behavior and interest and is irresponsible. Indeed, one reason why paranormal beliefs are so prominent today is because religious beliefs are not being critically examined in the marketplace of ideas.

As I have said, I do not believe, however, that CSICOP or the Skeptical Inquirer should in any way, except tangentially, deal with religious issues. But my reasons are pragmatic, not theoretical. It is simply a question of the division of labor. We lack the resources and expertise to focus on the entire range of scientific questions about religion: biblical archaeological, biblical and koranic criticism, linguistics, psychology, anthropology, sociology, the genetic or environmental roots of religion, etc. It would take us too far afield. We have focused on fringe science and specialized in the paranormal, and we have made important contributions here. Skeptical inquiry in principle should apply equally to economics, politics, ethics, and indeed to all fields of human interest. Surely we cannot possibly evaluate each and every claim to truth that arises. My reasons are thus practical.

But at the same time I disagree with those who counsel caution in applying scientific skepticism to the religious domain. In my view science should not be so narrowly construed that it only applies to experimental laboratory work; it should bring in the tools of logical analysis, historical research, and rational investigation. In this sense, I submit, religious claims are amenable to scientific examination and skeptical inquiry.

It is possible for a scientist to apply skeptical, scientific inquiry to his or her own specialty with considerable expertise; yet he or she may not be qualified to apply the same methods of rational inquiry to other fields, and indeed may harbor religious beliefs that lack evidential support. Although disbelief about religious claims is higher among scientists (an estimated 60 percent) than the general population (perhaps 10 percent), some scientists fail to rigorously examine their own religious beliefs. They may use rigorous standards of inquiry in their particular fields of expertise, yet throw caution to the wind when they leap into questions of religious faith.

One last issue: to claim that skepticism is committed only to “methodological naturalism” and not scientific naturalism (which sums up the evidence for the naturalistic world view and critiques the theistic/spiritualistic leap beyond) is, I think, profoundly mistaken. To adopt this neutral stance in the current cultural milieu is a cop-out; for questionable religious claims are proliferating daily and they are not adequately evaluated by skeptical scientists. In my view, we need more skeptical inquirers who possess the requisite expertise and are able to apply their investigative skills to religious claims. Such skeptical inquiry is sorely needed today. It could play a vital role in the debate between religion and science.


  1. Paul Kurtz, The New Skepticism: Inquiry and Reliable Knowledge (Amherst, N.Y.: Prometheus Books, 1992).

Paul Kurtz

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Professor Paul Kurtz is the founder of the Center for Inquiry, CFI's former chairman, the former Editor-in-Chief of Free Inquiry magazine, and professor emeritus of philosophy at the State University of New York at Buffalo. Kurtz has spent much of his life on the critical examination of religion, but believes that naturalists need to emphasize and build positive alternatives to religion. For Kurtz, it is not enough to reject God, but to affirm the positive implications of the secular humanist perspective.