Home » Library » Modern Library » Michael Martin Induction

Michael Martin Induction

Does Induction Presume the Existence of the Christian God? (1997)

Michael Martin


[The following article was originally published in Skeptic, Vol. 5, #2, pp. 71-75.]

Readers of this journal may have heard of the Cosmological, the Teleological, and the Ontological Arguments for the existence of God. Indeed, many readers will know the basic problems with these traditional arguments and be able to hold their own in debates with theists when these arguments are raised. Some readers of this journal will also be acquainted with other arguments for the existence of God and the problems with them: for example, the argument from miracles and the argument from religious experience. But what about The Transcendental Argument for the Existence of God (TAG)–the argument that logic, science, and objective ethical standards presuppose the existence of God? It is likely that few, if any, readers will have heard of this argument. Indeed, it is probably not even known to most believers. Nor, to my knowledge, has it been critically evaluated in the standard philosophy of religion literature.

Ignorance of TAG is hardly surprising since it plays no role in the position of the most famous contemporary religious apologists and is not covered in standard texts in the philosophy of religion. In fact, I myself was unaware of it when I published a book on atheism in which I spend hundreds of pages refuting theistic arguments (Martin, 1990).

TAG is used by a small group of Christian apologists operating within the Orthodox Presbyterian tradition. According to the late Greg Bahnsen (1976a, 1976b) its leading contemporary advocate, the basis of TAG can be found in the Apostle Paul but the argument has its modern roots in the writings of Bahnsen’s mentor, Cornelius VanTil (1955, 1969a, 1969b). TAG has also been used recently by Douglas Jones in exchanges with Keith Parson and also with me. (Jones, 1991, Parsons, 1991, Martin, 1991a). Bahnsen relied almost exclusively on variations of TAG in his debate with the atheist Gordon Stein at University of California, Irving in 1985 (Bahnsen-Stein) and in a radio debate on the radio station KKLA with the atheist George Smith (Bahnsen-Smith). By Bahnsen’s own admission he planned to rely on TAG in a debate with me that was scheduled at Rhodes College in Memphis, Tennessee in October, 1994 but did not take place (Bahnsen, audiocassette #2.) because I refused to allow the debate to be taped and sold to support a Christian organization. Bahnsen died in 1995. Recently, I published a paper (Martin, 1996) arguing the reverse of TAG, that is, that logic, science, and ethics presupposes the nonexistence of God. I called this argument The Transcendental Argument for the NonExistence of God (TANG). This paper was reprinted on the Secular Web on the Internet and stimulated a debate found on the Internet between John Frame, an advocate of TAG and me, and generated an exchange between Michael Butler, a follower of Bahnsen, and me. Whether TAG will become better known remains to be seen, but in any case a refutation is needed if for no other reason than to arm nonbelievers for possible encounters with its advocates.

An Overview of TAG

The basic idea of TAG when used against atheists is easy to understand and state. Its maintains that certain things that atheists assume are true can only be true if there is a God. Primarily these atheistic assumptions are the beliefs that logical reasoning is possible, that scientific inference is justified, and that objective moral standards exist. So if an atheist uses logic to refute a theistic argument, uses scientific evidence to undermine some biblical position, or argues that God’s omnipotence and moral perfection are incompatible with evil in the world and consequently that God does not exist, TAG maintains that he or she is implicitly assuming God’s existence. Logic and science would be impossible without God, TAG’s advocates say, and the argument from evil assumes an objective standard of evil which is also impossible without God.

The way TAG has in fact been employed by VanTil, Bahnsen, Jones and Frame is more specific in its intent than I have indicated, however, for these thinkers want to establish not theism per se but Christian theism. Accordingly they argue that logic, scientific inference, and objective ethics presuppose the Christian world view. Indeed, according to them, everything from Hinduism to Taoism, from Islam to Buddhism is refuted by TAG. Since these positions all rely on logic, science and objective moral standards, they all presuppose Christianity.

Christians who use TAG acknowledge that they constitute a small minority in the Christian world. Their minority status becomes clear in terms of the types of Christianity they reject. VanTil rejected Roman Catholicism, liberal Protestantism, and indeed any form of Christianity that assumes that human knowledge and reason are independent of God’s revealed authority (Van Til, 1955, chapter 7). Bahnsen followed VanTil on this point. In a historical survey of Christian apologetics he argued that with very few exceptions Christian thinkers have wrongly assumed the Socratic position that human knowledge and reason can be independent of God (1976a). Indeed, at times Bahnsen seemed to imply that VanTil was the first Christian thinker since the Apostle Paul to see clearly that human knowledge and reason are utterly dependent on the Christian God (1976a, p. 232). Whether Bahnsen was correct or incorrect in his assessment of VanTil, his assessment clearly indicated that he believed that the number of advocates of TAG Christianity was relatively small.

The Invalidity of the TAG as a Proof of Christianity

If Bahnsen is correct that logic, science and objective moral reasoning presuppose the TAG Christian worldview, does this show that the Christian worldview–let alone the TAG Christian worldview–is true? No, it does not.

To put what Bahnsen meant by “presuppose” in terms often used by him: To say that A presupposes B is to say that we could not “make sense” of A without assuming B. However, supposing we grant that one must assume B to make sense of A, it does not follow that B is true. For example, if I am trying to communicate to an audience by speaking to them in English, my action makes no sense unless they understand English. But it does not follow that they do. They might only understand Chinese. Scientists listening to radio signals from outer space in order to make contact with extraterrestrial life presuppose that such life is possible. But it does not follow that it is. Similarly, if, as Bahnsen claimed, the Christian worldview is presupposed by science, logic, and objective ethics, it does not follow that the Christian worldview is true. It might be the case that science, logic, and ethics are impossible and should be rejected. TAG would not establish the truth of the Christian worldview but only the inconsistency of atheists who presuppose. science, logic and objective ethics.

Furthermore, it is clear that TAG assumes particular interpretations of science, logic, and ethics. For example, Bahnsen assumed an inductive interpretation of science, a metaphysical view of logic, and an objective construction of ethics such that any denial of objectivity would be moral anarchy. However, other interpretations of science, logic, and ethics are possible. So even if TAG is valid, science, logic, and ethics conceived in other ways are not ruled out. In particular, science can be conceived in non-inductive ways, for instance as the putting forth of bold speculative theories and the refutation of them by rigorous empirical tests (Popper, 1959). Logic conceived in metaphysical terms may indeed be problematic and be better thought of in different terms. Perhaps, for example, the principles of logic should be considered as instruments. However, so construed they need not be arbitrary since they are adopted for certain purposes (Nagel, 1964). Objective ethics might be impossible, but this does not mean that ethics conceived in others ways is impossible. Moreover, a subjective based ethics need not entail moral anarchy or nihilism for human beings can have good prudential reasons to create moral systems with prohibitions against murder, stealing, and so on (Mackie, 1977).

In short, TAG , even if valid, does not demonstrate the truth of Christianity — let alone TAG Christianity. But is it valid? Do logic, science and objective moral reasoning presuppose the Christian worldview?

Induction and TAG: A Test Case

There is, however, a problem that stands in the way of any clear direct evaluation of its validity. In order to evaluate TAG systematically it is necessary to have a clear statement of it. I have been unable to find one . To be sure, the conclusion of TAG is clear enough. However, although Bahnsen in his lectures reiterated TAG’s conclusion, he said very little about how this was reached.

One part of TAG is that inductive inference–that is probabilistic inference in which the conclusion is supported but not necessitated by the premises–presumes the existence of the Christian God. This is the part I will consider in the present article. The inductive inference part of TAG is an appropriate place to begin a critique of TAG for this is what Bahnsen talked most about in his lectures. Although limitations of space prevent me from considering the logic and ethic aspects of TAG here, these aspects were discussed at some length in my debate with Frame on the Secular Web.

Inductive Skepticism and TAG

Bahnsen argued that with the assumption of a Christian God, induction has a solid foundation. Without the assumption of the Christian God, he said that we would be reduced to inductive skepticism, the view that there is no good reason to use inductive inference and to believe that induction has a rational basis. Since he assumed that all of science is based on induction, he therefore maintained that science itself presupposes the Christian God, and that, without God, science has no rational foundation. Thus, Bahnsen accused atheists who use science in arguing against Christianity of presupposing the truth of the very thing they were attempting to refute.

Skepticism about Inductive Skepticism

Christian apologists like Bahnsen who appeal to TAG acknowledge their debt to David Hume, the eighteenth century Scottish skeptic, and Bertrand Russell, one of the twentieth century’s most famous philosophers. Both thinkers raised skeptical questions about induction. Bahnsen’s strategy was to take these seriously and then try to show that belief in the Christian God could dispel them. Unfortunately, he exhibited no awareness of the philosophical arguments that have challenged inductive skepticism in general and Hume’s and Russell’s versions of it in particular.

In contemporary thought a valid deductive argument is an argument in which the conclusion is necessitated by the premises. For example, the conclusion “Fido has four legs” is necessitated by the premises ” All dogs have four legs” and “Fido is a dog” Thus it is one in which the premises cannot be true and the conclusion false. A strong inductive argument, on the other hand, is an argument in which the premises make the conclusion very probable but do not necessitate it. Thus, inductive arguments are probabilistic, hence not deductive, arguments. For example, the conclusion ” Mr. Lee has brown eyes” is very probable relative to the premises ” Almost all Chinese have brown eyes” and “Mr. Lee is Chinese. ” It is one in which the premise can be true and the conclusion false.

Inductive skeptics maintain that there are no strong inductive arguments, but they go further than this for they also maintain that no inductive argument is any stronger than any other. Consequently, they say that there is no reason on the basis of any evidence to prefer any hypothesis over its negation. For example, an inductive skeptic would maintain that it is no more probable that the sun will come up tomorrow on the basis of past evidence than that it will not. This inductive skepticism is sometimes affirmed by saying either that induction is not justified or that it is not rational to use induction. Of course, the inductive skeptic would admit that if we could made certain assumptions about the world–for example, the assumption that nature is uniform–induction would be justified and it would be rational to use it.. But these assumptions cannot be made without justification. And, according to the skeptics, no justification of them is possible without assuming induction.

On the standard interpretation of Hume that Bahnsen accepted, Hume is supposed to have shown that probabilistic arguments — what I characterized above as inductive arguments– are unjustified. However, it is open to question that Hume held this modern view. A detailed analysis of Hume’s works has shown that by “probabilistic argument” Hume meant a certain type of deductive argument (Stove, 1966). Hume believed that all such arguments presuppose the uniformity of nature, but he did not attempt to show that probabilistic arguments in the modern sense are unjustified. Thus, appeals to Hume prove very little about whether inductive, that is, probabilistic arguments, are justified.

Even if Hume was talking about what is now called induction, other philosophers have argued that the traditional problem of induction — why it is rational to use induction– is a pseudo-problem that should be dissolved, not solved. Some philosophers have maintained that the traditional problem of induction is based on a linguistic confusion (Strawson, 1966, Edwards, 1965). If we carefully consider what we mean by “rational”, we will see that denying the rationality of induction is nonsense. More recently, it has been argued that by using unproblematic principles of probability inductive skepticism can be reduced to absurdity (Gemes, 1983). In other words, according to this argument, the position of inductive skepticism cannot be coherently formulated. If valid, these arguments show that inductive skepticism is a view that does not deserve to be taken seriously. Bahnsen does not answer these general arguments against inductive skepticism. Indeed, he does not seem to be aware of them. Moreover, Russell’s skepticism about inductive arguments has also taken some heavy pounding. Philosophers have pointed out confusions in the very passages from Russell’s writing that Bahnsen cited with approval (Wills, 1965; Edwards, 1965).

Even some philosophers who accept the view that Hume has shown that inductive arguments are unjustified would challenge the view endorsed by Bahnsen that science presupposes the justification of induction. They would argue that the practice of basing one’s action on inductive arguments can be pragmatically vindicated: if there are any true inductive generalizations, the consistent use of induction will discover them in the long run (Reichenbach, 1996). Although this approach does not justify induction it provides a practical reason for continuing to use this mode of reasoning. Other philosophers maintain that the demand to justify induction can be attenuated by showing that it is pointless, and they argue that a trivial justification for inductive action can be given: one uses induction because it makes getting through life easier and, although we don’t know whether induction will continue to have this effect, the only way to discover if it will is to continue to use it (Madden, 1960).

Whether these or other approaches to inductive skepticism are viable is an open question that is still debated in the philosophical literature. Until this controversy is settled, both Bahnsen’s view that induction is open to challenge and his assumption that science is impossible without induction remain in doubt.

The Prima Facie Failure of the “Make Sense” Test

Putting aside the fact that the truth of inductive skepticism and its relevance to science is far more debatable than Bahnsen assumes, the position that induction presupposes the Christian God is implausible in its own right. Recall that Bahnsen maintains that to say that A presupposes B is to say that we could not “make sense”of A without assuming B. Now consider what it would mean to say that being a sister presupposes being female. One could not make sense of someone being a sister unless one presupposed this someone was female. Using this test, being a sister does indeed presuppose being a female. But contrast this case with the claim that being rational presupposes being human. This later seems to fail the test for in order to make sense of someone being rational, it is not necessary to suppose that this someone is human. Indeed, many science fiction stories that assume the rationality of alien life forms make perfectly good sense.

What about the claim that induction presupposes the Christian God? There is nothing nonsensical in supposing that inductive inference is justified and that Christianity is false. We do not need to assume Christianity to make sense of induction. Indeed, that no such assumption is necessary would be the position of most Christians. So Bahnsen’s claim fails the “make sense” test and must be rejected. Of course, it is possible that there are subtle arguments that prove the truth of Bahnsen’s claim. Whether there are remains to be seen.

Does the Christian World View Answer Inductive Skeptics?

I have argued so far that inductive skepticism has been questioned in many different ways that are independent of Christianity. Now let us consider whether Christianity provides a justification of induction and answers the inductive skeptic.

One argument suggests that humans could never be assured of the uniformity of nature on the Christian worldview. According to Bahnsen and other Christian apologists, it is possible that God has morally sufficient reasons for allowing evil in the world although we do not know what these are. For example, God could have a morally sufficient reason for allowing the Lisbon earthquake that killed thousands of innocent people although we don’t know what it was.

Now suppose certain uniformities of nature will fail to hold in the future. Suppose after the year 1998 all emeralds will be blue and all rubies will be green. If God could have a morally sufficient reason for the Lisbon earthquake, surely He could have a sufficient reason for causing such a departure. Indeed, just as, according to Christians, all evil in the world can be accounted for by saying that God had a morally sufficient reason for causing it or permitting it, so any departure from the uniformity of nature could be accounted for by postulating that God has an unknown reason for causing these departures. To be sure, we know of no such departures by God in the past but this is no reason to suppose that He will not make them in the future: that God has not had a sufficient reason to depart from the uniformity of nature until now does not mean that He will not have one in the future. God would not be deceiving us since He never assured us that all our expectations about the future would turn out to be true.

Noah and Continuing the Seasons

What would Bahnsen’s answer be to this criticism? He sometimes appealed to passages in Scripture to justify belief in the uniformity of nature; for example, he cited the passage in Gen. 8. 20-22 that God said to Noah that He would continue the seasons (Bahnsen, audiocassette #1). There are, however, at least four basic problems with scriptural appeals. First, there is the question of why we should believe these passages. Why suppose that Noah existed? And supposing he did exist, why think that he made a covenant with God to continue the seasons? Second, there is the question of why we should interpret this passage to mean that nature will be uniform in the usual sense. After all, the seasons can be continued with huge changes in the uniformity of nature. In winter snow could be green, in spring flowers could have no smell, in summer grass could be pink, and so on. God did not say in detail how he would continue the seasons. Third, God’s promise is compatible with inductive chaos in most of the universe. God said “that while the earth remains, seed time and harvest, cold and heat, summer and winter, day and night, shall not cease” (Gen. 8. 22) and this passage is compatible with a state of affairs in which the present of laws of nature do not hold outside of the Earth and its environs. Fourth, why suppose that God would necessarily keep his covenant with Noah? God can break a promise so long as He has morally sufficient reason to do. If we do not blame human beings for breaking covenants if they have good reasons, why should we blame God? Moreover, God might not be responsible for the failure of the uniformity of nature. Satan could have decided to work his evil ways by bringing inductive chaos into the world and God could not interfere without depriving Satan of his free will.

Learning Sans Induction

Another reason that Bahnsen gave for his belief that the problem of induction is solved by accepting the Christian worldview is that without the uniformity of nature, human beings could not learn; however, God wants us to learn (Bahnsen, audiocassette #3). But is the uniformity of nature–the assumption that all present known lawful regularities will hold throughout time and space–necessary for human learning? Bahnsen’s reasons here are just as problematic as they are in the case of God’s covenant with Noah. First of all, on the Christian worldview God is all powerful. But then, there would be ways for humans to learn other than via induction based on the uniformity of nature. For example, God could give humans innate knowledge of the future. Alternatively, God could give us super powers of precognition or He could directly reveal to us what the future would be.

Moreover, the absence of the uniformity of nature is compatible with learning from induction so long as there is local uniformity on Earth and its environs. Inductive chaos might reign in the universe, but so long as uniformities continued on Earth, humans could learn from experience. In addition, learning from induction is compatible even with local failure of the present laws so long as this is not complete. Suppose, for example, that after 1998 only statistical laws held on the macro level so that for instance fire is hot only 98% of the time. This would be sufficient to teach us not to get burned. Indeed, complete failure even on the macro level would be compatible with learning from experience so long as it did not happen too often and was not too disruptive. Thus, for example, after 1998 rubies might change color randomly and dogs might sometimes turn into cats although all other uniformities would persist. Clearly, in this case we could learn from experience even though the uniformity of nature as it is normally understood no longer existed.


The inductive part of TAG fails. I have not shown that new arguments developed by followers of Bahnsen for the inductive part might be more successful than the ones I have evaluated. However, this prospect seems unlikely given the weakness of the arguments used by Bahnsen over many years. Although I have not shown here that the logical, and ethical parts of TAG are equally unsound, arguments given in my debate with Frame and my exchange with Butler suggests that they are. Lastly the failure of any aspect of TAG does not show that God does not exist. What a failure of TAG does show is that it cannot be used to accuse atheists of inconsistency, let alone be used to support belief in the existence of the Christian God.


Bahnsen, Greg L . audiocassette #1. “How to Argue With Atheists?” Edmonton, Canada: Still Water Revival Books.

________. 1976a. “Socrates or Christ: The Reformation of Christian Apologetics.” In Foundations of Christian Scholarship, North, G. ed. Vallicito, Calif.: Ross House Books, pp. 190-239.

________. 1976b. “Pragmatism, Prejudice, and Presuppositionalism.” In Foundations of Christian Scholarship, North, G. ed. Vallicito, Calif.: Ross House Books, pp. 240-92.

________ . audiocassette #2. “The Debate That Never Was. ” Nash, TX: The Covenant Tape Ministry.

_________ . audiocassette #3. “Proof for God’s Existence.” Nash, TX: The Covenant Tape Ministry.

Bahnsen-Smith. “A Case For/Against God” (Debate). Nash: TX: Covenant Tape Ministry, audiocassette.

Bahnsen-Stein. ” Does God Exist?”(Debate) Edmonton, Canada: Still Water Revival Books, audiocassette.

Edwards, P. 1965. “Bertrand Russell’s Doubts about Induction. ” In Flew, A. ed., Logic and Language, First and Second Series. Garden City, N.Y.: Doubleday, pp. 59 -85.

Gemes, K. 1983. “A Refutation of Inductive Skepticism,” Australasian Journal of Philosophy, 61, pp. 434 -38.

Jones, Doug. 1991. “The Futility of Non-Christian Thought,” Antithesis, Vol. II, July/August, pp. 40-2.

Mackie, J. L. 1977. Ethics: Inventing Right and Wrong. NY: Penguin Books, 1977).

Madden, E. H. 1960. “The Riddle of Induction. ” In The Structure of Scientific Thought, Madden, E. H. ed. Boston, MA: Houghton Mifflin, pp. 318-20.

Martin, Michael, 1996. “The Transcendental Argument for the NonExistence of God,” The New Zealand Rationalist and Humanist, Autumn, 1996, p. 4.

____________. 1990. Atheism: A Philosophical Justification. Philadelphia: Temple University Press.

___________. 1991a. “Is A Non-Christian Worldview Futile?Antithesis, Vol. II, July/August, pp. 44-6.

____________. 1991b. The Case Against Christianity. Philadelphia, PA: Temple University Press.

Nagel, Ernest. 1964. “Logic Without Ontology. ” In Benacerraf, P. and Putnam. H. ed. Philosophy of Mathematics. Englewood Cliffs, N.J.: Prentice Hall, Inc. , pp. 302 -321.

Parson, Keith. 1991. “Is Non-Christian Thought Futile?Antithesis, Vol. II, July/August, pp. 42-4.

Popper, Karl. 1959. The Logic of Scientific Discovery. NY: Basic Books, Inc.

Reichenbach, Hans. 1966. “The Justification of Induction.” In Foster, M. and Martin. M. (ed.), Probability, Confirmation and Simplicity, pp. 423-34.

Stove, David 1966. “Hume, Probability and Induction.” In Hume, Chapel, V. C. ed. Garden City, N.Y.: Doubled, , pp. 187-213.

Strawson, Peter F. 1996. “The ‘Justification’ of Induction.” In Foster. M and Martin. M,. ed., Probability, Confirmation, and Simplicity, New York: The Odyssey Press, pp. 440-49.

Van Til, Cornelius. 1955. The Defense of the Faith Philadelphia, PA.: The Presbyterian and Reformed Publishing Co.

_____________. 1969a. A Survey of Christian Epistemology. Ripon, CA.: den Dulk Christian Foundation.

_____________. 1969b. A Christian Theory of Knowledge, Nutley, NJ.: The Presbyterian and Reformed Publishing Co.

Wills, Frederick. 1965. “Will the Future be like Past?” In Flew, A. ed., Logic and Language, First and Second Series. Garden City, N.Y.: Doubleday, pp. 248-267.

“Does Induction Presume The Existence Of The Christian God?” is copyright © 1997 by Skeptic magazine. All rights reserved. Electronically published by Internet Infidels on the Secular Web with the written permission of Skeptic.

Skeptic magazine is the quarterly voice of the Skeptics Society, founded in 1992, that has a 4-color cover and runs about 112 pages per issue. Each issue features a special section on a particular theme with several articles pro and con (e.g., False Memory Syndrome v. Repressed Memory Syndrome, the AIDS Skeptics, Holocaust Revisionism, Race and IQ, Cosmology and God, Conspiracy Theories), plus an array of news items, forum letters (more than any other magazine we know of) discussing all manner of subjects demanding skepticism, long and short book reviews (e.g., The Bell Curve), an interview with an influential scientist (e.g., Richard Dawkins, Stephen Jay Gould, Charles Murray, Martin Gardner, Frank Sulloway), and much more.

If you want to subscribe to Skeptic magazine you can do so on the Internet Special for $25.00 (student rate $20.00) instead of the normal $35.00. (Foreign country rates are $45.00 instead of the normal $55.00.) Just e-mail your Visa or Mastercard Number, the expiration date, name, address, phone, and your subscription request, and we will do the rest. (You can also fax, call, or mail the number in as well.) The Special includes an Automatic Subscription Renewal each year so you do not have to bother renewing (just like Internet carriers automatically bill customers with their credit card numbers–the wave of the future for all magazines–and, of course, you can cancel any time).

If you want to just subcribe normally, you can write us at P.O. Box 338, Altadena, CA 91001; phone: 818/794-3119; Fax: 818/794-1301; e-mail: skepticmag

Skeptic has a WWW page at http://www.skeptic.com/

and an FTP site at: http://www.skeptic.com/

all rights reserved