Science in Christian Perspective

Science, Scientism and Christianity: 
The Ideas of D.M. MacKay

Physics Department
Oglethorpe University
Atlanta, Georgia 30319

From: JASA 37 (September 1985): 142-148

Those who reject neither science nor Christianity are forced to undertake three tasks to distinguish science from scientism and from Christianity and to show compatibility between science and Christianity. The work of D.M. MacKay is examined as an example of the carrying out of these tasks. Particular attention is given to complementarity and the idea of levels of explanation.

The tremendous impact of science on modern thought has created subtle but serious problems for Christian thinkers. The tension between scientific attitudes and conclusions on one hand and Christian faith and beliefs on the other has propelled Christians into a spectrum of reactions toward science. These reactions have ranged from outright rejection to uncritical acceptance of science. A less extreme and certainly popular strategy for alleviating the tension is based on the claim that science is distinct from scientism (or "false science"). The tension is then regarded as originating with the scientism and the proponent of this view proceeds to accept science but reject scientism. Not surprisingly, the definition of "scientism" varies, but generally it refers to improper extensions of science.

This strategy can obviously be quite successful at reducing the tension between science and Christianity. The success, however, hinges on whether or not several key propositions can be plausibly defended. The first proposition is that science is not the same as scientism; there is a real distinction to be made between them. Secondly, science neither logically nor even probably entails scientism because, if science and scientism go together like a horse and carriage, "you can't have one without the other.

If these first two propositions can be established, one still must show that science and Christianity are compatible though distinct. Thus there are three propositions to be established in carrying out what we might call the compatibilist strategy. First, science must be distinguished from scientism. Then, the distinction must be shown to be profound enough to allow separation of the two. Finally, science should be shown to be compatible with Christianity.

Once the strategy is outlined, it is not difficult to see that many thinkers employ variations on this basic theme as they seek to defend and advance Christian ideas. Of course, the terminology is variable. Some writers never use the word "scientism," preferring instead more pejorative terms, such as "science falsely so-called." Also, the definitions of "science," "scientism" and "Christianity" vary. Nevertheless, however terms are defined, once the basic decision to accept both science and Christianity has been made, it is almost inevitable that this strategy will be followed. Anyone who deviates from the pattern must be regarded as highly original.

MacKay's Strategy as a Compatibilist Strategy

A good strategy must be supported by good tactics if any effort is to succeed. In order to see the compatibilist strategy in operation and as an opportunity to judge the effectiveness of some of the tactics that have been used, I would like to examine a particular example, choice of the ideas of Donald M. MacKay1 as an example is not random. MacKay's ideas have had considerable influence both in England and, more recently, in the United States. Hence, he must be considered an important (though perhaps not an inten
tional) practitioner of this strategy.

MacKay supports the first proposition, that science is distinct from scientism, by defining science and scientism in such a way that it is obvious they are different. He characterizes science as an approach to understanding the universe in which one assumes the existence of an ordered universe and then proceeds to test postulated orderings of that universe against experience. Owing to the inherent limitations of empirical procedures, science is tentative in the sense that no claims of absolute certainty can be made for its conclusions. Additionally, MacKay attaches considerable importance to observational detachment as a feature of scientific methodology.

Scientism is not a common word in MacKay's writings but I think we can fairly generalize from his remarks with respect to specific forms of scientism, e.g., Evolutionism.2 Evidently, for MacKay, scientisms would be extensions of the methods (and, perhaps, theories) of science into a metaphysical modus operandi of the universe. Scientisms then use the explanations of science to debunk religious explanations.

If this interpretation is correct, MacKay distinguishes science from scientisms primarily in terms of correct and incorrect use of methods. In science, the methods used are consistent with the goals, substance, and conclusions of the discipline while in scientism those same methods are used outside their range of proper applicability.

When it comes to the second proposition, that scientism does not necessarily flow from science, MacKay's
efforts are confined primarily to one area in which he,  as a brain physiologist, has special interest. He is quite
 properly concerned with the implications of a form of The scientism he calls "machine-mindedness." As he
defines the position, "machine-mindedness" is the dual  conviction that man's mind is causally determined and
 man's decisions are, therefore, governed by "moral determinism." In order to show there is no logical
connection between causal determinism and "machine-mindedness, he uses an interesting example3 in
which be allows for the sake of argument that causal determinism is true of the mind.

 MacKay's discussion of the example hinges on the distinction between the terms "inevitable" and "inevitable for you." Suppose, he suggests, some clever person were able to precisely ascertain your brain state so that  correct predictions of your decision following any brain state became possible. MacKay admits this clever observer would then be correct to regard your decisions  as inevitable and, hence, determined. However, MacKay insists that the decision is still not inevitable for you and the future is not inevitable for you. The reason is that your brain state in belief is different from your brain state in unbelief. For a particular predicted  brain state to be inevitable for you, you must consider and accept the prediction as true (inevitable) and that
must after the brain state on which the prediction is based. If the observer adjusts for that and bases his
 prediction on the state of your brain when you believe, then by not believing you nullify the prediction by not
 being in the state on which the prediction was based.

MacKay's point is that the causal determinism noted  by the clever observer does not imply that your decision is logically determined. Consequently, moral decisions  are free in some sense and moral determinism does not  follow from causal determinism. In my terms, the  science (used by the observer) does not entail the  scientism, (moral determinism).

John A. Cramer is a physicist by training, with degrees in physics from Wheaton College (B.S.), Ohio University (M.S.) and Texas A & M University (A.D.). His areas of specialization have been low temperature solid state physics and the kinetic theory of gases. Dr. Cramer has taught at Wheaton College and The King's College, and is currently Associate Professor of Physics at Oglethorpe University in Atlanta, Georgia.

MacKay's argument has received mixed response."4,5 C. Stephen Evans comments, "This is a puzzling argument and it is difficult to know what to make of it."6 For me, the most puzzling feature of the argument is how discussion turns from a causally determined situation into one where the subject suddenly has a choice. It seems that the term "inevitable for you" is a magic wand! When the subject examines the cleverly adjusted prediction which will be true only if he believes it to be true, why does MacKay think the subject can choose not to believe? The obvious answer is that we all know he has a choice. That, of course, begs the question.

MacKay never actually says the subject can choose to not-believe. He says the subject would not be wrong to not-believe. If he really means the subject would not be wrong to not believe but still cannot choose to not believe, I think he should say so explicitly to make clear what sort of moral indeterminism he is offering us. Of course, then it is hard to understand how he can say the future is not determined for you.

Taking MacKay's side, I think the reply is that logical indeterminacy is the issue here. Perhaps he would say that the introduction of a conscious agent into the situation renders the logically possible also physically possible.

A thorough causal determinism, as assumed at the start of the example, permits no such response. Conscious agents are causally determined with perhaps illusory options but certainly no real options. Logical truth tables of what is true or false if this or that happens can never tell us just what will happen.

MacKay can still salvage the argument if he equates logical inevitability with moral determinism. Then the existence of two logical possibilities does indeed imply moral indeterminism. Perhaps he does mean this but then it is bard to see why an involved discussion is necessary to establish the point. However, if this is what he means, then the subject would not be wrong to Dot-believe the prediction but neither would he be able to not-believe it. If this is freedom, it isn't worth much.

Strategically then, at best, MacKay has driven a wedge between science and one form of scientism. Showing that science does not logically entail scientism is vital but it is desirable to use as many wedges as possible in order to secure the split. Differences in method or epistemology or esthetic sense should be demonstrated if and where possible.

It is to the third proposition, that science and Christianity are compatible though distinct, that MacKay gives most attention. He shows science is distinct from Christianity in at least five ways.7 Firstly, he suggests science does not deal with or usually ignores certain important questions. Questions of the significance of the universe or of human existence lie outside the self-imposed limitations of science. Secondly, he holds that science is ". . . not an alternative to God as a source of truth, but a specialized way of gathering and discovering patterns in data. . . . "8 Thirdly, he views theological statements as not readily testable against experience. Fourthly, he notes that detachment, which he insists is necessary for science, is neither appropriate nor possible in Christianity. Finally, be argues that science provides no information on man's spiritual needs of forgiveness from sin and of healing the broken relationship with God.

The compatibility of science and Christianity is a major theme of MacKay's work. Briefly, he argues for compatibility by insisting that science and Christianity "I . . are not rivals but are complementary, each appropriate to an area of experience largely ignored by the other."9 In fact, both views are necessary; ".  there is not only room for but need for stories of both kinds to be true at the same time. What we have to ask is ... which story is relevant to a particular context."10 However, ". . . the religious account of reality is logically 'higher' than the scientific: it presupposes that some scientific description can be given of the world of

Showing that science does not logically entail scientism is vital but it is desirable to use as many wedges as possible in order to secure the split.

created events, and goes beyond it by claiming to reveal the significance of those events. In this sense ... the biblical-theistic account of reality embraces the scientific."11

MacKay safeguards this complementary relationship by attacking "nothing-buttery" which is the conviction that once science has explained a phenomenon, no further explanation is needed or possible. His attack takes the form of a number of examples which, he is convinced, show that an explanation in one set of terms does not necessarily debunk an explanation in another set of terms. Specifically, he regards these examples as counter-examples to "nothing-buttery"12

I think it is clear from the previous outline that MacKay's ideas can be fitted into the pattern of the strategy I have described. Although I regard the strategy as fundamentally sound, I have a caveat. Generally, the approach suffers from excessive confidence in the making of distinctions. It is, after all, an assumption that the scientific world-view is constructed of two separable parts, one good (science) and the other bad (scientism). Certainly there are those who contend the parts are not only inseparable but naturally (even logically) connected. When the Christian thinker has made his distinctions and distilled the impure mixture down to a residue of pure science, what guarantees the residue will be all good? Might not "pure science" need purifying?

The Tactical Use of Levels of Explanation

Turning from strategy to tactics, I want to focus especially on the arguments and concepts MacKay employs to show science and Christianity are compatible. Key concepts here are "levels of explanation" and "complementarity. " We will examine these in the next two sections. Additionally important is the conclusion that an explanation at one level does not invalidate an explanation at another level.

Because of its importance in the discussion, let us define "explanation" as a set of statements about a set of phenomena and their interrelationships. This is obviously a very minimal definition which overlooks many important features of an explanation. The quality of an explanation is surely important, as is internal consistency but such details need not detain us. When any statement of one explanation contradicts any statement of another explanation, I will call the two explanations "contradictory explanations."

As an illustration of the idea of levels of explanation, MacKay calls attention to a sign reading "EXIT" where the letters are cut from newsprint.13 Focusing first on the microscopic dots of ink comprising part of a letter "e" in a word on the newsprint, we see only a random set of dots. If we lower the magnification or back away, the letter "e" itself is visible. At even lower magnification, the word of which the letter is a part, perhaps " set," appears. At a greater distance we recognize the newsprint. From a yet greater distance, the word " EXIT" is discerned. An account of what we see at any of these stages is an explanation of what is seen at that stage. MacKay says these various explanations of different stages are different levels of explanation of the ink dots. At the lowest level (highest magnification) we might explain them as random dots, At the highest level we would consider them to the extent they help to convey the message "there is an exit over here."

Note that each level explains different data. For example, the dots against a white background are the subject of the first (lowest) level while the whole sign and its message is the subject of the highest level. In this example, the subject of any level is part of the subject of any higher level. For example, the random dots are still accounted for at the level where the letter "e" is recognized but here they can be seen to fit into a larger context. In other words, the subject of any level is a subset of the subject of any higher level of explanation. Levels related in this manner I call "nested levels" of explanation.

Explanations might be related in other ways. Subject sets might overlap, having an area in common. With a large degree of overlap, it might make sense to refer to explanations of these subject sets as different levels of explanation and I will call them "overlapping levels" of explanation.

An extreme form of both overlapping and nested levels is the case where the subject sets are the same. I will call different explanations of the same subject "homologous" levels. A higher level of two homologous levels would be the more complex of the two.

. . The subject of any level is a subset of the subject of any higher level of  explanation.

Two nested levels of explanation will not necessarily invalidate each other. An explanation of the ink dots as part of the letter "e" certainly is compatible with the view of the dots one might take at the level where the newsprint was under consideration. However, it is possible that an explanation at one level could invalidate another level of explanation. An explanation of the ink dots along the lines that their configurations were carefully chosen by an abstract artist must be regarded as false once we have recognized the dots as parts of a piece of newsprint.

Can a lower level of nested levels ever invalidate higher nested levels? Since a higher level is constructed from more information about the context of the data of the lower level, we ordinarily do not encounter examples of this sort, For example, if we say science is a lower level explanation of the universe and Christian Science (as formulated by Mrs. Eddy) is a higher level explanation (by virtue of its scope), can we say that science invalidates Christian Science? The two are surely contradictory and incompatible but what criteria do we use to show that one invalidates the other? The criteria for higher and lower levels are of no use here. Certainly we will not say that Christian Science invalidates science because it is a higher level explanation, Thus, conflicts between nested levels are not resolvable without reference to criteria beyond those that distinguish higher from lower.

In the same way, overlapping levels of explanation may or may not invalidate each other. Likewise, determining which of two levels is higher has no bearing on the question of which one is invalidated if and when explanations at different levels disagree.

As an example of invalidation in overlapping levels of explanation, consider: a) all the paintings of Picasso, and, b) all abstract paintings. Some but not all Picasso I s paintings are abstract and some but not all abstract paintings are Picasso's. Now suppose an art critic finds a convincing way to argue that all Picasso's work was motivated by financial considerations alone. This explanation surely contradicts an attempt to explain all abstract painting as an exploration of territory newly opened up to artists by changing ideas of space, time and motion. Of course, a synthesis may be possible but the point is that not all overlapping levels of explanation are mutually compatible.

We then conclude of nested and overlapping levels of explanation that each situation must be considered separately. If two levels contradict, there is no a priori certainty of how the situation will be resolved. A higher level does not necessarily have preference, so questions of what constitutes a good or complete explanation must arise.

Questions of higher and lower are obviously irrelevant for identical levels of explanation where the subjects are the same. Again, questions of what a good explanation is must arise. Another criterion appropriate to homologous levels which cannot be applied for debunking purposes to other types of levels (although it can be used to show the need of another level) is Occam's razor. According to this rule, we decide which explanation is preferred on the basis of not proliferating assumptions and concepts beyond what is necessary. The best explanation has no more and no fewer than the requisite number of concepts. The rule should not be used until considerations of goodness and completeness have been weighed.

We have found, then that the claim that two explanations are explanations at different levels tells us nothing about which is to be preferred. Claims about different levels must be handled on a case by case basis. If two explanations are contradictory we still do not know which is preferred because contradiction is a symmetrical relationship. However, it is obviously impossible f or both of two contradictory levels to be accepted in unaltered form.

Evidently MacKay views the explanations of science and Christianity as nested levels. He tells us that "the biblical-theistic account of reality embraces the scientific."11 The Christian explanation encompasses the significance of phenomena while the scientific explanation virtually ignores such concerns. As to contradiction, MacKay clearly does not expect science and Christianity (as properly formulated?) to contradict each other. The non-contradiction is insured by complementarity, on which I will have more to say shortly.

To this point in the discussion of tactics, I feel relatively comfortable with what MacKay is doing. When he turns the concept of levels of explanation into an attack on "nothing-buttery," problems appear.

The problems center on the word "debunk." When

We are forced to conclude that MacKay's tactics against " nothing-buttery" are largely unsuccessful.

does one explanation debunk another? MacKay appears to mean "debunk" in the sense "contradict" when he says, "it is only where we can demonstrate that the truth of a theistic claim would logically rule out the truth of a scientific one, or vice versa, that we have a right and duty to see them as opposites."14 However, when he explicitly sets out to answer the question of the meaning of "debunk" he says one explanation debunks another when One story ". . . would have had to be different if the other story had been different. "15 This is a test of relatedness but it gives us no criteria for deciding which story should be judged to be debunked.

This vague treatment Of the word "debunk" is no virtue in light of the important role it plays in the attack on "nothing-buttery." His argument against "nothingbuttery" is essentially the remark, buttressed by examples," that an explanation in one set of terms does not necessarily debunk an explanation in another set of terms. The remark is true but irrelevant because, as we have seen, regardless of which sense of "levels of explanation" is in use, the question of contradiction between levels must be handled case by case. Likewise, the examples are irrelevant when case by case handling is needed.

Unfortunately, MacKay makes no attempt to show that "nothing-buttery" in actual fact does not debunk Christianity; he only suggests it might not (does not necessarily). Apparently he does not appreciate the case by case nature of the situation. Even for one who believes the argument and examples have weight, this omission is astonishing. He should press on. His conclusion as it stands is obviously too weak for satisfaction. We want to know if Christianity stands. MacKay tells us, "maybe," a less than reassuring response.

A final difficulty with the discussion of "nothingbutterv" is more subtle. I am uncertain of how MacKay would categorize " noth ing- buttery" but it seems, to me, that " nothing- buttery" is a scientism which (as scientisms typically do) purports to have an explanation for everything. It is, of course, a severely truncated world-view; positivistic world-views always are truncated. If I am right, then Christianity and "nothingbuttery" stand to each other as homologous levels of explanation for they claim to explain everything to some extent. Occam's razor then properly enters the picture here and "nothing-buttery," on the face of it, seems to be the winner. The only tactic that appears to offer hope would be an attack on the adequacy of the explanations presented by "nothing-buttery."

Apparently, MacKay views his examples as just that sort of attack because he insists they are counterexamples." That is, he means to show the inadequacy of "nothing-buttery" with his examples. I heartily approve of efforts at generating counter-examples but when we are lacking criteria for deciding when debunking occurs and to which account it occurs, no example can be regarded as an unambiguous counterexample. The criteria for deciding when debunking occurs are among the criteria we need to recognize counter-examples!

In addition to the above general problem, there is a specific problem with MacKay's examples. I have already shown that examples are irrelevant unless they deal directly with the case in hand. MacKay's prime example, an electric sign conveying an advertising message, just does not seem to involve "nothingbuttery."18 MacKay notes that, "no advertiser in his senses would imagine that be must deny the completeness of the electrician's account in order to defend the real presence of his message."19 MacKay is right. The reason the advertiser never thinks of attacking the electrician's account is that it (the electrician's account) is a lower level explanation of the sign which is compatible with the advertiser's account. The two accounts do not contradict and appear to stand to each other as overlapping levels of explanation. If this is correct, the example has no relevance to "nothingbuttery. "

We find then, that we are not really presented counter-examples, firstly, because MacKay has no criteria for identifying them and, secondly, because the examples we are offered do not fit the category. Thus, we are forced to conclude that MacKay's tactics against " nothing-buttery" are largely unsuccessful.

Complementariness and Complementarity

Nested and overlapping levels of explanation frequently complement each other. Science, purged of scientism, presumably nests within or overlaps Christianity for the compatibilist and it is very natural to see science and Christianity as complementary from within this perspective. In fact, this view seems almost mandatory. MacKay extends rather than breaks this compatibilist pattern, raising the idea of "complementary" to the status of a new logical category which he calls "complementarity."

Fifty years ago, the word "complementary" used of ideas simply suggested the ideas completed or rounded out each other. Bohr's use of the term to describe the wave-particle duality of quantum physics introduced new connotations. Especially when the word "complementarity" is used, these new connotations are unavoidable.

Attempting to explicitly state the new connotations, it is surprising to find that Bohr never defined "complementarity."20 Unfortunately, the lack did not prevent him and other21 from applying the word outside of physics. To be sure, Bohr had a problem. The intense drive toward unity so characteristic of science since the Greeks was pushing him to see the new pattern as no unique thing but as a general modus operandi for the universe. The drive that has produced the great unifying principles in science is exactly the same as that which leads to reductionism and scientisms. Therefore, it may well be that scientisms and science cannot be separated in terms of motivation and intent. Bohr felt a need to show the new principle was not peculiar but sensible and necessary. He has, however, left us with an unfortunate precedent.

"Complementarity" in quantum physics shares with complementary" the basic denotation of "necessary for completion." The wave picture and the particle picture are both necessary to understanding the full range of behaviors. Together, they explain the whole range. Paradox is unique to complementarity. The two pictures cannot be simultaneously true but what is the sense in seeing one as true at one time and the other as true another time? Nevertheless, we are apparently compelled by repeatedly confirmed experience to accept the paradoxical situation as true. Note that the use of two paradoxical pictures is empirically necessitated.

MacKay uses both "complementary" and "complementarity"22 as terms relating science and Christianity. His use of the latter is very much his own 23 and those who are familiar with the word only in the context of the physical sciences will be confused unless they are aware of the alteration it has undergone in his bands. Unfortunately, it is no easier to decide what differences MacKay sees between the two words than it was with Bohr. This much is clear. For MacKay, "Complementarity stands ... for a particular kind of logical relation distinct from and additional to traditional ones like contradiction, synonymy, or independence; it demands to be considered along with others whenever there is doubt as to the connection between two statements. . . ."24 Differences in viewpoint and standpoint lead respectively to what MacKay terms "hierarchic" and "non-hierarchic" complernentarity where the wave-particle duality is non-hierarchic and the relation of science to Christianity is hierarchic. There does not appear to be an obvious relation between these categories and the types of levels of explanation.

Might "nothing-buttery" and Christianity be complementary in this sense of logical complementarity? As for Bohr, so for MacKay, complementarity is to be invoked when empirical necessity arises. Since we surely want to insist there is more to the story than " nothing-buttery" allows, do we then have the right to bring in Christianity to complete the incomplete picture painted by "nothing-buttery"?

To his credit, MacKay does not use complementarity this way. This tactic must be rejected if only because the two views are contradictory.

John W. Haas, Jr., has nicely evaluated MacKay's use of complementarity 23 so I will make only one further remark. The proposal of a new logical category is very brave and radical. As such, it is bound to draw fire and cause confusion. If in use, however, the new relationship can hardly be distinguished from an old one even to the point where the proposer uses the two interchangeably, surely there is room for doubt that anything new is really in use. The advantages of " complementarity" over "complementariness" are elusive.


To what extent do the ideas we have examined accomplish the three tasks (of defending the three propositions) and what can we do given these accomplishments? The first proposition, that science is distinct from scientism, is well established.

As to the second proposition, to drive a wedge between science and scientism, we have one argument of dubious import. if its problems can be overcome, we have a way of logically separating science from scientism. As I have noted, we need more than logical wedges but without some form of logical wedge, no other type of wedge will provide permanent separation of science and scientism.

The third task of showing that Christianity and science are distinct but compatible might be more fully carried out. The distinction between science and Christianity is well established with MacKay's five distinctions. However, MacKay's tactics for showing compatibility are confusing (if not confused) at times because of ambiguity in the use of the terms "levels of explanation" and "complementarity."

The idea of levels of explanation is a valuable one for viewing the relationship between science and Christianity. The challenge is to show compatibility between the two and to maintain it without unduly restricting the operation of either one. A great deal of effort has been expended in this direction but it is a continuing task. The complementary nature of views must be an important part of our thinking about Christianity and science but it does not seem necessary to claim to be using a new category of logic in order to do such thinking.


Donald M. MacKay, The Clockwork Image: A Christian Perspective on Science, InterVarsity Press, Downers Grove, IL (1974)
2MacKay, op. cit., p. 52.
3MacKay, op. cit., pp. 78-83.
John A. McIntyre, "A Pictorial Representation of MacKay's Argument for Human Freedom in a Mechanistic Universe," Journal ASA, Sept. 198 1, pp. 169-171.
Clifton J. Orlebeke, "Donald MacKay's Philosophy of Science," The Christian Scholar's Review VII (1977), pp. 51-63.
C. Stephen Evans, Preserving the Person-A Look at the Human Sciences, Baker Book House, Grand Rapids, (1977), p. 113.
MacKay, op. cit., chaps, 2 and 3. passim
8MacKay, op. cit., p, 88,
9MacKay, op. cit., p, 41.
10MacKay, op. cit., p. 72.
11MacKay, op. cit., p. 91.
12MacKay, op.
cit., p. 41.
13D.M. MacKay, Brains, Machines and Persons, Eerdmans, Grand Rapids, (1980), P. 19.
MacKay, op. cit., Clockwork, p. 92.
15MacKay, op. cit., p. 44.
16MacKay, op. cit., pp. 43-44.
17MacKay, op. cit., p. 41.
18MacKay, op. cit., pp. 43-44.
19MacKay, op. cit., p. 44.
20Max jammer, The Philosophy of Quantum Mechanics, John Wiley & Sons, New York (1974), p. 95,
21Jammer, op. cit., p. 88.
22MacKay, op. cit., Clockwork, p. 91.
23John W. Haas, Jr., "Complementarity and Christian Thought-An Assessment: 2) Logical Cornplementarity," Journal ASA 35 (1983), pp. 2w209.
24D.M. MacKay, "Complementarity in Scientific and Theological Thinking," Zygon, V. 9 (1974), p. 226.