Science in Christian Perspective



The Clockwork Image Controversy (I)

Department of Physics
The King's College
Briarcliff Manor, N.Y. 10510

From: JASA 28 (September 1976): 123-125.                              MacKay responds

Donald M. MacKay in his book The Clockwork Image argues that determinism as a scientific hypothesis does not imply "moral determinism and that the conclusion that man is nothing but a complex machine is erroneous. Reasons are given for my belief that the arguments of the book are fallacious. Additionally, the dangers of any attempt to simply begin with his conclusions, as assumptions are indicated. In particular, the inadvisability of following MacKay in a rejection of Occam's razor is discussed and an argument is made for the necessity of Occam's razor in Christian apologetics.

I have been noting for some time now the reactions of Journal ASA book reviewers and my acquaintances to Donald MacKay's book The Clockwork Image. Most reactions have been favorable although I have detected occasional uneasiness. Few reactions have been unfavorable. My reactions fall in the last category as my letter in the June 1975 issue of the Journal ASA indicated. Unfortunately, my letter seems to have been more brief than lucid, and consequently I wish to discuss MacKay's arguments more fully and to explain more clearly those points at which I believe he is in error. The points at issue are sufficiently basic that the discussion should be of value in its own right.

MacKay's Argument

For the information of those unfamiliar with the book and as a reminder to those who have read it, I shall begin with a synopsis of Dr. MacKay's argument. This will also provide, not accidentally, a means of judging my impartiality and perceptiveness.

MacKay's intent is to provide an apologetic for the Christian confronted by "moral" determinism and "nothing-buttery". He recognizes materialistic determinism's insistence that men are nothing but elaborate machines as a threat to the reality of moral choices. In order to meet this threat, he argues in the following manner.

MacKay distinguishes determinism, as a scientific hypothesis identified with the doctrine of causality ("all physical events have physical causes"'), from ,.moral" determinism. This separation is achieved by first reminding us that modern physics has raised doubts about the universal applicability of causality. His main defensive position, however, is an argument leading to the conclusion that even if causality enabled accurate prediction of our behavior, such predictions would not be binding on us as we make choices. Thus, MacKay believes moral responsibility is compatible with scientific determinism and "moral" determinism is discredited.

If the argument thus far is correct, "moral" determinism is out but "the clockwork image" still remains. Therefore, MacKay directs his attention to "nothing-buttery," which is his term for the reductionistic doctrines of materialistic determinism. He claims that " nothing-buttery" results when scientific techniques are applied beyond their proper limits. His main defense

MacKay's conclusion that multiple and equally valid accounts of the universe are possible, amounts to a direct denial of Occam's razor (the law of parsimony.)

against "nothing-buttery" occupies the greater portion of the book. It consists of efforts to support the conclusion that "the 'nothing-buttery assumption-that when you have verified a complete account in one set of terms you automatically debunk any others-is simply mistaken logic".2 These are the essentials of MacKay's position.

I have sketched MacKay's argument in what seems to me the best possible order but the reader ought to be warned that the book's structure seriously obscures this order. The book is a collection of texts of talks given over a period of time and that in part accounts for the infelicitous organization of the material.

I am disappointed that MacKay does not elaborate on the proper limits of science. In view of secular opinion that either there are no limits to the scope of science or reality is confined to what is scientifically knowable, it would seem that an elaboration is mandatory when the existence of limits to the applicability of scientific techniques is claimed. To be sure, MacKay does advance what he believes are examples of items of human emotional experience lying outside the realm of scientific examination, He seems dangerously unaware of the strength of materialistic and positivistic arguments against these examples. This failure to understand the force of opposing arguments is a constant feature of the book.

Scientific and Moral Determinism

The claim that scientific and "moral" determinism are separable may be true, but MacKay does not demonstrate it. The argument be adduces to support his claim involves the alteration in brain state occurring when a subject is informed of a prediction made by an observer. Intending to separate the two forms of determinism by exhibiting a situation where the two forms do not coexist, MacKay assumes scientific determinism holds in the above situation and attempts to show that "moral" determinism does not. He argues that the perturbation in the subject's brain state produced by being informed of the prediction either is sufficient to make the prediction untrue or, if the predictor were clever enough to adjust his prediction to account for the expected perturbation, the subject would still not be in the predicted state (and therefore not in error) after choosing opposite to the prediction. Thus, MacKay claims that the subject is not bound by the prediction and "moral" determinism does not occur in this situation.

I find three mistakes in this argument. (1) Scientific determinism is equated with predictability. Determinism is not even in principle equivalent to predictability (for remarks on this and an interesting discussion of free will and determinism, see the Mathematical Games section of the March 1974 issue of the Scientific American). (2) Most importantly the question is begged by assuming the subject may choose to believe or not to believe the prediction. The issue is precisely whether or not inescapable predictions are possible; to assume a choice is available to the subject is to decide the issue out-of-hand. (3) The situation used is defective. This may best be seen by asking what the proper conclusion would be if a perverse human subject falsified every prediction. If we conclude that the subject is therefore morally free, what will we say of a wholly determined computer made to play this same game under the orders that it always choose opposite to prediction? Also, if in the above contest with the computer the predictor was allowed to keep a secret record of what he really thought the computer would do, his record would be found later to have been perfectly correct. If the same thing were done with the perverse human subject, what should we then conclude about the determinedness of the subject's choices? The difficulty is that the relation of predictability to "moral" determinism is not clear.

By publishing this book, InterVarsity Press has performed a disservice for undergraduates similar to giving front line troops defective weapons.


The argument against "nothing-buttery' takes the form of an illustration whose conclusion is expanded to cover the desired territory. MacKay introduces an electric sign saying, "Bongo is good for you". He notes that we can explain the sign in terms of electrical circuits in general and the circuit of this sign in particular, or alternatively we can explain the sign in terms of its message and the purposes of the men who created it. Both explanations are clearly valid and mutually compatible. Thus, he concludes that "the ,nothing-buttery' assumption-that when you have verified a complete account in one set of terms you automatically debunk any others-is simply mistaken logie".2

The last step is either an argument by analogy or by unwarranted (and disputed) assumption. The analogy is: the electric sign can be explained in mechanistic terms and/or in terms of the meaning of words and the purposes of men, and likewise man and the universe can be explained in mechanistic terms and/or in terms of the meaning of life and the purposes of God. MacKay concludes that both types of description are equally valid.

For argument by analogy to succeed, the things compared must be shown to be sufficiently similar for the purposes of the argument. MacKay fails even to attempt the necessary demonstration. It is clear enough that the terms of the analogy are not simply equivalent. The purposes of God differ from those of men even in essence, and the word "meaning" has different meanings as applied to life or to words (if we admit that words have meaning, does it follow that existence has meaning?). If we allow the analogy, can MacKay's conclusion then be sustained? No, because another mistake is involved.

To the secular mind both explanations of the electric sign are basically mechanistic, although the meaning of the sign supposedly requires a more complicated mechanical explanation than does the mere circuitry. This is after all what "nothing-buttery" is all about. It is not admitted that the two explanations of the electric sign are really explanations in two different sets of terms. The example does not support the conclusion then unless "nothing-buttery" is false. The conclusion is assumed in the course of the argument and we find once again a circular argument.

Occam's Razor

Now I want to examine MacKay's conclusion. He has not, as I have tried to show above, arrived at it properly but is it nonetheless acceptable? I think not. His conclclusion that multiple and equally valid accounts of the universe are possible, amounts to a direct denial of Occam's razor (the law of parsimony). If a complete explanation of the universe in one set of terms is indeed available, Occam's razor forces us to reject as superfluous any more complicated set of terms that might also comprise a complete explanation. It was on this basis, in part, that the Copernican system overthrew the Ptolemaic system. Occam's razor is two edged in that it not only requires the rejection of a more complicated explanation when a simpler one will do, but it also requires a more complicated explanation when a simpler one will not do. This law is so essential that I suspect it is a necessary part of thinking in much the same way that two-valued logic seems to be. It is certainly part of the thinking cap of the modem scientist and to reject it would seriously reduce the common ground on which we must stand in any attempt to witness to fellow scientists as well as increase any contempt they may feel for our intellectual respectability.

With respect to any conflict between science and religion, rejection of the law of parsimony has well-known tragic results. Science and religion then occupy their own separate (MacKay uses the confusing term "complementary') niches and are equally true. They cannot conflict because they cannot contact. Religion becomes useless baggage to the scientist, although without Occam's razor the scientist is no longer forced to throw out that baggage. The universe becomes the two-storied universe which Francis Schaeffer has criticized. Let me give an example of the effect of this in operation. Responding to MacKay's essay "From Mechanism to Mind", John Beloff remarked,

It would indeed be presumption on the part of an agnostic like myself to challenge MacKay on points of Christian doctrine or biblical exegesis. If he assures me that Christianity is quite compatible with the truth of Mechanism or Materialism, I am quite happy to take his word for it, but be must not complain if he has increased my suspicion that Christianity (at least as professed by someone at MacKay's level of sophistication) is compatible with anything at all.4

By publishing this book, InterVarsity Press has performed a disservice for undergraduates similar to giving front line troops defective weapons. We must retain the law of parsimony for it is actually our first line of defense and not an impediment. It is the law of parsimony that compels us to conclude from the fact of the resurrection that the scientific description of the universe is in fact not complete, and it is the law of parsimony that demands another explanation. It is clear that that search will require greater and better efforts than we have yet expended.

1Donald M. MacKay, The Clockwork Image, InterVarsity Press, Downers Grove, IL 60515, p. 13

21bid., p. 72.

3J. R. Smythies, ed., Brain and Mind, 1965, pp. 186-190 41bid., pp. 194-195