Department of Mathematics and Physics
Trinity Western College
Langley, British Columbia V3A 4119
From: JASA 37
(March 1985): 11-18.
Most Christian scientists currently appear to favor a "realist" view of scientific theories. Apparent conflicts between science and Scripture are then generally resolved by modifying either our reading of Scripture or the offending scientific theories. In this paper we examine a third possibility: the adoption of an instrumentalist approach to scientific theories. This alternative enables one to make use of the practical results of scientific theories while at the same time withholding any commitment as to the validity of their epistemological content.
The instrumentalist considers theories primarily as "useful fictions" that are of great value in summarizing, manipulating, and predicting observations, and is more concerned with their ultimate utility than in their veracity.
we choose between two competing theories, both of which claim to be in accord with Scripture? In short, how can we be sure that a "Scripturally true" science is any nearer to the truth than secular science when its assertions go beyond observation and Scripture?'
The nature and status of scientific theories have in the last half century been the focal point of much discussion by philosophers of science. Such writers as Popper, Kuhn, Lakatos, Feyerabend and others have argued that theories cannot be logically derived from the observations but are primarily the product of a scientist's creative imagination; that scientific theories are equally unprovable, equally improbable and equally undisprovable; and that the acceptance and rejection of theories is heavily dependent on our prior philosophical presuppositions.
Given the subjective nature of scientific theorizing, and the inability of demonstrating conclusively the truthfulness or falsity of any particular theory, one may well wonder whether it is not more prudent to withhold assertions of truthfulness with respect to any scientific theory. Hence in this paper we would like to examine a third alternative to the resolution of the conflict between science and Scripture: the adoption of an instrumentalist approach to scientific theories. The instrumentalist distinguishes between observational data-the factual basis of science-and scientific theories which purport to "explain" or extend the data. He (the instrumentalist) considers theories primarily as useful fictions" that are of great value in summarizing, manipulating, and predicting observations, and is more concerned with their ultimate utility than in their veracity.
The French physicist-philosopher Pierre Duhem (1861-1916) traces the instrumentalist position back to Plato's (427-347 B.C.) suggestion that astronomers should attempt to devise mathematical models that would "save the phenomena" of the planetary motions.2 This program was carried out by the Greek astronomers and culminated in the geometric constructs of Claudius Ptolemy (A.D. 85-165). In his "Almagest" Ptolemy adopted the anti-realist view that his astronomical theories were merely useful fictions enabling him to predict planetary positions. His only criteria in choosing theories were accuracy in "saving the phenomena" and maximum Simplicty.3 (However, Ptolemy was not entirely consistent: in "Hypothese Planetarum" he defends a realist view of theories.)
The rival, "realist" interpretation of theories was advocated by Aristotle (384-322 B.C.). He believed that theories should not only save the phenomena, but should also be in accord with the actual nature of things. Thus his followers rejected Ptolemy's system because it was incompatible with the principles of Aristotle's physics (e.g. one of Ptolemy's devices was the 1. equant," which yielded non-uniform circular motions rather than the ideal uniform circular motion preferred by Aristotle). Moreover, in Aristotle's cosmology the planets were embedded in solid crystalline shells centered on the earth. This did not accord well with Ptolemy's system of epicycles (small circles rotating about a point on a larger circle) and eccentrics (circles not centered on the earth).
The interpretation of Ptolemy's epicyclic and eccentric spheres as being merely mathematical fictions was continued by Proclus (410-483 A.D.) in the fifth century. Similar views were held in the sixth century by Simplicius and John Philoponus. Later the non-realist position was supported by the famous Jewish philosopher Moses Maimonides (1135-1204) and Thomas Aquinas (1225?-74?), among many others. These writers all believed in the validity of Aristotle's physics and thus reconciled their acceptance of the Ptolemaic system by reverting to nonrealist interpretations of astronomical theories. It was held that earth-bound physics could discover the true nature and causes of the objects with which it dealt but that only God could comprehend the true movements of the heavenly bodies.4
A more thorough rejection of realist interpretations was favored by the later medieval nominalists.
Throughout the middle ages philosophers were much concerned with the relationship between reason and Revelation. Such figures as Augustine, Anselm, and Aquinas attempted to demonstrate the reasonableness of Christian beliefs. This led, for example, to rational 11 proofs" for the existence of God. The scholastics were inspired by the belief in the rational unity of philosophy and theology. They thought that true knowledge could be attained through human reasoning.5
The nominalists, most notably William of Ockham (1300?-1349?) and his followers, objected to such realism. In particular, they objected to the high role granted to human reason. As Dijksterhuis puts it:
They criticized the too exalted Position which the systembuilding doctors (e.g. Aquinas) had, in the opinion of their successors, assigned to human reason in their theology. Criticism was levelled first and foremost at the intellectualistic character of the Thomistic synthesis, in which human reason claimed to be able to conceive at least some of the truths of religion by its own efforts.6
Ockham insisted that we cannot acquire knowledge of any reality beyond the data of our experiences. He thus formulated the famous rule-Ockham's razorthat entities are not to be multiplied unnecessarily. He opposed the postulation of theoretical entities that had no observable consequences. Religious truths were held to be undemonstrable, the objects of faith alone. He believed that it was both impossible and unnecessary to prove these rationally.7 Thus the possibility of a natural theology is denied. In reacting against the rationalism of the scholastics, the nominalists inspired Martin Luther, who hailed Ockham as his master.8
Nicolas of Cusa (1400-1464) extended the concept of nonrealist theories from astronomy to physics. He maintained that only God is capable of grasping the true essential nature of any part of the universe. Man can never know the true causes and essences of things. Thus he can deal only with fictitious conceptions and causes.9
The conflict between realist and nonrealist views of astronomical theories intensified after the publication of Copernicus"'De Revolutionibus" in 1543. Coperni cus (1473-1543) himself was a realist but Andreas Osiander, in the preface to Copernicus'book, presented the theory merely as a useful calculating device:
".. the author of this work has done nothing blameworthy. For it is the duty of an astronomer to compose the history of the celestial motions through careful and skilful observation. Then turning to the causes of these motions or hypotheses about them, he must conceive and devise, since he cannot in any way attain to the true causes, such hypotheses as, being assumed, enable the motions to be calculated correctly.... For these hypotheses need not be true or even probable; if they provide a calculus consistent with the observations, that alone is sufficient.... So far as hypotheses are concerned, let no one expect anything certain from astronomy, which cannot furnish it, lest he accept as the truth ideas conceived for another purpose, and depart from this study a greater fool than when he entered it. "10
And indeed, Copernicus also had to resort to a large number (48) of epicycles to "save the appearances. " He could hardly have considered these to be in any sense 11 real", although he undoubtedly did believe that the earth really moved.11
For the next forty years the majority of astronomers continued to adhere to a nonrealist view of astronomical theories." Gradually, however, the realist view gained prominence. This led to the well-known conflict between those who rejected the Copernican systemprimarily on the basis of Scripture-and those who accepted the truthfulness of it. A third approach, the instrumentalist position, was advocated by Cardinal Bellarmine as a means of resolving the clash between Galileo and the Church." In a letter to Father Fosearini, who had written a book advocating the Copernican system, Bellarmine wrote:
". . . For to say that the assumption that the Earth moves and the Sun stands still saves all the celestial appearances better than do eccentrics and epicycles is to speak with excellent good sense and to run no risk whatever. Such a manner of speaking suffices for a mathematician. But to af firm that the Sun, in very truth, is
John Byl is Associate Professor of Mathematics and Physics at Trinity Western College, where he has been since 1978. Before that he taught physics at Dordt College (1977-78) and did research in astronomy at the University of British Columbia (1973-77). His Ph.D. is in astronomy from the University of B.C. (1973). He has published a number of papers in the areas of galactic structure, celestial mechanics, relativity, and the interaction between science and theology.
at the centre of the universe and only rotates on its axis without travelling from east to west, and that the Earth is situated in a third sphere and revolves very swiftly around the Sun is a very dangerous attitude and one calculated not only to arouse all Scholastic philosophers and theologians but also to injure our holy faith by contradicting the Scriptures. . . . "14
Marin Mersenne (1588-1648), an active propagator of the new science, was able to retain his religious
The conflict between realist and nonrealist views Of astronomical theories intensified after the publication of Copernicus' "De Revolutionibus" in 1543.
"Thus the instrumentalist philosophy was used here ad hoc in order to provide an escape for the theory from certain contradictions by which it was threatened."26
JOURNAL OF THE AMERICAN SCIENTIFIC AFFILIATION
Werner Heisenberg, another founder of quantum mechanics, was also convinced that his quantum theory27 led of necessity to an instrumentalist position.
To conclude our brief historical sketch, it is evident that nonrealist views of science have been advanced throughout the history of philosophical thought. Often
The instrumentalist position permitted the affirmation of the epistemological primacy of Divine revelation and stressed the limitations Of unaided human reason while, at the same time, making use of the practical results of scientific inquiry.
they arose in reaction to attacks on religious truths by scientific and philosophical speculation. The instrumentalist position permitted the affirmation of the epistemological primacy of Divine revelation and stressed the limitations of unaided human reason while, at the same time, making use of the practical results of scientific inquiry.
In recent years the instrumentalist position has not been well received by Christians. The great majority of Christians appear to be "realists" with regards to scientific theories. In fact, what is striking among current Christian writers is that instrumentalism is usually not even considered as a viable option. The Christian geologist D.A. Young, for example, concludes his study on the interpretation of the creation days:
"Indeed, if it can be demonstrated beyond doubt that Scripture demands a 24 hour view of the days, then the Christian scientist must accept that and, in effect, give up geological science and turn to something else. If he is consistent in his faith in Scripture he must do this."28
Likewise, the theologian Langdon Gilkey writes:
"anyone who uses the science of geology to find oil or coal has already implicitly abandoned the literalist view of Scripture." 29
Both of these writers are "realists" insofar as they feel that one should not
make use of those scientific theories that one considers false. The
instrumentalist has no such qualms. Indeed , consistency in faith does not
prohibit the use of convenient, but false theories as-long as they are clearly recognized as such. The utilization
relations (e.g. between
geological formations and oil deposits) efficiently summarized and predicted by
secular geology-or, for that matter, Flood geology-does not compel us to
subscribe to their theoretical explanations involving alleged events in the distant
A major argument raised against instrumentalism is centered on the successfulness of certain theories. Sure
ly, the realists exclaim, the great success of a theory in its empirical predictions confirms its essential truthful
ness. How could science be so successful in its empirical predictions if its theoretical structures are potentially
Such optimism is not, however, justified by history. To take a prime counterexample, consider the case of
Newtonian mechanics. Never has there been a more useful and successful scientific theory. Many scientists
in the 18th and 19th century were absolutely convinced of its essential correctness, with William Whewell
(1794-1866), the English scientist and philosopher, going so far as to insist that Newton's laws of motion
were to be considered as necessary truths.30 Yet today, after the advent of relativity and quantum mechanics, it is generally acknowledged that Newtonian mechanics is, strictly speaking, false. Granted, its empirical successfulness-within a limited range of experience still renders it immensely useful. But the nature of its basic theoretical concepts (e.g. time, space, mass, etc.) differs fundamentally from those of modern physics.
Or consider the fate of 19th century aether theories. Again, these were tremendously successful in their
empirical predictions. So much so, in fact, that the great physicist J.C. Maxwell (1831-79) remarked that
the aether was better confirmed than any other theoretical entity in natural philosophy.31 Few contemporary
physicists would still endorse this assessment.
History is replete with further such examples. For an account of more of these cases, along with a detailed
rebuttal to this objection against instrumentalism, the reader is referred to Larry Laudan's article "A Confutation of Convergent Realism."32 It is clear, then, that false theories can have true observational consequences and that therefore the successfulness of a theory is no guarantee of its truthfulness.
It has been argued that, since most scientists are realists, we must take realism seriously. Historically, the quest for truth has provided a powerful incentive for scientific theorizing. The notion that a scientist's own particular theory is true, while those of his competitors are false, has inspired many a scientist. In scientific theorizing the concept of truth is a prominent-many would say indispensable-psychological factor.
However, we must also take into account the fact that most scientists-with notable exceptions-are generally philosophically unreflective and, hence, not always fully aware of the subjectivity of their own (often tacit) assumptions and criteria. Furthermore, the concept of truth, while providing a powerful impetus, has proven to be a poor guide: as mentioned above, most theories once held as true have later been rejected as false.
Does one have to be a realist in order to be a good scientist? Would an instrumentalist philosophy of science hamper the progress of science, as is sometimes asserted by supporters of realism? Such fears appear to be unfounded. Instrumentalism has been advocated, in various forms, by many eminent scientists, including Ernst Mach, Pierre Duhem, Henri Poincare, Gustav Kirchhoff, Heinrich Hertz, Percy Bridgman, Werner Heisenberg, Arthur Eddington, as well as Niels Bohr and others who adhere to the Copenhagen interpretation of quantum physics.33 This strongly suggests that serious scientific investigation can well be undertaken without adopting a realist view of scientific theory. To cite one example, the instrumentalist epicyclic approach of Ptolemy was much more successful in predicting planetary positions than was Aristotle's realist cosmology.
In a recent series of articles in the Journal of the American Scientific Affiliation," Walter Thorson has voiced a number of further objections to instrumentalism. He feels that:
"If we accept operationalism (a form of instrumentalism) as an adequate epistemology of science, then I see no reason why we must not accept it as an adequate epistemology of Christian faith and life."35
Thorson comes to this conclusion because he sees a fundamental similarity between Scriptural and scientific knowledge. In Scripture, as Thorson points out, we find no basis for the idea of an abstract knowledge of spiritual truths. Rather, knowledge requires obedience (i.e. functional application). Thus theology (or "theory") provides the basis for practical living. Dr. Thorson finds a parallel in science, particularly in Michael Polanyi's account of scientific knowledge. For Polanyi stresses that in science there is no abstract knowledge, but only personal knowledge that entails a personal commitment and functional application.37
However, even if there do exist some similarities between Scriptural and scientific knowledge, we must not overlook the great differences in their content and origin, as has been well pointed out by J. C. Keister. " In Scripture we are given extra-experiential knowledge in the form of propositional truths that are to be accepted as the infallible word of God the Creator, who knows all; in science fallible man strives to rise above his
if modern man has now finally come to the realization that the human intellect has severe limitations in its ability to attain objective truth, then this should be cause for rejoicing rather than concern.
observational horizon by creatively inventing theories to account for his perceptions of nature.
But is not nature also a Divine revelation? Certainly, and hence we can expect our observations of nature, God's general revelation, to be consistent with the contents of Scripture, His special revelation. Unfortunately, however, this Divine sanction can not be extended to scientific theories. To be sure, God has given us brains and has created the universe so that the laws of deductive logic are applicable. Yet our reasoning ability is not confined to the mere application of deductive logic, but includes also the capacity for abstract, speculative thought-the source of scientific theory. It is a tool that can be manipulated by our inner desires. As such it can easily be misguided-"For out of the heart come evil thoughts" (Matt. 15:19)-and we are urged to "Take every thought captive to obey Christ" (II Cor. 10:15). Clearly, then, man is responsible for his thoughts, and hence also their products: scientific theories.
Thus Divine authorship may be bestowed on nature but not on scientific theories. This is made clear also by history: if God really were the author of our scientific theories then we would hardly expect to encounter false theories.
Dr. Thorson fears that the modern positivist attack on the concept of an objective reality will adversely effect Christian beliefs:
"This entails not only the death of science but also the final erosion of all concepts of an objective authority to which meaningful commitments could, even in principle be made, i.e. Christianity would become, even more than at present, incredible.... Emphasis on "cool," non-verbal forms of communication, which can totally distort factual truth in favor of subjective impressions, can make it almost impossible to present the word of God !18
I heartily concur with Dr. Thorson that Christian beliefs take for granted the existence of an external objective reality: the Biblical events must surely be considered to be real, rather than mere existential symbols. But the acceptance of an instrumentalist view of science does not compel one to deny the existence of an objective reality, it merely questions the ability of scientific theorizing to acquire knowledge of that reality. The last 400 years has seen a steady inflation of man's assessment of the power of human reason-at the expense of Biblical authority. If modern man has now finally come to the realization that the human intellect has severe limitations in its ability to attain objective truth, then this should be cause for rejoicing rather than concern. A clear recognition of the smallness of man is the first step towards the acceptance of the Christ of Scripture as the only road to truth and salvation. The Christian must proclaim that in the word of God alone can we find a meaning to our lives, a guide for our conduct, and absolute truth regarding reality.
Is the instrumentalist position consistent with Scripture? Two motivations for doing science are often distilled from the Bible. The first of these is the cultural mandate found in Gen.1:28, where man is exhorted to subdue and have dominion over the earth. The emphasis is, however, on applications rather than on a quest for truth. CertaiDly, man must first investigate nature before he can develop and regulate it. Scientific research is essential if he is to acquire an intimate understanding of nature: man must make extensive observatioDs, he must engage in experimentation, he must search for patterns and regularities, etc. And this will all involve theorizing. Yet the text implies that man's ultimate task in science is not to speculate on a reality beyond the observations, but to provide useful results.
A second motivation is often derived from those texts (e.g. Ps 19, Rom.1) stating that God reveals Himself through nature. But the purpose of this revelation is primarily redemptive (i.e. that we may recognize and acknowledge God as the Creator) and the knowledge thus revealed is limited to impressions of God's power, beauty and grandeur. Due to the corrosive effects of sin, even this limited revelation appears dim in the eyes of man and special revelation-in the form of Scripture and the inner working of the Holy Spirit-is needed for us to perceive it fully. Moreover, this revelation is made manifest via our direct observations of nature and not through our theoretical speculations. God does not reveal Himself through our scientific theories. On the contrary, Scripture emphasizes the limitations of human thought: job 38-41 stresses man I s ignorance regarding origins and deeper questions regarding nature; I Tim.6:20 warns us to avoid the oppositions of science-or knowledge-falsely so called, etc. Rather, it is Christ "in whom are hid all the treasures of wisdom and knowledge" (Col.2:3).
In summary, I can find nothing in Scripture that speaks against an instrumentalist view of science. Indeed, instrumentalism, with its more modest appraisal of the power of human reason, appears to be more Biblical than scientific realism. God is certainly not glorified if our faith in scientific theories causes us to distort His Word, which is the great danger with realism.
the instrumentalist approach is applicable only as long as our prime goal is
that of utility. Some fields of study (e.g. sociology and psychology) are
concerned not only with observing and predicting human behavior, but also with
transforming it to preconceived standards. Here theories can have significant
ethical consequences. The Christian must therefore insist on the authority of
Biblical norms and insights on the nature of man. Other disciplines (e.g.
history and philosophy) have truth as their main goal. There we have no choice
but to be realists: reject those theories that contradict Scripture and seek
In conclusion, I feel that the advantages of the instrumentalist approach to scientific theories have not been sufficiently appreciated by the Christian community. Instrumentalism appears to avoid the shortcomings of the other two major proposals for reconciling science and Scripture: subjective, ad hoe modifications of either Scripture or science. Instrumentalism, on the other hand, enables us to retain the epistemological supremacy of Scripture-thus leaving us with a solid basis with regards to the essentials of the Christian faith-while still making use of the practical results of secular science.
1. These difficulties are discussed in more detail in my paper "Science and Christian Knowledge," Reformed Perspective, Vol. 2 No. 6 (April 1983), pp. 4-9.
2. Pierre Duhem, To Save the Phenomena, translated by E. Doland & C. Maschler (Chicago: University of Chicago Press, 1969), p. 5.
3. Ibid., P. 17.
4. cf. E.H. Madden (ed.), Theories of Scientific Method (Seattle: University of Washington Press, 1966), pp. 23-25.
5. Meyrick H. Carre, Realists and Nommalists (London: Oxford University Press, 1946), pp. 120-122.
6. E.J. Dijksterbuis, The Mechanization of the World Picture (London: Oxford University Press, 1961), p. 165.
7. Leszak Kolakowski, Positivist Philosophy (Harmondsworth: Penguin, 1972), p. 23.
8. As cited by Carre, op. cit., p. 122.
9. cf. Madden, op. cit., p. 25.
10. As quoted by Arthur Koestler, The Sleepwalkers (Harrnondswortb: Penguin, 1968), pp. 573-574.
11. Ibid., p. 454.
12. Ibid., p. 170.
13 . Ibid., p. 29.
14. as quoted by Madden, op. cit., pp. 44-45.
15. cf. Kolakowski, op. cit., p. 30.
16. Pierre Gassendi, "Exercises Against the Aristotelians," Book 11, Exercise VI,
as found in Craig B. Brush (ed.), The Selected Works of Pierre Gassendi 1977), p. 144.
(New York: Johnson Reprint Corporation, 1972), pp. 85-86. 29. Langdon Gilkey in Science and Religion, I.G. Barbour (ed.), (New York:
17. cf. Karl R. Popper, Conjectures & Refutations (London: Routledge, 1963), Harper & Row, 1968), p. 167,
P. 98. 30. William Wbewell, Philosophy of the Inductive Sciences (London: John W.
18, cf. W.T. Jones, Hobbes to Hume (New York: Harcourt, Brace & World, Parker, 1847), vol. 1, pp. 245 ff,
1969), p. 281.
19. Pierre Duhem "Physics of a Believer," included as an appendix in his book
The Aim and Structure of Physical Theory (Princeton: Princeton University Press, 1954), pp. 273-311.
20. Kolakowski, op. cit., p. 178. 34.
21. Gordon H. Clark, The Philosophy of Science and Belief in God (Nutley, September, pp. 129-138.
New Jersey: The Craig Press, 1964), p. 7.
22. Ibid., p. 93.
23. Clark in Horizons of Science, Carl F.H. Henry (ed.), (New York: Harper & Row, 1978), p. 271.
24. cf. R.T. Weidner & R.L. Sells, Elementary Modern Physics (Boston: Allyn & Bacon, 1968), pp. 180-183.
26. Popper, op. cit., p. 82.
27. Werner Heisenberg, Dialectica 2, p. 333 ff.
28. D.A. Young, Creation and the Flood (Grand Rapids: Baker Book House.
31cf. Larry Laudan, "A Confutation of Convergent Realism" in Philosophy of Science, 48 (1981), p. 27.
32. Ibid., pp. 19-49.
33. cf. Popper, op! cit., p. 99.
34Walter R. Thorson, ]ASA (1981: March, pp. 3-11; June, pp. 65-73.
35. Ibid., p. 134.
36. Ibid., p. 133.
37. J.C. Keister, JASA (1981), September, pp. 138-141.
38. Thorson, op. cit., p. 9.