Science in Christian Perspective

The Appeal (the Necessity?) of Complementarity
Richard H. Bube
Department of Materials Science and Engineering 
Stanford University Stanford, California 94305

From: JASA 35 December 1983): 240-242.

In his two articles on complementarity (Journal ASA 35, 145 and 203 (1983)) John W. Haas, Jr. has summarized some of the problems associated with using the concept of "complementarity" for science/theology interactions. The interesting feature of this discussion is that there are not that many choices. As Haas points out in his first paper, Christians have a choice among three options for relating science and Christian faith. They can adopt a conflict perspective in which it is believed that science and Christian theology say the same kinds of things about the same thing, one must choose which has demonstrated the other to be wrong in all the major cases where they appear to interact. They can alternatively adopt a compartmentalization perspective in which it is believed that science and Christian theology say different kinds of things about different things; this calls for a schizophrenic response toward life and meaning. If neither of these two perspectives is appealing, then some approach appears necessary in which it is recognized that science and Christian theology say different kinds of things about the same thing, both descriptions deal with the same reality, but tell us different things about it without inducing conflict or contradiction. The appropriate response to compartmentalization is integration. It is in the affirmation of this approach that the concept of complementarity is called into service. It is essential to note that it is complementary descriptions that are the focus of attention. Scientific descriptions are valid when scientific categories and methods of description are used, and theological descriptions are valid when theological categories of description are used. What should be the relationship between two descriptions in order for them to be called complementary? And what does this mean? Haas has enabled us to see the refinements that are necessary to answer these questions. In this Communication I give a brief overview of the issues. 

The application of the term "complementary" to two descriptions stems from the fact that any description of what is unknown must be given in terms of what is known, by telling what the unknown is like. It is in this sense that all scientific and theological models should be recognized as similes, metaphors, or allegories, as recently described at some length by Poythress.¹ If to the request, "Describe an apple for me," from one who has never seen an apple, I reply, "An apple is usually red like a cherry, juicy like a peach, and firm like a pear," I have used three similes. Each is partially truthful, but none is totally truthful by itself. By knowing all three similes I know more about an apple than by knowing only one or two of them. If to these similes I add, "An apple is like a Japanese persimmon except that its inside is white rather than pink," I would know still more about an apple (provided that I was acquainted with Japanese persimmons), while still not knowing exactly what an apple is. Such simile descriptions could be multiplied many times over, giving a greater and greater awareness of what an apple is, but never converging on an accurate statement of what an apple is. Descriptions that are of partial or limited truthfulness (accuracy, exactness, correspondence with reality) may be said to be complementary.

Why do we give such complementary descriptions? There are two fundamental reasons that correspond to the "Classical Complementarity" and the "Logical Complementarity" discussed by Haas. Our everyday example of the apple illustrates both of these reasons. In the first place our descriptions are complementary because we are forced to use similes, metaphors, or allegories to describe the unknown in terms of,the known; such metaphorical descriptions are bound to be complementary. In the second place each of our descriptions focusses on a different range of categories of the apple: its color, its reaction with our taste sensors, its feeling to the touch, and its general appearance and texture, respectively. Since each description arises out of a different category of description, it again follows that their contributions must be additive, and that the individual descriptions can be properly viewed as complementary. We can give a few examples of these two reasons for formulating and types of complementary descriptions to illustrate.

Limitations on the Known to Describe the Unknown

The first reason that it becomes necessary for us to use complementary descriptions is that we do not have the needed "tools" among the known to adequately describe the unknown with a single model or description. Reality in all it complexity is not apprehendable by the human mind. Particular models give particular insight into the nature of reality, but they of necessity convey partial and incomplete truth. It follows that more than one model is needed to encompass the full dimensions of reality.

This kind of complementary description usually arises in the context of science and Christian theology when descriptions are selected from the same area (science or Christian theology) as the phenomenon to be described. Thus scientific metaphors are used to describe scientific phenomena; and theological metaphors are used to describe theological phenomena. The classical example from within science is the description of an electron as a particle, and the description of an electron as a wave. The concept "particle" and the concept "wave" are drawn from our macroscopic experience. When we attempt to apply these macroscopic similes to the microscopic world of the electron, we are enabled to say what an electron is like, but not what an electron is. I do not think that we need to invoke the Indeterminacy Principle or the interaction between the observer and the observed to make this point. If we could invent a sufficiently ingenious model that would transcend the macroscopic concepts of "particle" and "wave," then we might be able to resolve the complementarity between "particle" and "wave" by arriving at a model more faithful to the properties of an actual electron; perhaps in time we will find such a model. Until then we recognize that it is significant to state than an electron behaves like a macroscopic particle when its trajectory in vacuum under an applied electric and/or magnetic field is considered, but that an electron behaves like a macroscopic wave when it interacts with crystalline matter in the phenomenon of diffraction.

Biblical inspiration does not deliver us from the limitations imposed by the necessity to describe the unknown in terms of the known. What biblical inspiration secures is the assurance that the models so presented will indeed provide us with reliable partial truths. The theological models within which we describe the relationship between God's election and human responsibility (or between predestination and free will, or between determinism and free will as applied to human beings) provide us with useful and partially true representations as long as we remember their limited nature (their complementary character). Just as the question, "What is an electron like?" cannot be answered without knowing the answer to the correlated question, "What kind of experiment are you talking about?" (since the answer would be "Like a particle" if one were considering motion in a vacuum, but it would be "Like a wave" if one were considering diffraction from a crystal), so also the question, "What does the Bible teach on the relationship between God's sovereignty and human responsibility?" can be answered only if we know the content of the question. If the question is, "Does God have to wait for human beings to act before He can accomplish His purpose?" the answer is no. But if the question is, "Must a human being commit him/herself to God in order that God's purpose may be accomplished through them?" the answer is yes. From God's perspective His sovereignty is unquestionable; from the human perspective our responsibility is equally unquestionable. What is the cause of this situation? Our human concepts of sovereignty, election, determinism, responsibility, predestination, free will etc., to say nothing of our human concepts of time and interaction, are sufficiently limited that we cannot construct with these human concepts alone a single fully adequate description of the Divine Dynamics of life. Because of this, the biblical writers by inspiration have provided us with several complementary models in order that we might not be misled (in order that we might not believe, by analogy, that an electron is really a particle which just looks like a wave once in a while, or that an electron is really a wave which just looks like a particle once in a while, i.e., that God really "runs the show" without our involvement and our sense of responsibility is only an illusion, or that God's sovereignty is really reducible to His foreknowledge of what we in our free will do).

Another familiar example within the Christian context is the biblical teaching on the atonement. Here the biblical writers invoke a whole series of different similes in order to convey in some sense as much of the true nature of the atonement as it is possible to do when limited to the categories of everyday human experience. Thus the biblical writers tell as that the atonement is like healing and wholeness (salvation), like being bought back from slavery (redemption), like recovering from estrangement (reconciliation), like triumph over the Devil (victory), like having a legal debt paid by another (sacrifice). Each of these models tells us something true and reliable about the meaning, purpose, and accomplishments of the atonement; our understanding of the atonement is enriched by considering them all, yet never can be expected to encompass the totality of the atonement. These are complementary biblical descriptions of the atonement.

Are the complementary statements describing biblical doctrine exactly the same kind of statements as those describing the properties of an electron? Perhaps not. But their origin is the same; the limitations imposed on us when we try to describe the unknown in terms of the known.

Descriptions Drawn from Different Realms of Discourse

Descriptions must be given within a particular realm of discourse. Thus the color of an apple can be described by a variety of similes, but always within the categories of the color spectrum. Another occasion for the development of complementary descriptions arises quite independently of our limitations on describing the unknown in terms of the known: the limitations that we ourselves impose on a description by choosing its context in a particular set of categories.

This kind of origin for complementary descriptions can also be seen within a particular discipline, for example, science. In fact the various branches of science, extending from physics and chemistry to sociology through biology, botany, zoology, psychology and many others, each define the domain of its own description. The claim that there is only one domain within which a valid description can be given is known as reductionism and philosophically finds little support. Thus a description of an event in the life of a living creature can be given in terms of the physics of the event, the chemistry of the event, the biology of the event, the psychology of the event, and the sociology of the event, if we choose to remain within the scientific sphere as a whole. We do not expect these different kinds of description to give the same information, but neither do we expect them to contradict one another. Rather we expect them to be complementary. Phenomena involving human beings must be described scientifically with contributions from all these different domains; the goal is to integrate them into a total perspective.

The questions that we ask and the context in which we ask them may limit the appropriate categories of the responding descriptions. If we ask for the appearance of a classic painting, but insist that our answer must come from what we see when observing it with a microscope (thereby limiting ourselves to a narrow range of interpersonal categories), our response is quite different from what would be given if we stood back twelve feet from the painting and saw it within its full context and human correlations. The two descriptions that we would offer in this way might very well be said to be complementary since they apply to the same object but are drawn from different realms of discourse, as dictated by the examination procedures prescribed.

Now it is evident that descriptions drawn from the realm of science and descriptions drawn from the realm of Christian theology come from different realms of discourse. That there exists a viable description from the realm of science does not a priori mean that no viable description from the realm of theology can be given; conversely, that there exists a viable description from the realm of theology does not mean that no viable description from the realm of science can be offered. Because of the orientation of the two realms, science being a subset of the disciplines of which theology is the most completely integrating, there may well be special cases where no scientific description can be given (e.g., miracles), whereas there are no cases in which theological descriptions would not be appropriate.

In this sense, then, it appears that we may meaningfully speak of scientific descriptions and theological descriptions having the capability of being complementary: when they deal with the same phenomenon of reality and when they give descriptions of that phenomenon out of their own realms of discourse using categories and methods appropriate to those realms.

It is helpful to realize that we use the term "complementary" in a number of different ways, and for two basic reasons. We need to realize that the "complementary" descriptions offered are not identical when responding to these two different reasons. We may indeed debate whether one should say that science and theology arc complementary, but it does not appear that there is any debate that scientific descriptions are often complementary to theological descriptions of the same events. If this were not the case, what other option do we have?