Science in Christian Perspective

Theological Clues from the Scientific World*
HAROLD P. NEBELSICK

Louisville Presbyterian Theological Seminary
1044 Alta Vista Road
Louisville, KY 40205

From: PSCF 38 (June 1986): 110-121
*An earlier version of this paper was read at a conference on "Positive Contributions of Science to Christian Theological Understanding," October 12-14, 1984, sponsored by the Institute for Theological Encounter with Science and Technology (TTEST), St. Louis, Missouri.

The theories of Relativity and Quantum Physics, as illustrated by the discoveries of Albert Einstein, Werner Heisenberg, and Niels Bohr, offer epistemological implications which indicate that the world does not necessarily exist as we usually see it and/or think about it. Rather the most profound aspects of nature are apprehended and understood by means of intuitional insights that are enabled to probe an order more profound and more comprehensive than that which we usually comprehend.

Insights from Gunter Howe and Carl Friedrich von Weizsdcker suggest that the methods of discovery and understanding in natural science are applicable to the science of theology as well. If so, these two "sciences" may well mutually modify and complement one another so as to assist us in possibly rethinking reality as a whole.

Beginning with the scientific revolution in the seventeenth century and with the technological revolution in the eighteenth century, natural science and technology have done more to reorder and change our world and our lives in it for good and for ill than any other single force. The year 1776, important as it is as the birthdate of a nation, is perhaps more important as the year that James Watt invented the first viable steam engine. With it he ushered in the scientific-technological age, the age which, according to British historian Herbert Butterfield, has done so much to alter our world and our lives that only one other movement in history, the rise of Christianity, may be compared to it (B OS, p. 190). Since the beginning of the seventeenth century, however, with the exception of Newtonian scientism, theology in general has tended either to oppose or to ignore natural science as such.

Fortunately, in our time, there is a growing awareness of the importance of natural science for theology and indeed for the faith that theology is supposed to guide. Already some 40 years ago, the German theologian, Professor Karl Heim, saw something of the writing on the wall.

It was a disastrous turning point in the history of Protestantism when Protestant theology shortly after Schleiermacher cut itself loose from its link with philosophy. Since then it has more and more withdrawn from the difficult task of placing the world view of faith over against that of un-faith. It thereby satisfied itself with the task of extracting the central theme, the Heilsgeschichte (salvation history) from the total picture of reality, which picture every believing person must have if he is to act responsibly within this world ... Theology then proceeded to develop this central theme in every direction thinking it could confidently leave everything else to the profane sciences. (H GN, p. 26)

Hence, the re-interest of theology in science that, after Heim, has been and is being represented by such persons as Giinter Howe (Mensch und Physik), Carl Friedrich von Weizs5cker (Zum Weltbild der Physik), A. M. Klaus MUller (Die Prilparierte Zeit), Thomas F. Torrance (Christian Theology and Scientific Culture), Stanley Jaki (The Relevance of Physics), Mary Hesse (The Structure of Scientific Inference), Ian Barbour (Issues in Science and Religion), Arthur Peacocke (Science and the Christian Experiment), and to a certain extent Wolfhart Parmenberg (Theologie als Wissenschaft), and my own Theology and Science in Mutual Modification, to name a few, is of indispensible import for theology as such. The main point of the dialogue that is now beginning in a serious way between theology and natural science, is, as I see it, not the ethical dimension, important as that is, but the question of epistemology, i.e., How do we know what we know? and How do we go about learning what we need to know?

In the comparatively short compass of this paper, I want to refer to four theories that have redirected natural science and changed our world and much of our thinking with it. In that these theories have implications not only for natural science, but for knowledge in general, they are affecting and will inevitably affect theology as well. The first two are from Albert Einstein, the third from Werner Heisenberg, and the fourth from Niels Bohr. All three are Nobel Prize winners. Together they have changed the face of modern physics and with that they have changed our perception of reality.

The Relevance of Relativity

In 1905, the then obscure clerk in the Patent Office in Bern, Switzerland, Albert Einstein, published his paper, "On the Electro-Dynamics of Moving Bodies," in which he spelled out his Special Theory of Relativity. Some twenty years previously, in 1887 to be exact, Albert Michelson and Edward Morley were faced with one of those beautiful experimental failures which are so essential for progress in natural science. The experiment was contrived to verify the existence of the so-called "ether"-that invisible property which was supposed to permeate all space and all matter and through which the earth as well as all other cosmic bodies were thought to move in much the same way as we move through the air when we move on earth. just as we feel the air resisting our motion when we run at a rather rapid rate so, it was thought, the ether should cause a drag on any object moving against its flow. That being so, there should be a measurable differentiation between the velocity of a ray of light propagated in the direction of the earth's movement as it orbited around the sun and that of a ray of light propagated in a direction at right angles to the direction of the earth's orbit.

In order that a precise comparison might be assured, Michelson and Morley set up their apparatus to split a single ray of light in half. They directed one half of the ray in the direction of the earth's movement to give opportunity for the "flow of the ether" past the earth to retard the light ray. They directed the other half at right angles to the first. In spite of repeated experiments Michelson and Morley found that the two rays generated from the split beam of light persisted in giving them identical readings on their interferometer no matter in which direction the rays were propagated. Their consistent failure to detect anv difference in the velocity of the two rays of light used in the experiment caused Michelson and Morley to doubt that the experiment had been performed correctly. Subsequent experiments right up until 1930 continued to corroborate the data of the 1887 experiment.

It is not certain whether or not Einstein paid any special regard to Michelson and Morley's experiments

Harold Nebelsick is Professor of Doctrinal Theology at Louisville Presbyterian Theological Seminary in Louisville, Kentucky. He holds a B.A. degree in Philosophy from the University of Nebraska, a B.D. degree from San Francisco Theological Seminary and a Ph.D. degree in Divinity from the University Of Edinburgh. He has done post-doctoral study at Princeton, Gi5ttingen, Berlin, Basel and Paris and is a member of the Advisory Committee of the Center of Theological Inquiry, Princeton. His books, Theology and Science in Mutual Modification (1981) and Circles of God, Theology and Science from the Greeks to Copernicus (1985) are studies of the interface between Theological Science and Natural Science.

at the time. It is certain, however, that he had a better idea. In one of those fantastic flights of intuition which have marked the revolutionary theories of natural science from its beginning, Einstein theorized that, rather than light varying in velocity relative to the movement of either its source or its target, the velocity of light is invariant. Further, he postulated that that invariance had to be understood as the basis of all physical measurement. The fact, for instance, that the velocity of light is constant, independent of the motion of its target or its source (and since "velocity" means so much space is traversed in so much time, i.e., 60 miles per hour = 1 mile is covered in I minute), would mean that space and time are to be understood in relation to the velocity of light and relative to one another. Whereas space was considered three dimensional, time added a fourth dimension so that space-time became a four dimensional continuum.

If Einstein's Special Theory of Relativity challenged our usual conceptualities, his 1915 General Theory of Relativity compounded the challenge.

In addition, since the velocity of light is constant in relation to all moving objects, it followed that absolute motion had to be ruled out. In fact, according to Einstein himself, the "principle of relativity" in its widest sense is contained in the statement: "There is no absolute motion" (E OLY, p. 41). Thus the motion of any particular object must be measured relative to the distinct frame of reference or coordinate system that, at the time of measurement, is being considered as the base from which the measurement is being made. In addition, because the laws of physics apply equally to all coordinate systems, any one frame of reference is as good as any other for valid measurement.

Einstein was not the first to develop a theory of relativity, of course. In a posthumously published paper in 1703, the Dutch physicist Christian Huygens worked out "a principle of relativity," a principle now referred to as "the Galilean principle of relativity" to distinguish it from that of Einstein. Huygens too recognized that there is no way of establishing the real (or absolute) velocity of any moving object since the measuring of velocity means measuring one object as moving relative to another and given that all objects are in motion (Sch 11 AE, pp. 506-7). Einstein's theory of relativity, however, based as it is on the universal invariant character of the velocity of light, made it clear that even though observers experience different states of motion the laws of physics retain their validity under differing states in question. It is therefore of interest to note that, in print, Einstein frequently referred to his own theory as the 11 so-called relativity theory" (H SSP, p. 57). In letters to close associates he preferred the name Invariantentheorie, which name stresses the notion that the varying observational data are explained by the invariant laws that derive from the theory (H SSP, cf. Sch I AE, pp. 253f ).

To elaborate, since light moves at a constant speed of 300,000 kilometers (186,000 miles) per second no matter what the velocity of its source, its direction, or the velocity of its destination, any inertial (non-accelerating) coordinate system is as good as any other as a basis for measuring the velocity of objects that are in movement in relationship to them. The velocity of all objects is measured relative to the particular co-ordinate system which the observer of the object chooses to use as the base of measurement. All measurements and all observations therefore are relative to the position in relation to which the measurements or observations are made. As Henry Margenau has stated:

To achieve objectivity of basic description, the theory must confer relativity upon the domain of immediate observations. (Sch I AE, p. 254)

Here we will simply have to pass by the other equally important aspects of Einstein's 1905 Special Theory of Relativity such as the interpretation of space and time, the removal of the principles of simultaneity and action at a distance, and even the formula, E = mC² that relates mass to energy, powerful and fateful as it is. Like the basic Invariantentheorie itself, however, these show us that the world does not necessarily correspond to the ways in which we have been taught to think of it, nor does it necessarily correspond to our intuitions or our sense impressions. Consequently, while we hold to what we know tenaciously, we must also be prepared to alter our understandings of reality when evidence, which we recognize as being true, forces a change in our conceptions.

If Einstein's Special Theory of Relativity challenged our usual conceptualities, his 1915 General Theory of Relativity compounded the challenge. The theory is based on the equivalence of gravitational and inertial fields. The theory combined space and time into a single space-time continuum according to Gaussian (rather than Cartesian) coordinates and shaped the continuum according to Riemannian geometry which prescribed that all lines be curved. The theory was given its first substantiation by Sir Arthur Eddington's expedition in 1919 which sought to test the theory by measuring the path of light rays emitted from distant stars, rays that passed near the sun during a solar eclipse. As Einstein had predicted, stars, which if measured rectilinearly were behind the sun, could be seen when the moon blotted out the sun's corona during the eclipse, because the sun's gravity acted as a lens and refracted, i.e., curved the light rays from the stars around it. It is now thought therefore that the universe itself, following the pattern of light coming from distant stars, is shaped according to the gravity of the bodies of space.

In a word, it was no longer possible to know exactly what the outcome of basic physical processes would be in all particulars.

This gives rise to the concept of a finite universe in which all lines, rather than extending outward to infinity as in Euclidean geometry and Newtonian science, eventually come back on themselves. The universe is thus finite, a closed continuum, rather than infinite. When this is correlated with the theory of the red-shift first introduced by the astronomer Edwin Hubble in 1929, according to which the galaxies are rushing outward from one another, there arises the fascinating concept of the expanding finite universe conceived in terms of the curved space of Riemannian geometry and according to Gaussian coordinates that include time. The universe is thus finite but unbounded (W FTM, p. 30). Its bounds are ever expanding in time. At what for us are its outer limits, i.e., at the limits furthest away from the galaxy of the Milky Way of which our solar system is a part, the universe is expanding at nearly the velocity of light. Whether or not it will continue to expand forever or will someday pause, stop, and begin to contract, depends, according to present theory, upon whether or not there is enough matter in the universe to generate an amount of gravity sufficient to overcome the inertia of its present expansion.

From the epistemological point of view, it is important to realize that both of Einstein's theories of relativity not only demonstrate that our fundamental knowledge of reality is subject to change, but also that it is by way of simplification, by unifying previously disparate understandings, that new understandings of reality come about. In the Special Theory of Relativity, based on the speed of light, time and space have become integral concepts and the principles of energy and momentum have been united into one principle. In the General Theory, the principles of energy and gravity are focused into a single principle (Cf. Sch I AE, p. 61). Both follow "Ockham's razor, 11 a principle that is as old as the pre-Socratic Pythagoreans and which we may state as follows: "The simpler the answer that explains the known phenomena, the more likely it is to be true. "

As a result of Einstein's theory, Newton's concept of light as corpuscles was again recognized, along with Huygens' understanding of light as traveling vibrations or waves. In 1924, the French physicist Louis de Broglie advanced the theory that not only light but other manifestations of energy-like electrons could be considered as having particle-like or wave-like aspects with equal validity. Light, for instance, showed itself to be in particle form or in wave form, depending upon how the energy was measured. If one set up an apparatus which measured light as a stream of particles, it registered itself as photons. If one set up an apparatus which measured light as waves, it registered as undulatory motion. After experimentalists who found that electron beams exhibited similar dual behavior confirmed de Broglie's theory, scientists became aware of what seemed to be a basic contradiction in nature. Nature appeared either as particulate in structure or as undulatory motion depending upon the experiment that was set up to observe it.

A further advance in quantum physics that served to confuse our usual understandings of the way things are was introduced by the Gbttingen physicist Max Born who, in 1926 when theoretically interpreting electron collisions, found that the trajectory of the individual electrons was not predictable. If one were to direct an electron from an emitter to a good-sized target, it was possible to predict that the electron would hit the target, but, as far as the observer could judge, there was a distinct lack of accuracy. The exact trajectory of the electron could not be known in advance nor could its place of impact be predicted. Further, its trajectory could not be retraced after the experiment was finished. Taken in aggregates, the electrons acted more like shotgun pellets than like rifle bullets. Although it was not possible to predict which electron would bit which place on a target, it was possible to trace the pattern of hits. The pattern made by the aggregate could be predicted but individual impacts could not. From this data Born developed the statistical interpretation of electron collisions that was based on the observation that individual electron behavior could not be predicted but given a great enough number of instances, a predictable pattern would result.

For de Broglie, since electrons appeared under some conditions as waves and under others as particles, there was no way of designating the exact properties of electrons with certainty. For Born, when electron scattering was treated as consisting of particles interacting with a target, there was no way of knowing which

The only way, therefore, that "proof' of the existence of an object in science may be demonstrated is for the scientist to explain the experiment under which the observation and measurement has taken place.

Thus, on the one hand, physics moved away from the classical sense of objectivity-we know exactly what things are. And on the other, it moved away from determinacy-if we know the present position, velocity and trajectory Of any particular object, we can know and predict the exact future velocity, trajectory, and position of that object. In a word, it was no longer possible to know exactly what the outcome of basic physical processes would be in all particulars. That is, the present state cannot be derived exactly from the past nor can the future state be predicted in all particulars from the present. "Natural laws" in quantum physics, therefore, are expressed statistically, which means that the future courses of events can be "predicted" only if sufficiently large quantities of them are taken into consideration. It is on the basis of such evidence that people such as Giinter Howe (H MP, pp. 64 ff.) and Carl Friedrich von Weizsdcker (W ZWP, pp. 332 ff.), and A. M. Klaus Mfiller (M PZ, pp, 293 ff.) were and/or are convinced that there is a principle of non-determinacy at the heart of nature itself.

Non-determinacy as a principle goes back to 1927 when Heisenberg at GiAtingen propounded the indeterminacy relation with regard to the velocity and location of electrons. Heisenberg found that, if in an experiment one were to set up an apparatus to measure the position of a particle, it was possible to show the particle's location. Further, he found that, were one to set up the apparatus for measuring the momentum of a particle, one could measure the momentum. However, it was an eitherl-or affair. Not only was it impossible to measure both the location and the momentum of a particle at the same time, but in addition the more precisely one measured the momentum of a particle, the less precisely one would be able to measure its location and vice versa. Hence, simultaneous measurement for location and for momentum was impossible. The measurements were mutually exclusive.

To repeat, the problem which Heisenberg set about to solve was the simultaneous measurement of both the location and the momentum of an electron as it moved from source to destination. He found that simultaneous momentum-place measurement was impossible; for the more accurately the experimenter measured the one, the less accurately he or she could measure the other.

Consequences of Complementarity

The next short but very important step in the quantum physical understanding of nature was taken by the Copenhagen physicist, Niels Bohr, Heisenberg's teacher. At the Physical Congress held in September 1927, at Como in Italy, Bohr advanced Heisenberg's principle of indeterminacy by propounding the "theory of complementarity. " The theory took Heisenberg's principle of indeterminacy one step further and insisted that both the "momentum picture" and the "location picture" are necessary complements of reality. Although it is impossible to know velocity and location simultaneously-i.e., although the measurements are actually mutually exclusive-both are equally necessary to the understanding of reality as a whole: hence the principle Of complementarity.

With this, of course, absolute identity between measurement and object, between concept and reality, was severely questioned. The procedure approaches the phenomena-noumena distinction of Kant but is even more elusive. According to Kant, we can not know reality in itself-its noumena. We only know the appearance of reality-its phenomena. Thus, the wave-particle dichotomy that resulted from de Broglie's discovery of the wave-particle nature of massenergy was compounded by the location-momentum dichotomy that resulted from Heisenberg's experiments. just as the wave-particle dilemma raised problems of the identity of reality, so too, as Bohr pointed out, the fact that "we cannot know both the momentum and the position of an atomic object" raises some very real questions as to the attributes of the object itself (Sch I AE, p. 211). According to Bohr, reality that revealed itself only in a manner contradictory to observation had to be held together in the mind if some kind of wholeness were to be preserved.

As a result of this identity crisis which still persists in modern physics, we can no longer say that nature is such and such, we can only say that under such and such circumstances, nature reveals itself to be such and such. The only way, therefore, that "proof" of the existence of an object in science may be demonstrated is for the scientist to explain the experiment under which the observation and measurement has taken place. If the explanation is such that the scientist is able to persuade the scientific community of the validity of the procedures of the experiment in question and of the results obtained, and if these results can be obtained by successive experiments, the scientist is said to have proven the point. In a word, the procedure of gaining knowledge affects the knowledge gained. Any automatic one-to-one relationship between "seeing" and "knowing" no longer holds. Proof is an agreement of minds that have followed similar procedures in discovering a certain matter. We re-learn to know reality according to the theories that are judged to best explain it, theories that are substantiated by experiment.

Subject-Related Reality

Further, in the experiments that demonstrated the impossibility of simultaneously measuring both the momentum and the location of a particle, it became clear that the result obtained depended upon the scientists' decision as to which of the two aspects Of reality the scientist intended to measure. The decision in turn determined which of the two phenomena the experiment would reveal. The scientist set up the apparatus according to preference and, if all went well, the object involved showed itself to the scientist according to the scientist's intentions. It showed him or her what be or she was looking for. Hence, we find ourselves in a situation where, according to our best understanding, in the very process of experimentation,

Since science is on the move, should theology marry it today, theology might well be widowed tomorrow.

there is the influence of the observing mind (by the choice of measurement technique) upon what may be observed. Matter thus reveals itself to us according to the way we are set up (i.e., programmed) to observe it. This means that, as we can no longer say that nature is absolutely determined, so we can no longer say that it is possible to ascertain the properties of nature independent of the decisions of the scientist. Objectivity results when all scientists who choose to perform a certain experiment in the same way will, if all goes well, get similar results, results that are recognized as valid by the scientific community.

To return to the principles of indeterminacy and complementarity, it is, for instance, according to Heisenberg, Bohr, Howe, von WeizsLicker, and Mijiler, most important to realize that the inability to fix the momentum and position of a particle simultaneously is not a failure of ability on the part of the scientist. This lack of momentum-position coordination is, according to the aforementioned thinkers, due to the nature of nature itself. Nature at the atomic or sub-atomic level is of locatable stuff or it is of speeding stuff but not of both at the same time. If this is so, and if there is no third possibility (for which Einstein hoped and continued to work toward in his proposed Unified Field Theory until his death, believing, as he said, "Der Alte w0rfelt nicht" ["God doesn't play dice"]), then we are faced with the fact that it is human intervention which allows the experimenter to observe and thus to know distinct aspects of reality. As von Weizsgcker (W ZWP, pp. 48 ff.), Howe (H MP, pp. 69 ff.), and, following them, Millier (M PZ pp, 43, 132, 150, 172 et al.) have stressed again and again, in Heisenberg and Bohr's interpretation of quantum mechanics, we see at an extremely basic level-at the level of the composition of matter itself-that we do not stand in a neutral relationship to nature nor does nature stand in neutral relationship to us. Rather our knowledge of nature depends upon our interaction with it. With that, of course, the subject-object dichotomy of Descartes as well as a strict eitherl-or logic must be set aside.

Following von Weizsdeker, it may, therefore, be necessary for us to realize that we now have to do with complementarity at two different levels. Building upon Bohr's Theory of Complementarity, in which he held the mutually exclusive understanding of the location and the momentum of a particle together in the mind, von Weizsdcker has spoken of a concept of "circular complementarity," wherein it is necessary to allow our concepts of the different aspects of nature to be mutually and continually corrective. We must think of the one even as we focus on the other, or, hold on to the one as we "walk through" the other (WZWP, pp. 290 ff.). In addition, we have to do with a mind-matter circular complementarity, a complementarity in which mind and matter are partners in the selection-revelation process. As mind attempts to understand and conceive of matter, so matter determines the parameters of such conceptions.

The Dialogue Renewed

All of the above helps us to realize that natural science, which in the last century was so powerful in the construction of a materialistic, pre-determined, mechanical, machine-like, spirit-denying universe, has in our time rediscovered both the interaction between the conscious and the unconscious parts of nature and the limitations of the descriptive processes of science itself. The same physics that, according to Heim, was once one of the main forces drawing people out of the church and the Christian faith and leading them to put their faith in natural science, progress, scientific materialism and Corntian positivism, has now reversed itself and moved from determinacy to open-endedness. In the words of the physicist Pascual Jordan, "Physics, which once said, 'Nein,' to the faith, has now taken its 'Nein' back again" (Cf. H CA, p. 112).

This, of course, doesn't prove the faith, As von Weizsgcker has put it, there are two attitudes in relationship to science that are of no use at all to theology or the church. The first is a rejection and ignoring of the findings of physics by theology, as if theology only has to do with the realm of the spirit and has nothing to do with physical reality. The second equally unfortunate attitu~e is theology's complete acceptance and submission to the findings of natural science, followed by the attempt to apply these findings directly to the formulas of faith itself (W ZWP, pp. 262 f.). Since science is on the move, should theology marry it today, theology might well be widowed tomorrow.

Nevertheless, even as the closed-system, deterministic world view of the eighteenth and nineteenth centuries not only became a view of science but a world view which stretched far beyond science and into the thought structures of faith itself, so there is a possibility, at least, that a reversal may take place in many of the thought structures of faith as well. We may see the open-ended, non-determined, interactive mind-matter world view of natural science moving us beyond the subject-object dichotomy of Descartes that characterized not only classical physics but also Enlightenment philosophy and the theology based upon it. If so, the present dialogue between theology and natural science may well move us toward new thought constructs wherein the realities of faith and those of natural science will be understood as inter-related, interdependent, and complementary aspects of the totality of reality.

Scientific Hints for Theological Thought

Being more specific with regard to the clues that natural science has to offer theology, we may mention first that Einstein's theories of relativity give us a vivid illustration of the necessity, the place, and the process of theoretical thinking in relationship to both discovery and understanding. New "facts" are not reached by a process of deduction from what is known in the past, nor is understanding reached by a process of abstraction from experience. Rather, as Einstein has stated again and again, there is no truth and no meaning to experience without theory, a controlling concept, or what we refer to in theology as "doctrine" or "dogma." Theory, doctrine or dogma is not the result of experience, not abstraction from experience. Rather, they, like the fundamental axioms of geometry, are, as Einstein has reminded us, "free creations" of the

Any theology that is certain its answers are the truth, the whole truth and nothing but the truth, and forever the only truth, is in grave danger of ignoring the epistemological complexities Of human perceptual processes.

intuitive mind (E 10, p. 234). Such theories, doctrines, or dogmas, if valid, enable us to apprehend and interpret reality at profounder levels than has heretofore been possible. Once propagated, the new theories or doctrines are, in fact, formative of experience. Hence, they are prior to it. One quote from Einstein may suffice to illustrate this very important point.

The natural philosophers of those days [18th and 19th centuries] were ... most of them possessed with the idea that the fundamental concepts and postulates of physics were not in the logical sense free inventions of the human mind but could be deduced from experience by "abstraction --that is to say by logical means. A clear recognition of the erroneousness of this notion really only came with the general theory of relativity, . . . the fictitious character of the fundamental principles is perfectly evident from the fact that we can point to two essentially different principles, both of which correspond with experience to a large extent ... (Sch 1, AE, p. 273)

The laws of old, discovered and devised 
are nature still but nature methodized.

We may add for contrast:

The new laws of nature although devised
reveal nature, nature methodized.

We do not know reality as such beyond any remainder; we know it at all only as we "methodize" it into formulas that fit the reality being investigated well enough for it to show itself to us by the experiments that the formulas prescribe. Truth, then, is not a matter of tradition as such nor is it a matter of perception and experience as such. Truth comes about when we fit our perceptions and experience into known concepts, or when we alter our concepts or, if need be, exchange them for others that, according to our deepest convictions, more satisfactorily present reality to us than did the concepts that were once considered valid, Hence, both natural science and the science of theology are matters of educated, trained, perhaps changed and/or continually corrected perception. Truth is a matter of experience satisfying the categories of reality which we hold to be valid, categories that are tested and retested against the objects they seek to designate in a constant process of mutual modification between formula and designated object.

Relativity and quantum physics have replaced Newtonian physics; the latter may at best be considered to be a limited case of the former. Newtonian physics still works within a limited perspective. We are still quite 1. safe" in using Newton's second law (force equals the product of mass times acceleration) to predict the motion of hockey pucks, automobiles and even space-satellites. However when we attempt to deal with the extreme velocities and small masses of the sub-atomic world and/or the intense gravitational fields of the cosmos where space-time curvature is appreciable, then relativity and quantum physics must be employed if reality is to be represented with the degree of accuracy modern physics demands.

This simply illustrates again that classical Newtonian physics may be considered valid only if we ignore questions that are of a more ultimate nature than those which classical physics is prepared to answer. In physics as well as theology, as Paul Tillich has insisted, our concern must eventually be with that which is ultimate. Ultimately we who are Christian may want to understand natural science and theology as interpenetrating disciplines simply because both have to do with God's creation. Natural science attempts to know creation. Theology attempts to know God who is responsible for

Objectivity results when all scientists who choose to perform a certain experiment in the same way will, if all goes well, get similar results, results that are recognized as valid by the scientific community.

and reveals himself through creation. Following Einstein, who said, "Science without religion is lame; religion without science is blind" (E OLY, p. 26), so too theology without science is likely to be muddled and antiquated, and perhaps also somewhat empty and irrelevant.

With the integration of space and time as a consequence of the invariant velocity of light, and the integration of inertia and gravity in the theories of relativity, the space-time absolutes of the Newtonian physics, along with the space-time a priori categories of the understanding that Kant based upon Newton, are seen to be relative categories rather than absolute categories. They apply only within limited perspectives. Hence, important as was the pivotal role that Kant's thought played in the development of a modern mindset (Cf. N TSMM, pp. 63-71), we continue to follow his subjectivization of reality to our peril. There is no doubt that Kant's attributing to mind an active part in the knowing process was a helpful contribution to epistemology at the begimming of the eighteenth century Enlightenment. However, there would also seem to be little doubt that the absolutization of his system, which completely subjected reality to the knowing mind, began a process of individual subjectivization in philosophy, the negative impact of which is still being felt, especially in theology. With Kant, the Cartesian rejection of the heteronomy of authority, which subjected the self to external authority, reached finality with the autonomous self that subjugated reality to itself. It never seemed to have occurred to Kant that different minds with equally legitimate credentials would or could picture the world in different ways any more than it occurred to Newton, on whose physics Kant built his "metaphysics," that his model of the universe might be one of many. Kant would be equally astonished by the precision of current theory and experiment in confirming non-Newtonian models of physical reality.

Much of post-Kantian theology, therefore, which is built upon the Kantian epistemology and the world view of classical physics, including much of Bultmann and Tillich and even some of Barth along with those emphasizing Heilsgeschichte (salvation history) to the neglect of Weltgeschiche (world history), has to be rethought in the light of post-Newtonian and postKantian categories (Cf. W GN, p. 51). The "process theologies" that build on the scientific interest of Whitehead are aware of the necessity of continuing conceptual change and realize that the concepts of absolute time and space have to abandoned. In the light of modern science, however, such theologies need to rethink the relationship of experience to theory or doctrine. They need also to take seriously the ramifications of both the concept of the finite universe in relationship to transcendence and the problem of implicating God with time in a world in which simultaneity has been ruled out.

In this regard it is of first importance to remind ourselves of the epistemological implications of Einstein's disproof of space and time as absolute along with Heisenberg's theory of indeterminacy and Bohr's concept of complementarity. Together, these theories gave the lie to the Newtonian conception of the cause and effect predictabiltity nexus that, in classical physics, had eventuated in a deterministic view of nature for every individual object. Hence, although Einstein continued to maintain predictability as probability (Seb I AE, pp. 261 f.), modern physics insists that mechanistic determinism is pass~. Thus, the idea that anything or anyone is pre-determined to be and become the being or individual prescribed by precedents that follow unchanging natural law can now be considered as invalid, as can the view that nature is an independent, self-sufficient and self-enclosed system (H GT, pp. 62 f.). Modern science, therefore, allows room for the possibility of the interaction of God with humankind as well as for human freedom.

Any theology, therefore, that continues to accept the Cartesian subject-object dichotomy and divides the mind from the reality of the world, the rescogitans from the resextensa, which division entails a God-nature dichotomy such that any reference to God's activity in the world must necessarily be classified under the category of "myth," must be considered suspect. Equally, any theology that has an anti-miracle bias, because miracles are understood as abrogations of classical "natural law," may well have to re-think its basic conceptuality. Howe may well have had a word for today when he said that the modern physicist expects that the theologian will "begin with miracle and think out the consequences accordingly" (H CA, p. 49). On the other hand, in consideration of the finite nature of the world, any theology that follows Newton and fails to differentiate between God and nature, or any theology that follows the nineteenth century's subtly pantheistic or even panentheistic ideas should recognize that the thought structures on which they are based are anachronistic.

Until the end of time ... we must be satisfied to work with incomplete, partial answers, answers that, although they may be adequate for the life of faith for the time being, are never final in an absolute sense.

At the same time, any strident kind of "orthodoxy" that depends on once-for-all answers may well have to be called into question. As "natural law" changes with our perceptions of reality, so too our theological concepts may be subject to alteration. Because of both the imperfection and the limitation of humankind, to say nothing of the "wrong-headedness" of the human mind, we never possess perfect concepts of reality-be they our understandings of nature or our understandings of God. Therefore, any theology that is certain its answers are the truth, the whole truth and nothing but the truth and forever the only truth, is in grave danger of ignoring the epistemological complexities of human perceptual processes. It is this "whole truth" and "nothing but the truth" complex of theology, in contrast to natural science which at its best realizes its limitations, that too often causes particular theologies to treat its answers as absolutes. In doing so, theology often cuts itself off from the positive insights of thought patterns which, though different, may serve to correct its concepts of reality. Hence Howe, speaking from a continental point of view, could say:

Theology today often judges the liberal theology, magnificent as it was, after its own fashion, very harshly, while a physicist is more inclined to acknowledge earlier physics within the boundaries set for it by new theories and to honor it as "classical physics." (H CA, p. 46, n. 2)

In theology, as well as in natural science, we always work in a relativized observational context. This is true even in our attempts to allow biblical insights to guide us toward better understanding of the world and of God. In all knowledge we continue to search for those ever elusive invariant structures that will provide intelligibility and meaning with respect to the richness and multi-dimensionality of human experience. However, until the end of time when, as the Apostle Paul tells us, 11 we will know as we are known," when all things including our theological thought will be brought to completions, we must be satisfied to work with incomplete, partial answers, answers that, although they may be adequate for the life of faith for the time being, are never final in an absolute sense. These answers, although valid as far as we can judge, must also be seen as being possibly open to new formulation. Einstein has perhaps put this best in his obituary to Ernst Mach:

... concepts which have been proven useful in ordering things often acquire such authority as to seem "inevitable," "necessary," and even "a priori." If we remember their human origins, however, the conditions on which their usefulness and justification depends and their relationship to experience, then their "exaggerated authority" is broken. They may then be removed if they do not legitimate themselves, corrected if their correspondence with given experience was too careless, replaced by others if a new system which we prefer for good reasons can -be developed. (Phys. Zeitschr. 17, (1916), p. 101, translated and edited for simplification)

The quest for deeper understanding, whether in the science of nature or in the science of theology, is of utmost seriousness. We enter it with our whole being. As Michael Polanyi has pointed out so cogently, "Truth is something that can be thought of only by believing it" (P PK, p. 305). When we assert what is true, we do it with universal intent. We submit ourselves to it. Out of the quest for truth itself, a firmament of standards comes into being which, in turn, becomes the tradition we respect and the culture of which we are a part (P PK, pp. 300 ff.).

Tenaciousness in the cause of truth is absolutely essential if natural science andl or theology are both to be preserved and to progress.

Tenaciousness in the cause of truth is absolutely essential if natural science and/or theology are both to be preserved and to progress. It is in this way that natural science and theology are always seeking new understanding. In both disciplines, concepts, theories and doctrines are constantly being tested and are perhaps being re-understood. They may even pass in and out of their ranges of validity. Old systems of thought may be replaced by new if, as we have quoted Einstein as saying, a new system can be developed for good reasons. It is the "good reasons" that constitute the rub. These can only arise if we believe what we are doing in natural science or in theology has indeed to do with truth.

Polanyi has compared the recognition of truth to the Apostle Paul's understanding of redemption. Faith demands the impossible of us. It demands perfection. The pursuit of the unattainable, however, is rewarded by grace in which the believer is given that which is beyond attainment. So the scientist who surrenders himself or herself to the constructs of reality, posed in problem form, is rewarded with an understanding which seemed beyond the possibility of his or her own realization (P PK, p. 324). The good reasons, in the light of which we may justify theological changes, then, are those which arise when the grace of truth bits us with its inevitability. Then and only then can we justify giving up old persuasions. Our reasons will then show bow the new realization of truth has come about, as well as how the new understanding modifies, puts a new perspective upon, and makes a limited case of the old, once certain persuasion.

The change of perspective, the giving up of one, once valid and perhaps still revered concept for a new one is of the nature of scientific thinking itself. In the words of von Weizsgcker:

Science demands of us again and again the offering up of old convictions for better insights. The least important student can stand up against a Newton or an Einstein. (W ZWP, p. 189)

Doubt, then, as to the formulations of either science or the faith is not the antithesis of truth. Both belief and doubt, as Polanyi has said, are inherent in knowing. Our search for truth, in fact, necessitates doubt. if this were understood then perhaps the faith itself might be so transformed as to be again meaningful to humankind (P TD, p. 92).

In considering the relationship of faith and doubt it is helpful, as T. F. Torrance has pointed out, to distinguish between beliefs that are held at "the bottom of one's heart" and those beliefs held at "the tip of one's tongue." The former type of beliefs is ultimate or fundamental to the existence of any science including the science of theology. These beliefs cannot be "proven." They are, however, truly rational for they are genuine personal responses to the rich multidimensionality of all human experience. The belief that the universe is intelligible, for example, is ultimate simply because one must assume it in any attempt to "prove it" and any doubt of it destroys the very possibility of doing science. Although such ultimate beliefs must be identified over and over again, once identified they are not to be doubted simply because they both make science possible and motivate and guide the scientific community's development of working beliefs. These in turn take form in the particular theoretical structures or working beliefs that are used to describe any restricted region of reality and, as such, they may be subject to doubt (T BSCL, pp. 19f).

Such working beliefs, like explicit scientific theories, are continually tested against experience, and this process brings about enhancement and/or modification or, should the "belief" fail, abandonment. Any healthy scientific procedure, therefore, will have fundamental beliefs that are held "at the bottom of one's heart" in addition to the working beliefs held at "the tip of one's tongue." The former give a basic structure to the quest for truth. The latter change as the evidence warrants. The line between the two, however, is never fixed, but the one will tend to alter, interpenetrate, and modify the other.

Thus, while formulas, theories, explanations, concepts, institutions, dogmas, and doctrines are necessary, no formula, no theory, no explanation, no concept, no institution, no dogma or doctrine is necessarily forever sacrosanct. They are good, justifiable, and valid as long as they continue to be transparent to the realities of the world on the one band and/or to the realalties of faith on the other. If and when reality begins to escape and move beyond the power of such concepts, when they no longer are able to focus reality for us, then those concepts must be called into question or they will call us into question.

For our part, it we find old accepted formulations adequate, we are morally bound to submit to them, On the other hand, if, according to our deepest convictions, we find that accepted doctrines are limiting or even false, we are under the constraint of the truth itself to correct them. We may, perhaps, even need to replace them with new conceptual structures that more accurately reveal reality, and hence generate a greater degree of understanding than did the once good but now less than adequate constructs.

Here the prayer, "We believe, Lord, help thou our unbelief," must be supplemented with the plea, "Help us to understand and so formulate the faith that we along with all humanity in the scientific-technological age may understand and believe. " Our hope in the possibility of being made aware of perhaps new and more adequate concepts and the ground of our courage is given by our trust in the God of truth who leads us into all truth (John 16:13).

On February 2, 1949, Einstein wrote an article in which he replied to his critics. After apologizing for expressing himself rather too sharply, he made an observation that may well be appropriate here as well: "One can really quarrel only with his brothers or close friends; others are too alien" (Sch 11 AE, p. 688). It is as friends in this new ecumenical age that Christians of all persuasions face the natural world and the faith together. With Anselm of Canterbury our motto is fides quaerens intellectum, "faith in search of understanding. "