4. What can we know? The Dialogue with Science
The most obvious fact that distinguishes our culture from all that have preceded it is that it is—in its public philosophy—atheist. The famous reply of Laplace to the complaint that he had omitted God from his system—“I had no need of that hypothesis”—might stand as a motto for our culture as a whole.
The vision of reality that comes to expression in Laplace’s system still dominates, if I am not mistaken, popular thinking today in spite of all the changes in science itself that have taken place since his time. It assumes that the real world is that which can be “scientifically” explained by laws of cause and effect that can be expressed in mathematical terms. Consequently, to quote Laplace, “An intelligence which knew at one moment of time all the forces by which nature is animated and the respective positions of the entities which compose it … would embrace in the same formula the movements of the largest bodies in the universe and those of the lightest atoms; nothing would be uncertain for it, and the future, like the past, would be present to its eyes.” As Polanyi has pointed out, the person who had this knowledge would know precisely nothing, since the knowledge of the atomic particles of which a thing is composed is not knowledge of the thing. The deceptive power of the formula is that it suppresses what Polanyi calls the tacit dimension of knowledge without which knowing is an impossible undertaking. We are interested in atoms and molecules only because of the part they play in the shaping of a world we know as human beings and before we know anything about physics.
Nevertheless, this Laplacean vision of reality still dominates popular thinking. It sustains “a universal tendency to enhance the observational accuracy and systematic precision of science at the expense of its bearing on the subject matter.” It leads to the delusion that when we have discovered the smallest units of which a thing is composed and the forces by which they are moved, we have understood the thing. And this delusion is enormously reinforced by the fact that in societies shaped by our culture the processes of manufacture, exchange, and government are conducted on these principles. A mechanical view of the nature of ultimate reality is made more credible by the fact that we live in a mechanically organized world.
We are familiar with the story of the long rearguard action fought by theologians against the relentless advance of this way of understanding the world. At point after point, attempts have been made to identify the places where the mechanical explanation breaks down and some kind of divine intervention has to be posited as the only explanation. But, as we well know, time after time the gap has been closed and the “God of the gaps” has had to retreat to another temporary refuge. Today the futility of this strategy is generally recognized, in spite of occasional efforts to find a place for divine intervention in the Heisenberg principle of indeterminacy. Theologians and believing scientists have in recent times sought rather a modus vivendi between science and religion by representing them as two different ways of seeing the same reality. The insights of gestalt psychology have been utilized to show that as the same objects can be seen in different ways, so the same phenomena can be understood in different but complementary ways so that there need be no quarrel between the two. The same person can be a scientist and a believer, and he can look at the same things in two different ways, depending on whether he is in his laboratory or in church.
It is difficult to remain content with this kind of peaceful coexistence. It is, of course, true that we sometimes see (to use the famous illustration) a picture of two human profiles as if it were a picture of a vase. It is true—in the more famous Indian parable—that one can see a piece of rope as if it were a snake. But no sane person is content to leave matters there. Unless we are to live in a world of make-believe, we will not be content until we have decided which it is—a rope or a snake. Having discovered what it is, we shall then be able to understand the different ways of seeing it—as a snake or as a rope. But we shall not be content until we have reached that point.
To be specific, the currently popular way of coping with the science-religion debate by regarding it as an example of two ways of “seeing as” is, I fear, only a particular manifestation of that dichotomy between the public world of facts and the private world of values about which I have spoken. Of course, if religion is construed in essentially mystical terms—that is, in terms for which the idea of purpose is not central—then there is no clash. The modern scientific world-view coexists peacefully and naturally with that kind of religion. But if we are talking as the Bible talks about God, who is Creator and Governor of all things, who acts in specific ways, and whose purpose is the criterion for everything human, whether in the public or the private sectors, then there is an inevitable conflict. Is it or is it not the case that every human being exists for the joy of eternal fellowship with God and must face the possibility of missing that mark, forfeiting that prize? If it is the case, it ought to be part of the core curriculum in every school. It will not do to say that the determination of character by the structure of the DNA molecule is a fact that any child must learn to understand, but that the determination of all proper human purposes by the glory of God is an opinion that anyone is free to accept or reject. The question of which is the real world simply cannot be permanently evaded. There can be no genuinely missionary encounter of the gospel with our culture unless we face these questions. For there can be no question that for the ordinary educated person in our society, the real world is not the world of the Bible but a world that can be explained, and is being more and more fully explained, without reference to the hypothesis of God.
In spite of all the vast changes in physics in the present century, the vision of the real world in the mind of ordinary inhabitants of our culture is the one derived from Newtonian science. Its essential features are something like the following: There is an infinite world of space that is at rest; it has existed and will exist without beginning or end. In this space there are moving bodies that continually interact at a distance in ways governed by the laws of inertia and gravity. All things that exist consist of such bodies, which are exceedingly small but are nevertheless real and finite things—be they molecules, atoms, electrons, or whatever. This is the real world. Clearly, it has many of the qualities traditionally ascribed to God—infinity, eternity, and absolute rest. In any case, it is the real world. It alone is what we have reliable knowledge of, what we have to do with, what we have to take account of.
We are familiar with the fact that this picture of reality has been drastically changed by a whole series of developments in the past hundred years, including Clark Maxwell’s magnetic field theory, Einstein’s special and general relativity, quantum physics, and the recent discoveries about the fundamental structure of matter. The new physics is so different from the old that those whose minds have been shaped by the old are almost unable to grasp the new except through long and thorough training. A nonscientist can only tread here with great caution. But some things even a scientifically illiterate theologian can grasp. The universe as modern physics understands it is neither infinite nor eternal. It has a calculable age and, according to the Second Law of Thermodynamics, is moving inexorably toward total entrophy, in which nothing that could be called matter will exist. Space and time are no longer two different forms of infinity, but space-time is a single finite entity—liable to “warping,” having a beginning at a calculable time-distance from the present, and having also a limit at which it ceases to exist. At this limit, the so-called singularity, space-time no longer exists, and the laws of physics no longer operate. Moreover, there is no “point of absolute rest” from which the universe could be surveyed. All points are relative to all others, and there is only one absolute, namely, the speed of light. Furthermore, the work done on the fundamental structure of matter has led into a world where entities that can hardly be called “things” in any ordinary sense operate according to principles that cannot be described in mechanical terms. There is no way in which the most fundamental elements in the structure of the atom as modern physics understands it can be visualized. Leptons and quarks, muons and photons are not pieces of matter in any imaginable sense. Nor is it possible to form any visual image of anti-matter. “Matter is an affair of changing relationships between non-material entities.” Neither the organic images of ancient Greek science nor the mechanical models of Newtonian science have any further validity. The only language that can be used is that of mathematics in a more and more abstruse form. And not even mathematics can provide us with an absolutely secure mental framework any longer, for—according to the famous Gödelian theorems that have never been disproved—within any rigidly logical mathematical system there are propositions (or questions) that cannot be proved or disproved on the basis of the axioms within that system, and consequently it is uncertain that the basic axioms of arithmetic will not give rise to contradictions. We are a very long way from the Newtonian world. Yet it is the Newtonian view that still largely shapes our culture, both its way of thinking and its way of organizing its public life.
At this point it is helpful to draw attention to two elements in the history of thought since the rise of modern science. The first is this. Both science and theology have been reluctant in recent decades to enter into the discussion of cosmology. Theology has been reluctant because it has shared in the general withdrawal of religion to the private sector. It was willing to discuss time and history because personal being is so intimately involved in time; but it was not interested in space. As we have seen, even its discussion of history was drawn toward a special Heilsgeschichte, separate from a so-called scientific history, which deals with events in space. Theology has tended to become anthropology, or rather psychology. On the other hand, science has until recently avoided cosmology for fear of becoming involved in metaphysical questions for which traditional physics has no answers. But today the advance of astrophysics has carried it to the limits of the universe and forced it to face cosmological questions that are ultimately metaphysical. Physics thus challenges theology in a new way to come out of its private enclave and say what it has to say about the world, about the single finite entity the physicists call space-time, within which it is impossible to isolate a “spiritual” world of time from a “material” world of space.
The other point is this. Studies in the origin and development of modern science have led historians to ask why the brilliant intellectual powers of the ancient Chinese, Indians, Egyptians, and Greeks, in spite of their achievements both in observation and in pure speculation, never brought forth the dynamic, self-developing science of the modern era. It has been very plausibly argued that the decisive factor is to be found in the biblical vision of the world as both rational and contingent. For to put it briefly, if the world is not rational, science is not possible; if the world is not contingent, science is not necessary. Let me put the point more fully: On the one hand, the enterprise of science would be impossible if there were no principle of rationality in the universe. If every instrument reading in a laboratory were simply an isolated happening that could not be connected in an intelligible way with other readings, the whole enterprise would be futile. But, in fact, a scientist faced with an apparent irrationality does not accept it as final, nor does he take refuge in the idea of arbitrary divine intervention. He goes on struggling to find some rational way in which the facts can be related to each other, some formula or mathematical equation that will tie them logically together. This struggle is a deeply passionate one, sustained by the faith that there must be a solution even though no one can yet say what it is. Without that passionate faith in the ultimate rationality of the world, science would falter, stagnate, and die—as has happened before. Thus science is sustained in its search for an understanding of what it sees by faith in what is unseen. The formula credo ut intelligam is fundamental to science.
But—and this is the other equally important fact-faith in the rationality of the universe would not sustain science without the concurrent belief that the universe is not necessary being but contingent being. Indian metaphysics has been totally committed to the rationality of the universe but has understood it as necessary being-part of the eternal cycle of evolution and involution. The universe is the emanation of Brahma, not the creation of a personal God. Its ultimate secrets are therefore to be discovered within the recesses of the human soul, where it makes direct contact with the cosmic soul. The discovery does not depend on meticulous observation of empirical phenomena and painstaking experiments to test theory against the findings of observation. Science in the sense in which it has developed in our culture is not impossible, but it is unnecessary. Consequently, in the great cultures of China, India, and Egypt, in spite of the brilliant intellectual powers they have manifested, science in the modern sense did not develop. And even Greece, which came closer than any other ancient culture to developing a viable science, failed to do so and relapsed into the ancient idea of a cyclical universe—the most pervasive form of belief in a world that is rational but not contingent. A developed science can, as we have seen in modern examples, peacefully exist within this kind of monistic world-view where the universe is seen as the necessary form of an immanent rationality; but such a world-view cannot, it seems, give birth to a spontaneously developing science. It can coexist with it but it cannot create it. The necessary precondition for the birth of science as we know it is, it would seem, the diffusion through society of the belief that the universe is both rational and contingent. Such a belief is the presupposition of modern science and cannot by any conceivable argument be a product of science. One has to ask: Upon what is this belief founded?
I hope that the relevance of this twofold excursion into the history of science will become clear as we proceed. The first point to be made is this: It is clear that what one may call the “methodological atheism” of modern science has been part of the clue to its dazzling success. It was and is part of the recognition of contingency in the nature of things. As long as scientific thought was controlled by the idea of perfect numbers and perfect circles, or by the concept of the purposeful organism (and both of these were legacies of Greek science)—in other words, as long as it was controlled by the idea of a completely immanent rationality—the breakthrough to modern science could not occur. It could only do so by virtue of a firm determination to study the phenomena and, so to speak, to allow them to speak for themselves. But by the same token, it is easy to see that a purely mechanistic vision of the ultimate nature of things is equally certain to become a fetter on the development of genuine science. And we have seen how the advances in physics during the present century have rendered implausible this mechanistic vision, and indeed any form of purely immanent rationality. Contemporary physics recognizes a finite and therefore contingent universe. It acknowledges limits beyond which its own axioms do not operate, and this again is a recognition of contingency. And in the Gödelian theorems, it recognizes that mathematics itself does not consist of absolute and eternally necessary truths but has in it an element of contingency.