SINCE THE MIDDLE of the nineteenth century and the years following the publication of the Origin of Species, popular interest has never been so stimulated as at the present time by the discoveries of natural science and the theories of natural scientists. It is clear, furthermore, that much of this widespread interest in science is occasioned now, as formerly, by the same reason. In the last century, when the early theories of organic evolution were put forward, it was at once felt that these might have most definite implications with regard to the truth of certain traditional interpretations of the Christian faith. Today, largely owing to the popularization of modern scientific theories by Sir Arthur Eddington and Sir James Jeans, it is again felt that scientific theories about our universe may once more make great contributions to our interpretations of the religious experience of mankind. No clearer evidence could be found of the "incurably religious" quality of human nature than this. Whenever scientific theory shows signs of affecting religious interpretations of life, then, as at no other time, popular attention turns toward scientific thought and with an interest not untinged with emotion.
In response to this renewed interest in the supposed implications of scientific thought for the interpretation of religious experience, there is appearing an ever increasing body of literature. Many scientists and research workers are indicating to us the lines along which, in the future, they believe philosophy and religion must develop, while our pulpits ring with announcements, often at second hand, of the marvelous discoveries of modern science. The impression is gaining ground that, in some way or other, science is now much more friendly toward religion than was the case twenty years ago, although the exact form in which this friendship will show itself is still far from clear, and the kind of religion toward which it will reach out is as yet but vaguely known. It is probably not inaccurate to sum up the popular opinion of the moment as follows. There will develop a religion of the future acceptable to scientific minds. This will almost certainly not be a religion of Catholic orthodoxy, but with liberal good will on both sides and certain necessary adjustments, more particularly on the side of traditional Christianity, the so-called "conflict between science and religion" may at last completely disappear.
It is, nevertheless, an undeniable fact that we still have within the world the great body of traditional Christian faith, carefully systematized and transmitted by the Catholic Church throughout twenty centuries of Christian experience. This is the faith which, in the minds of many millions, is synonymous with religion. At the same time, scientific investigations are providing us with an increasingly adequate description of the physical world within which, for a certain period, each human soul must live and act, must grow and mature. We are gaining a progressively deeper insight into the regular mode of behavior of this universe of time and space, which is the same universe within which the Incarnation and the other great historic events of the Christian revelation are believed to have taken place.
Before modifying or, perhaps, abandoning the historic Christian faith, one who still holds it will wish first to define, as precisely as may be, those exact portions of modern scientific theory and of traditional Catholic thought which impinge the one on the other, and second, to inquire whether in these areas of contact the scientific and religious aspects of human experience are, in fact, totally incompatible. Careful analysis may show that the disagreements between them are not at present so acute as we had at one time been led to believe.
To none of the comparatively straightforward questions which emerge from such an inquiry have sufficiently detailed and satisfactory answers been returned. Many scientists and theologians who have discussed the present relations of scientific and religious thought have attempted generalizations in too sweeping a manner. On the one hand we have a scientist like Sir James Jeans concluding that the mind of God functions like that of a pure mathematician. It may be said in passing that there is nothing surprising in this, since man is much given to making God in his own image and Sir James is himself a mathematician. Neither is there anything contrary to Christian orthodoxy, since within Omniscience there is undoubtedly room for a knowledge of the Theory of Functions and even of the Tensor Calculus. But such speculations are not in the least helpful in answering the questions which we now propose to ask, although they might conceivably assist us in the future if we had cast down the old God and were attempting to set up a new one in His place. We have not yet arrived at this point. And on the other hand Dean Inge, as a modernist theologian, assures us that "Science, now wholly emancipated, goes on its way, and gradually creates a mental atmosphere which excludes the whole world view of Catholicism." [Christian Ethics and Modern Problems, p. 189.] This statement may also be true, but the specific facts and difficulties which science has placed in the way of a Catholic world view are not yet precisely explained. The modernists call for new creeds which will be acceptable to the "modern mind" without formulating in detail those precise implications of the ancient Catholic creeds which, in their opinion, the scientific knowledge of today renders untenable.
There are certain fundamental truths of experience which for a Catholic Christian, we can scarcely doubt, must remain forever in the category of pure faith. For example, such truths are those of the existence of a personal God and of the reality of personal relationships established with God in prayer. Such, ultimately, are the historic facts of the Incarnation and of a personal God revealing Himself and redeeming us by means of an historic activity in time and space, because the wonderful stories recorded by the histories of the life of Jesus of Nazareth might be admitted as scientifically and conclusively proved without compelling us intellectually to draw from them the quite amazing inference which is the historical foundation of the Catholic faith. We must also place in the category of faith a belief like that which we hold in the existence of the human spirit as a free or, at least, a not completely determined agent, justly to be held responsible in the sight of God for all its personal decisions and the events in which these decisions result. And in this category belong almost certainly our interpretation of the Gospel record of the bodily Resurrection of Jesus and the corollary of this interpretation, the expectation of our own personal resurrection and immortality.
Within the category of science belong, first, the observed facts which emerge from a controlled experimental study of our universe; and second, the conclusions and abstract generalizations which, in the course of time, are based upon these observed facts. These generalizations, mathematically or otherwise formulated, are known as the "laws of nature." They enable us to set up what has been called the orderly causal framework of the world, and to predict the course of future events from observations of the causes operating in the past and present. In this category, then, we place truths both of directly experimental and of abstract knowledge. Here also we place certain highly speculative concepts, hypotheses concerning portions of reality not yet directly observed, tentative theories which serve to govern the course of future scientific experimentation. For example, science is concerned with discovering and observing those entities which enter into the structure of our physical universe, the stars and planets, the molecules and electrons and other fundamental foci of matter or energy. It is concerned with the formulations of mathematical laws according to which these entities move and interact with one another. It is concerned with the composition and mode of circulation of the blood of animals, and the supply of oxygen to the living body by means of breathing. In its historical aspects, science is concerned with descriptions of the mode of formation of our solar system and of the universe of which our system forms a part. It describes the history of the formation of our mountains and seas, attempting to account for their present states, and it traces the evolutionary processes which have produced the living beings which we find in the world today.
Now within the categories of both faith and science there have been and still are many intellectual difficulties which are peculiar to each category alone and toward the solution of which ideas which belong to the other category cannot make the slightest legitimate contribution.
For example, as we have just said, we place within the category of faith the idea of a human spirit endowed with what we call free-will and therefore justly held responsible for its moral decisions. But the human spirit appears also and in another sense determined, since we cannot imagine that the free activities of any individual human being can be able permanently to thwart the ultimate purposes of the omnipotent and perfectly moral God revealed in Christ. It is also intellectually difficult to reconcile the ideas of human freedom exercised, and responsibility incurred within the time processes of our present world, with God's omniscience, which must transcend the secular processes of the universe. There are no discovered facts or formulated theories within the scientific category which affect either favorably or unfavorably the solution of these types of metaphysical difficulties of which these are examples.
In an analogous manner, no received or developed facts of faith can be of use in the solution of difficulties which are specifically within the category of science. For example, the radiant energy which gives us the sensation of what we call light was thought by Newton to be transmitted by means of myriads of tiny material corpuscles, shot out in straight lines through space, like a hail of bullets. Fresnel later showed that the behavior of light could be explained by assuming it to consist of waves traveling through an imagined medium called the luminiferous ether, which was presumed to permeate all space. Each of these concepts has proved in some ways inadequate and in some ways very helpful for harmonizing many recent experimental results obtained from further investigations of the behavior of radiant energy. It would appear that they cannot both be true in the sense in which they were originally held respectively by Newton and Fresnel, but to a decision between the two concepts, or to a new theoretical synthesis which will harmonize the advantages of both, the facts within our category of faith remain remote and indifferent. Likewise, the period of time which has elapsed since the first human beings appeared on earth has been variously estimated from correspondingly various sets of data, from different evidences of fossil and artifact remains. This type of problem, also, is purely scientific and the data of faith have no bearing on the scientific conclusions of ethnologists.
In all the discussions of the relationships between scientific and religious thought nothing is more important than to keep the two categories of science and faith distinct and separate. The most bitter controversies of the past between scientists and theologians have resulted almost entirely from a confusion of these categories. In the days of Darwin, it was thought by both theologians and scientists that a theory of progressive organic evolution was in flat contradiction to descriptions of Creation found in the Old Testament, just as two centuries earlier the idea of Galileo Galilei that the earth moved round the sun was thought to contradict the statement in the Book of Joshua that "the sun stood still" to await the Children of Israel's leisure in their slaughter of the Amorites. Whether the Bible--by which in English-speaking countries was often meant the Authorized Version--spoke concerning religion, that is, as guiding us in our experiential relationships to God, or whether it appeared to teach us something concerning science, that is, about our experimental relationships to the physical universe, it was to be unquestioningly believed. The Bible, in both popular and much scholarly opinion, appeared as one literally infallible whole. Therefore, to doubt that the universe was created in six days of twenty-four hours each, or that the heavenly bodies on a famous occasion obeyed the command of Joshua, was at the same time to doubt the facts of the Incarnation and the Redemption of mankind. Among scientists of the mid-nineteenth century, the geologist Philip Gosse was so convinced that the biblical chronology and presumed date of Creation belonged in both the categories of faith and science, that he resolved an acute intellectual conflict in his own mind by supposing the age-old fossils of animals and plants, which he found in rocks, to have been put there by God, as it must appear to us in a rather wily manner, to test the strength of our religious faith.
By a slow and painful process we have rediscovered--rediscovered, because the early Fathers of the Church are in substantial agreement with our modern views--that the Bible is intended to teach us religious truths only. Properly interpreted, it is a sure guide for man's religious life, but it can safely be appealed to only in matters concerning man's relationships to a spiritual environment, relationships between human souls and God. The revelation of the Holy Spirit, which has been given us through the Bible and through the historic religious experience of the Catholic Church, has, we now see, never included any direct scientific information about the physical universe. Man's physical relationship to his natural environment is something which the same Holy Spirit evidently confides to slow processes of discovery dependent upon the cooperating activity of the human mind. We can scarcely imagine that our revealed religion can give us, either now or in the future, any detailed knowledge concerning the behavior of the natural physical universe.
On the other hand, it would perhaps be rash to prophesy that the time could never come when the truths which belong in the category of faith might be seen to follow logically and in their entirety out of the proved truths of experimental science. This time has certainly not yet arrived. It seems improbable that it ever will, although, for example, the psychical investigations of Sir Oliver Lodge and his co-workers indicate a direction in which such a development might conceivably appear. Up to the present these particular investigations have tended, in many minds, to accomplish little more than to confuse the data which are essentially those of faith with those of science, as two generations ago, when the Darwinian controversy began, the data which were essentially those of science were confused with those of faith.
What then should be our procedure in classifying and examining the very real problems and conflicts which have arisen and which may still arise between current scientific and traditional Catholic views of the universe in which we live? For this purpose, at the present stage of human thought, there is no more profitable method than to assume the truth of the whole body of traditional Christian faith as received and interpreted by the Catholic Church. In addition, let us also assume the truth of the authoritative and approved discoveries of experimental science and, insofar as these are adequate for the description of observed natural events, we may assume the correctness of scientific formulations of natural laws, based upon experimental discoveries. We may go further and assume, with some hazard, that present-day scientific hypotheses, on which further advances in natural sciences are being based, are tending in the direction of disclosing fuller truth than we now possess. We can profitably make all these wide assumptions for the sake of our investigation. In this present connection we should also take care not to confuse the issue by concerning ourselves with the highly metaphysical and other intellectual difficulties which, as we have already said, characterize certain items in both the separate categories of science and faith. Neither should we cause Science to say to Faith nor Faith to Science: "You are wrong and I am right." Without any emotional bias or any personal desire for the victory of one point of view over another, when they are found at variance, we should confine ourselves quite simply to an attempt at discovering whether the physical world as described by science and the spiritual world as described by the traditional Catholic faith are, in certain chosen aspects, compatible with each other or not.
It is within this relatively circumscribed field of investigation that certain difficulties have arisen in the past and do still arise. For although we have just been insisting on as careful a separation as possible between those facts and concepts which, for their fundamental data, their experimental evidence, their experiential background, or for their "proof" or "disproof" must be referred exclusively to the categories, on the one hand, of faith, and on the other, of science, this sharp division is not more than a practical one. The dichotomy is artificial and only for the sake of defining our problems. We must in no way imply that we lead a kind of double existence. About this we cannot be too emphatic. We do not suppose, in an extravagantly dualistic manner, that we experience simultaneously both a "natural" and a "supernatural" world. We do not live at one time in two self-contained and independent, albeit super-imposed universes, one "spiritual" and the other "material," which might at heart be qualitatively diverse and be governed by quite different kinds of principles. We must rather suppose, in the last analysis, that from both scientific and religious experience we abstract intellectual systems and concepts which apply to a single universe, even if much of this be beyond the reach of physical experimentation. The world of religion and of science is one "that is at unity in itself."
For this reason it is by no means permissible to take refuge in the "water-tight compartment" theory that scientific and religious presentations of truth have nothing whatever to do with one another and, in thought, must never be brought into juxtaposition. On the contrary, although these different presentations arise from different sets of data, which, in their own origin, must not be confused or mixed, it can easily be shown that in their developed forms they very obviously impinge on one another at many points. If in such cases some developed scientific and religious truths, which were formerly in conflict, are at present found to be compatible with one another, then some corresponding states of serious intellectual strain, which in the past have been felt by intelligent people who were prepared to accept both current scientific theory and traditional Catholic thought, may now be relieved. And if in some instances they are still found to be incompatible? We shall be very unwise if, on this ground alone, as has too often happened in the past in the case of rigid "fundamentalists," we characterize any scientific statement as completely false. We shall also be unwise if, as too often happens in the present in the case of eager "liberals,"we make ready lightly to understate or completely to abandon any essential element of our traditional faith. Rather, we can reserve our judgments, knowing that sound science is still content to labor patiently and that true faith, as Cardinal Newman has said, ought to be content to wait.
It is not possible in the compass of a short paper to give more than a brief example of one of the fundamental conflicts which have arisen in the past when the two descriptions of the world provided respectively by Catholic Christianity and by current science have impinged on each other. But with this one example can be indicated the way in which this and a number of like conflicts are at this time being resolved.
Probably the most deep-seated strain which appeared during the nineteenth century between Christianity and science was found in the conflict between freedom and determinism, between the ideas of free-will and responsibility and those of complete and mechanistic determination of the present and future by the events of the past. The Catholic faith insists that individual human choices of action and of thought are in some way free, that is, not completely tied down by the inexorable forces of the past. It insists that they are in some measure manifestations of new contributions from the will of the individual human being who makes these choices. A choice for which a human individual can justly be held responsible to God must contain elements arising solely and exclusively from that individual and which no amount of knowledge of the physical events of the past, even of physical events occurring in the subject's brain, would have enabled another person to predict. Such a choice, in other words, contains elements of unpredetermined "newness" appearing within this world of time and space.
Here is a characteristic of the world in which Catholics believe they live, which seems in sharp conflict with the description of that world which nineteenth century science provided. It was then widely believed that the world of time and space was a completely determined world, in the sense that the movements of a machine are completely determined from the moment that it is set in motion. The physical world, it appeared, had been set in motion in some unknown manner in the remote past, but once this had happened every succeeding event followed in a determined manner. The future was completely predictable from observations made in the past, or would become so as we gained sufficiently complete knowledge.
The man who believed in such a world could legitimately say to a Catholic: "You may have faith to believe that you are created a free agent, but unfortunately for yourself you have strayed into a determined world. Your freedom, therefore, is nothing but an academic notion. You are like a runner bound to a stake, who can never run. You may be potentially free, but in this world you cannot so act. You must wait for some other conditions of some other world before you can put your freedom into practice." Such a conflict might not arise in the mind of a strict Calvinist, who, believing in a rigid spiritual predestination, ought, it would seem, scarcely to object to living his life within a predetermined physical world. But to the Catholic a predetermined world presents great difficulties.
Because not only, as has just been said, must individual freedom of choice be exercised in such a world, which seems impossible, but those greatest of all historical events, the miracle of the Incarnation and the resulting marvels of the life, death, and resurrection of Christ, must have taken place within it. If our universe be more rigidly determined than any machine in a factory and just as little hospitable to any exceptional events, that is to any events which were not provided for when the machine was started, how can any deviation from so-called "normal behavior" be tolerated? How can any exceptions from so-called "natural laws," that is the rules of operation which we formulate from watching the machine run, be imagined? How can any element of physically unpredictable "newness" be introduced into the "givenness" of a world which is completely fixed in advance? Thirty years ago there seemed no intellectually satisfactory answers to these questions.
Today the situation has completely changed. Physical science no longer describes a world which is completely determined in advance, like a machine. The future behavior even of inanimate physical objects, it would seem, always contains a certain element of unpredictability. In the case of large objects, those which make up the world of our every-day experience, this uncertainty is so slight as to be quite negligible. The functionings of the world of ordinary events are still seen to be perfectly regular and reliable. Here, with a complete knowledge of the past, we can still predict the future with a practical exactness. But in the small-scale world, that of electrons and other small-scale entities, the unpredictability of the future becomes something to reckon with. Physical science has now set up a "Principle of Uncertainty" on which to base its own developing theories of the behavior of the physical world. And this same realization that the present and future always contain something new, which is by no means completely given by the past, is also appearing in modern theories of biological evolution. A "newness" is continually coming to light, it may be a truly purposive newness, from sources which, like the sources of the uncertain behavior of the electrons, may, as has been suggested by one eminent physicist, lie in a background of the universe forever inaccessible to experimental science.
Such considerations show that the conflict between freedom and the older scientific determinism has completely disappeared because physical determinism itself has been abandoned. This does not mean that the inanimate world is endowed with a "free-will" of its own. Neither does it mean that we have, even now, any "scientific proof" of the kind of freedom of the human will in which Catholics believe. As a matter of fact it does not even mean that one may not still hold that the spirit of man is as determined as a machine. A predestined spirit could live, one may suppose, within an unpredeter-mined world. But it does mean that one may no longer invoke scientific physics to support spiritual determinism. Spiritual determinism must now be held, if it be held at all, as much a matter of faith as is freedom. But if, as is the case with Catholics, freedom is acknowledged, it means that a human spirit can find itself at home in the physical world as this is at present described by science. The Catholic cannot now be told that he must wait for some other world to put his freedom into practice. Indeed, the world as it is described by modern science may, on investigation, turn out to be the best conceivable environment for the activity and growth of a morally creative human spirit, endowed with the power of freely and intelligently cooperating with God in the unfolding of His eternal purpose within the framework of our time and space.
The foregoing example illustrates the method in which Catholic thought should seek to measure itself against the scientific world views of this or any other age. Catholics should seek first of all to render as clearly and decisively as possible to the category of faith those things which are of Faith, and to the category of science those things which are of Science. Having done this, we should set out to see whether the religious and scientific views of the world, insofar as they overlap each other, are in agreement or in conflict. If at any time conflicts are seen to exist, we ought to bide our time quite calmly, even when this is a distinct intellectual strain, confident that with proper effort the mission harmony of the world will one day be disclosed. That has been the method of some of the greatest thinkers of the past, both religious and scientific. It should be ours today. At the present stage of our religious thought and of our scientific knowledge, we of this decade appear to have a particular advantage. Toward the end of the past century, the number of intellectual problems which, in the presence of current science, Catholic philosophers had to reserve for the future seemed overwhelmingly large. The prospect of their satisfactory solution also seemed discouragingly dim. In other words, it began to look as if faith demanded a world view which, for an indefinite period, experimental science might render intellectually untenable. Indeed, the intellectual strains thus set up brought many a religious philosopher to make concessions which are seen to be fatal to the Catholic position. Today, on the contrary, the whole posture of natural science is altered. We begin to see indications of a reality at the foundations of the universe disclosed by present-day science which, in its qualitative aspects, is almost startlingly concordant with the basic realities which are implied in the intuitive or, as we prefer to say, the Spirit-guided deliberations of the early Councils of the Church. We begin to see the kind of a physical and biological world in which the statements of the historic symbols of the Catholic faith can be intellectually at home.
This is not, let us repeat, saying that the scientific investigations of this time are "proving" the truth of Catholic Christianity. We should learn from the history of the Darwinian controversies that just as science did not then "disprove" any Catholic principle, so now we should not look for any analogous "proofs." "Proof" is not a proper word in this connection, because the foundations of faith lie deeper than any possible scientific knowledge. But we begin now to realize that the natural structure of the universe is little by little being disclosed as compatible with the supernatural structure of our faith. What, to a Catholic philosopher, is the most exalted goal of our purely intellectual endeavor begins to cast its light upon our path.