The Relations of Science and Religion / The Morse Lecture, 1880

by Henry Calderwood

There are thus before us the chief results of physical science, as to the nature of matter, when we specify that it is indestructible, that it consists of ultimate molecules or atoms, and that its compressibility is to be explained by pressure upon such atoms, or cohesion, or comparative closeness of relation between them, this being greater in solids, less in liquids, and least in gases.

From the structure of matter, we are led by science to the consideration of energy, as distinct from matter. These two stand in some respect in contrast with each other. In taking a survey of the physical aspects of the world, we can not limit attention to the mere mass, or to questions bearing on its structure. Observation must now be turned on the perpetual change going on in form, arrangement, and distribution of materials. There is need for a science of all this, in accordance with which the perpetual round of change may be reduced to order by reference to causality and the laws of its operation. Thus we are introduced to our ordinary conceptions concerning position, that is, the situation or place of objects, or of masses of material, or even of worlds, to each other; motion, or change of position, modifying or altering the relations of objects; and force, that is the relative amount or proportion of energy at work for the accomplishment of such changes as those already mentioned. In these connections we are introduced to recently formulated doctrines of energy, reached in searching for "the cause which alters or tends to alter a body's natural state of rest," as this problem was indicated in Newton's first law of motion. In the earlier stages of inquiry, attention was directed mainly on the active forces of nature, as these are recognized in operation, admitting of calculation as to rate of movement on the one hand, and relative amount of force on the other. Computations of this kind were necessarily involved in research connected with the movements of the heavenly bodies. When astronomical theory had been matured and a truly scientific understanding of the solar system had been reached, physical science had next to deal with the more general problem raised by the contemplated forces of nature, having a reference at once wider and more minute. It is not possible here to do more than give a very summary view of the doctrine of energy, its mutations, dissipation, and conservation, as developed through study of the laws of gravitation, electricity, light, heat, etc., and now generally accepted. An outline will, however, suffice for an understanding of the general conclusions.

Energy is the term now employed to designate every form of power belonging to the physical world capable of doing work, and of being estimated according to the comparative amount of work it can perform. The whole phenomena of motion thus belong to this department of inquiry. The first distinction here has been described as the difference between energy of position and energy of motion.[AG] Both of these must be taken into account in order to have a full view of the facts. Energy of position, is illustrated by a water-head, or reservoir, where an accumulation of water is laid up in store, ready to be drawn upon for motive power when machinery set up in a position somewhat lower is to be brought into action and made to do the work for which it has been constructed. Energy of motion is seen when the storehouse of water is opened and the rush of the current sweeps along the prepared channel descending upon the great wheel, which sets in motion the whole machinery. In such a case as this, the amount of work done by the revolutions of the great wheel is an exact measure of the amount of water which has passed to a lower level. Or let us suppose there is only a limited supply in the water-head, and that there are no feeders, but that the streamlets and springs from which it is supplied, have ceased to flow, and let us suppose that the mill comes to a stand because of failure of motive power, the amount of work done up to that moment is the measure of the energy stored in the water-head before the sluice was opened. This illustration indicates the mode of calculation to be applied to energy in all its forms, including the great forces of nature, before which human power is as nothing. Taking thus the correlatives position and motion, we may regard the former as preparation for the latter, for, as Professor Balfour Stewart has said, "It is the fate of all kinds of energy of position to be ultimately converted into energy of motion."[AH] On this account, energy of motion most naturally exemplifies what we understand by energy; but on the other hand what has been called the energy of position must be regarded as a power distinctly calculable. If a stone be thrown into the air, the energy expended in propelling it to a certain height, is the exact measure of the energy expended in its descent. There is no need for entering here upon the calculations of the relation between energy and velocity, showing the exact proportion of the one to the other, or the ratio of increase according to velocity, which is expressed in the formula "that the energy varies as the square of the velocity," giving us an exact measure of force.

Aided by the conceptions of position and motion, we take the next step when we advance to transmutation or conversion of energy. What is made visible to us by motion is the transference of energy from one object or portion of matter to another. And this is the sole explanation of what occurs. There is no such thing known to physical science as the origin or creation of energy; all that is recognized is the disappearance of energy from one position and its appearance in another. If work has been done, energy was somewhere stored capable of doing it; a transmutation has taken place; and the work accomplished is the record of the process. In recognition of this, every machine is merely a more or less skilful contrivance for transmuting energy into a form more convenient or suitable for human purposes. The intelligence of man simply recognizes the law of transmutation, and deals with the problems which arise connected with the mechanical arrangements facilitating the process.

We next advance a further step, only to embrace another phase of the same truth,—the complement of what has been already stated,—that is, the conservation of energy. As we have seen, all that appears in motion, is transmutation or conversion of energy; accordingly it follows, that there is change of position, but no destruction of energy, or absolute disappearance of it from existence. This generalization is illustrated by a most attractive series of observations, introducing to a fuller knowledge of the laws of heat. The natural tendency of ordinary observation is to favor the opinion that when work has been done, energy is spent or lost. And this popular notion, which has a kind of accuracy, in so far as it is needful to make fresh draughts upon available resources, is favored by reference to the economy of our bodily existence constantly renewing its demand for fresh food supply. But this popular tendency is easily explained by the circumstance that ordinary observation makes much more account of the phenomena of motion, than of the development of heat as a direct consequence. The machinist can not, indeed, afford to make little of the consequences of friction; but the ordinary observer makes much more of mass, and complication of mechanical contrivance, and velocity of movement. From this he passes easily to the fabric, or other production, sent forth; and then he may occupy himself with calculations bearing on the expenditure for coals and labor, along with tear and wear of machinery. But scientific observation has concentrated much more on the evolution of heat, and out of this has come the completed theory of the laws of energy. In this way, it became matter of distinct calculation that friction and percussion convert energy into heat.

Along with these observations we have to remark upon an attendant conclusion, which has an important bearing on all speculation concerning the destiny of the universe. I refer to the fact that transmutation of energy involves a deterioration and dissipation of energy. As in the history of energy, improved position adds to the advantage for the doing of work, so transmutation tends to diminish the advantage or utility of the energy for human purposes. Thus the energy expended in working a machine gives return in a product of recognized value, but the energy spent in contending with friction generates heat which is of no practical value in respect of accomplished work. Or as the latter fact has been stated by Professor Balfour Stewart, friction proves "itself to be, not the destroyer of energy, but merely the converter of it into some less apparent, and perhaps less useful form."[AI] In this connection, scientific observation was directed upon the appearance of heat simultaneously with the disappearance of visible energy. Gradually the conception dawned upon scientific observers that heat is a form of motion, and this has found general acceptance, although it is impossible to give direct proof of the doctrine. The conclusion has been supported by all the experiments of Davis, Rumford, Joule, Colding, and Helmholtz. This conception having been launched as to the probable explanation of heat, it immediately found, in accordance with the analogies of scientific thought, a greatly extended circle of application. Light and sound came to be classified with heat, as only different forms of motion. It would involve too extended a range to include here a detailed account of these experiments, or to consider what is involved in dissipation of energy, as bearing upon a still wider aspect of the order of things in the universe. I must, therefore, be content with the reference just given to the conception of heat as a form of molecular motion; and in doing so may revert to the consideration already adduced, that this is another doctrine of scientific belief, of which there is a constant tendency to increase the number, as science widens the range of its inquiries and speculations.

The outstanding general results of science as to the nature of energy are now before us. All observations concerning motion only present to view transmutations of energy, all of them imply that there is no such thing as the origin of energy, and no such thing as its extinction. There is indeed a constant tendency towards the degradation of energy, and a constant equalizing process which may bring to an end the present order of things in the universe. But the leading scientific conception with which we have specially to deal is that expressed in the phrase, "Conservation of energy," which must be regarded as completing our view of inorganic existence along with the other doctrine of the indestructibility of matter. As Professor Tait has expressed it,—"The grand principle of conservation of energy, which asserts that no portion of energy can be put out of existence, and no amount of energy can be brought into existence by any process at our command, is simply a statement of the invariability of the quantity of energy in the universe,—a companion statement to that of the invariability of the quantity of matter."[AJ]

The position is now reached at which it becomes possible to combine the results of scientific research as to matter and energy into a harmonious unity, with which to test the view of the world recognized by religious thought. Religion as an intelligent and devotional acknowledgment of a Supreme Being, involves a very clear and definite conception concerning the origin of the universe and its continuance. What is thus implied will be best indicated by negative as well as positive statements, in some such form as the following. First, negatively, the world we inhabit does not carry within it any explanation of the origin of its own existence; that is to say, neither the materials existing, nor the forces operating, are sufficient to account for its origin; neither can it have had existence without beginning. In positive form, the universe can be accounted for only by that which transcends itself; the supernatural is the key to the natural; Nature is a creation to be attributed to an Intelligent First Cause.

Are science and religion here in harmony in the form and measure compatible in the circumstances? This qualified and guarded form of the question is obviously required, for religious thought does not profess to be scientific, or in any sense authoritative as to the phenomena of nature, that is, as to the facts which observation alone can ascertain, or as to the immediate causes by which these facts are to be explained. On the other hand, science is exclusively a knowledge of nature, consisting of methodized observations concerning distinct orders of facts, and rational inferences founded upon these. It can not in true sense be concerned with the supernatural, but can only present conclusions as to the order and processes of nature, which by subsequent and independent exercise of our intelligence may be contemplated in their relation to the conception of the supernatural, as Intelligent First Cause. This subsequent exercise of thought, whether critical or constructive, is more properly the task of philosophy, in prosecution of those reflective and speculative exercises, which, proceeding from scientific conclusions as accepted data, consider their intellectual value as contributing towards a theory of the universe. Scientific men will, of course, more or less readily pass over to take some share in such philosophic speculation; just as religious men, purely under the impulse of religious interests, will be more or less disposed to do, in proportion to the range of their intellectual life. What is here said is not intended as an argument for any restriction upon such speculation on the part either of scientific or of religious men, for such questions are common property, and the arguments bearing upon them are to be tested by all. But it is of some consequence, specially in the present unsettled and sensitive state of the public mind, that it be clearly recognized that science is not itself responsible for the thoughts of scientific men on these questions; and that religion is not responsible for the thoughts of religious men upon them. Science can not determine any thing as to a philosophy of the supernatural, any more than religion can determine any thing as to a science of nature. Whether we take the violent and even passionate antipathy to any acknowledgment of the supernatural which is found in the Essays of Clifford, or the profoundly reverential acknowledgment of the Deity in the writings and life of Faraday, science is to be credited with neither. And so in like manner, when we have violent denunciations of science professedly in the name of religion, or intelligent appreciation of its high value from accredited upholders of religious truth, religion itself is to be credited with neither the one nor the other. This is a matter which comes within the range of ordinary intelligence. It may indeed belong to philosophy to formulate and develop the arguments in strict harmony with the recognized laws of mind; but it belongs equally to all men to estimate the general sweep and range of acquired knowledge as to the structure and order of the universe, as bearing upon the more general conceptions to be rationally entertained regarding its government. With this branch of the subject, ordinary thought may readily deal without entanglement in technicalities.