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Lecture 1. The Unfathomed Universe and the Aim of Science.

§ 1. Man's Early Outlook on Nature. § 2. Growing Recognition of a Scientific Order. § 3. Aims of Science. § 4. Limitations of Natural Knowledge. § 5. The Function of Feeling in our View of Nature. § 6. Towards a Philosophical Interpretation of Nature. § 7. Science and Religion.

§ 1. Man's Early Outlook on Nature.

IN early days men must have looked somewhat distractedly and uncomprehendingly on the crowded world without, discerning only glimpses of order amid the big booming confusion. There is a ring of truth in the fine description Æschylus gave, that—“first, beholding they beheld in vain, and, hearing, heard not, but like shapes in dreams, mixed all things wildly down the tedious time, nor knew to build a house against the sun with wicketed sides, nor any wood-work knew, but lived like silly ants, beneath the ground, in hollow caves unsunned. There came to them no steadfast sign of winter, nor of spring flower-perfumed, nor of summer full of fruit, but blindly and lawlessly they did all things.”

Poincaré speaks of the days before Man learned from the stars that there was a reign of law. “Isolated amidst a nature where everything was a mystery to him, terrified at each unexpected manifestation of incomprehensible forces, he was incapable of seeing in the conduct of the universe anything but caprice” (1913, p. 290). So large were the seas of ignorance, so many the straits, that there was as yet no discernment of the coherent continents of knowledge.

Gradually, however, Man came to himself and grew in knowledge of the empirical order of Nature. It was a great step when he first recognised the year with its object-lesson of recurrent sequences—a basis from which to observe other practically important uniformities. What a momentous beginning the Chaldæans made who first discerned that the multitude of the stars was “not a confused crowd wandering at random, but rather a disciplined army”! It was a working knowledge of natural processes, rather than an understanding of them, that was in the first instance built up, and it was correlated, on the one hand, with a still very imperfect mastery of the forces of Nature, and, on the other, with a belief in magic and in the possession of things by spirits—imaginative constructions which are perhaps analogous, as Prof. W. E. Ritter suggests, to the materialism and animism of later days.

§ 2. Growing Recognition of a Scientific Order.

The empirical order was gradually replaced by a scientific order. Some practical need pressed a question home; imagination found a clue; measurement or some other form of accurate registration furnished reliable data; a regularity of sequence was discovered and tested; a law was formulated. Especially after the foundation-laying work of Galileo, did the scientific reconstruction of the physical world proceed apace. There was a period of the discovery of the ‘Forces of Nature’ and of the ‘Laws of Nature’, and a growing clearness. “God said, Let Newton be, and there was light.”

The scientific order has grown like an organism. Its methods have become more penetrating; improvements in instruments (such as telescope and microscope, spectroscope and radioscope) have almost meant new senses. Its standard of accuracy has been raised, many residual phenomena and minute discrepancies, previously neglected, have pointed the way to discoveries, as in the case of Argon. Its concepts have been periodically thrown into the crucible of criticism, and come out clearer, or not at all. Thus force, instead of being a power inherent in substances, became a measure of the rate of transference of energy, and heat became a mode of motion. Large bodies of facts which used to be regarded as beyond science, the weather and dreams for instance, have become amenable to scientific treatment.

The progress of science wrought inevitable changes in man's outlook. The work of Copernicus and Galileo shattered the geocentric theory, which made our Earth the centre of the solar system, and subsequent discoveries showed what a small corner of the universe our whole system occupies. Not that we estimate man's kingdom in furlongs! The great discoverers in astronomy, physics, and chemistry revealed more and more clearly the reign of law in the inorganic world. No room was left for guidance or control other than, there is in the nature of things themselves; no room was left for interventions or influxes; and the idea that physical events were immediately ordered “by the hand of God” in relation to human interests disappeared like a dream. There came indeed to be an exaggeration of the omnipotence of the Laws of Nature—man's formulations of observed uniformities of sequence, which, although they evidently approximate to reality, cannot be invested with absolutism. Yet the old order changed, giving place to a new—the whole inorganic world was more and more completely and consistently analysed in terms of dynamics.

In regard to the realm of organisms also the outlook changed. The filiations of living creatures were discovered and the special creationists retreated before the evolutionists. It was shown that the living body is the theatre of many chemical and physical operations in a line with those of the inorganic domain. The chains of physiological events that make up everyday functions and behaviour were disclosed. Plants and animals were brought under the reign of law. The fitnesses or adaptations which seemed to speak so eloquently of a direct Designer were shown to be the outcome of long-continued processes of varying and sifting. And when Man's zoological place in Nature was recognised, the anthropocentric theory saw the beginning of its end. Even for those who continue to maintain, rightly we think, that organism is more than mechanism, that organic evolution is not a mechanical process, that thinking, feeling, and willing are activities that count, that man transcends his ancestry, and that it is not only legitimate but necessary to regard the cosmic process in the light of its outcome—the whole aspect of the world has changed.

But experience is the only limit to the application of scientific methods, and a new psychology began to accompany the new physiology, rather at the risk of its own life, to be sure, because of its partner's appetite. The outlook was changed by the disclosure of the close interdependence of what is conveniently called ‘mind’ and what is conveniently called ‘body’, by increased knowledge of the individual development and racial evolution of mental powers or modes of behaviour, by a disclosure of a certain amount of common ground between man and beast, by an analysis of obligatory modes of activity which we call reflexes and tropisms, and so on. Thus science has extended its claims.

With the advance of natural knowledge—at times very slowly, and again by leaps and bounds—has come an increased control of Nature which is as rich in promise as in achievement. We have recalled the picture Æschylus gave of our ancestors—living in caves, fearful of wild beasts, often dying of hunger or of poison, without wood-work or metals, without fire, without foresight, and unable to think of the general well-being. What a contrast between that picture and our life to-day. For nowadays the serpent that bites Man's heel is in nine cases out of ten microscopic; year by year Man increases his mastery over the physical forces; he coins wealth out of the thin air; he annihilates distance with his shrewd devices; he makes the ether carry his messages; he is extending his rule to the heavens; and he is making experiments on the control of life itself. In the so-called purely physical domain, at least, his dreams have more than come true.

After a long period during which science consisted of numerous discrete bodies of knowledge, largely related to the practical control of Nature, there began to be concentration into a system, a sort of cosmology. Science entered upon a new and purely theoretical rôle of giving man a composite picture of the world and its processes. This is increasingly impressive, the more we realise it—which means hard work. After a long ascent we get a new view, æsthetically magnificent, intellectually a revelation of connectedness. But, fine as it is, the scientific picture has satisfied very few thinkers of distinction, the chief reason being that the contributions which each science makes are always partial views, reached by processes of abstraction, by focussing attention on certain aspects of things. Pooling the results of the several sciences does not of itself result even in a scientific system, for that requires correlation. Still less does it result in a philosophic system. This will be clearer if the aims of science are discriminated.

§ 3. Aims of Science.

Science expresses a quite specific endeavour to get phenomena under intellectual control, so that we can think of them economically and clearly in relation to the rest of our science, and so that we can use them as a basis for secure prediction and effective action. Knowledge is foresight, and foresight is power. The direct motives of science are, in the main, intellectual curiosity, a self-preservative dislike of obscurities, a desire for unity and continuity in outlook. Often, in particular cases, the immediate motive may have been utilitarian—a desire for mastery; but the great majority of important practical discoveries have behind them a long labour of theoretical research pursued for its own sake.

That the chief end of science is descriptive formulation has probably been clear to keen analytic minds since the time of Galileo, especially to the great discoverers in astronomy, mechanics, and dynamics. But as a definitely stated conception, corrective of misunderstandings, the view of science as essentially descriptive began to make itself felt about the beginning of the last quarter of the nineteenth century, and may be associated with the names of Kirchhoff and Mach. It was in 1876 that Kirchhoff defined the task of mechanics as that of “describing completely and in the simplest manner the motions which take place in Nature”. Widening this a little, we may say that the aim of science is to describe natural phenomena and occurrences as exactly as possible, as simply as possible, as completely as possible, as consistently as possible, and always in terms which are communicable and verifiable. This is a very different rôle from that of solving the riddles of the universe, and it is well expressed in what Newton said in regard to the law of gravitation. “So far I have accounted for the phenomena presented to us by the heavens and the sea by means of the force of gravity, but I have as yet assigned no cause to this gravity.…I have not been able to deduce from phenomena the raison d'être of the properties of gravity and I have not set up hypotheses” (Newton, Philosophiœ naturalis Principia Mathematica. 1687).

“We must confess,” said Prof. J. H. Poynting (1900, p. 616), “that physical laws have greatly fallen off in dignity. No long time ago they were quite commonly described as the Fixed Laws of Nature, and were supposed sufficient in themselves to govern the universe. Now we can only assign to them the humble rank of mere descriptions, often erroneous, of similarities which we believe we have observed.…A law of nature explains nothing, it has no governing power, it is but a descriptive formula which the careless have sometimes personified.” It used to be said that “the laws of Nature are the thoughts of God”; now we say that they are the investigator's formulæ summing up regularities of recurrence.

This view of the function of science must he accepted as expressing at least part of the truth, for who should know better what they are aiming at than the great discoverers themselves? But is it not necessary to make certain reservations? (a) First, instead of explaining an event by showing that it obeys a law of Nature, the modern investigator is content to say that it is fully described or represented in such and such a formula, that it can be included in this or that typical case. As Aristotle said, from a great number of experiences one general conception is formed which will embrace all similar cases. There is unification under a common law. As Clifford says, “A true explanation refers the previously unknown to the known.” It assimilates the less known to the better known. But we must not overlook the preliminary analysis and reduction to a common denominator which made it possible to bring an apparent incommensurable into a series, and to recognise unity and continuity of process. Equations may not be explanations, but the analytic descriptions given by exact science are very different from the pictorial descriptions of everyday life. There is sometimes a mock modesty in the declaration of the scientific inquirer that he is describing not explaining; and there is deceptiveness in his formulation, if he reaches his simplification by violence, by a jugglery which coerces to a common denominator such fractions of reality as motion and emotion which are radically incommensurable.

(b) Second, there are laws of Nature such as Gravitation, which sum up uniformities in terms largely independent of hypothetical constructions. These must be distinguished from summations in terms of what Rankine called “conceptions of a conjectural order” which image the intimate nature of things and processes. Ohm's laws remain, whatever be our view of electrical energy. Mendel's law remains, whatever be our views as to what are called ‘factors’ in inheritance. As long as we consider moving bodies in bulk within sensible distances of the earth, the law of gravitation holds absolutely, and states without hypothesis how the motions of the bodies and the earth are mutually affected. But if we proceed, with Le Sage or some other, to a theory of gravitation, we enter a realm of imaginative construction. We work with concepts which are, no doubt, ingenious, well-thought-out, consistent, and useful; but how far they correspond to, or are representative of objective entities is a question to be carefully considered. Sometimes the concepts that are effectively worked with are obviously mere symbols; thus no one supposes that carbon atoms are really like their quite useful quadrumanous diagrammatic representations in books on chemistry. The difficulty is in regard to subtler symbols or concepts, which work so well that we inevitably come to think of them as objective actualities. And it may be that what was at first an imaginative thought-economising symbol, part of a system of intellectual shorthand, will be actually verified in Nature. Thus many physicists now speak confidently and convincingly of the ‘reality’ of the atom. When it is legitimate to speak of a scientific symbol as real is a matter for the experts only, as is plain enough from their disagreement. Thus the ether was declared by Lord Kelvin to be the greatest certainty in. physics, while we find the upholders of the Principle of Relativity declaring that the Victorian ether and the Victorian matter must both go. Similarly in biological problems, such as those centred in inheritance, there is divergence of opinion as to the objectivity of ‘biophores’, ‘determinants’, ‘factors’, and ‘genes’, though these are very useful in formulating conclusions and prompting further questions.

(c) Third, it has to be remembered that the descriptive formulæ are more than summations of the routine of individual experience (a view which would lead us near the impasse of solipsism), for they are verifiable by all normally constituted minds, and that they must have a close correspondence with the actualities of Nature since the predictions based on them are fulfilled. We continually risk our lives on the closeness of this correspondence. That we are not betrayed proves, not that the concepts or intellectual counters used in representation are like the real things, or are even the only usable concepts, but that the uniformities which the concepts are used to detect and to represent are real.

Speaking of the electrical theory of matter, the late Prof. J. H. Poynting said: “The chief value of such hypothesis lies, not in its objective truth, but in its success in accounting for, in co-ordinating, what we actually observe, and in predicting results which are afterwards verified. It is to be regarded as a ‘working model’ which gives the same results as the actual atom, though, it may be, by quite different machinery.” While adhering to this view, let us, however, safeguard it by recognising that the validity of the working model depends on its verifiability, and on its correspondence with actualities. As Hertz said, the quality of scientific symbols is such that their intellectually necessary consequences correspond to occurrences. For certain purposes the view that the sun goes round the earth is just as effective as the conclusion that the earth goes round the sun. We can rise at dawn with equal punctuality on either hypothesis. But beyond a short radius the former will lead us hopelessly wrong, while the latter never will.

(d) Fourthly, it is interesting to notice that Bacon did not include historia naturalis in his encyclopædia of the sciences, probably because it remained too concretely descriptive and did not admit of formulation in terms of abstract concepts, as astronomy, for instance, does. Yet there is in natural history a kind of description which is just as essential in its own place as is mechanical or dynamical description—namely, historical description. We would not buy a horse on the strength of a description in terms of the dynamics of particles, partly because we could not go far in the way of checking its accuracy, but mainly because of our shrewd conviction that the essential thing is to know what we can about the horse's history. Similarly, our science of the horse must include not only its whole architecture from skull to blood crystals, not only the consensus of its active parts from brain to phagocytes, but also its character and its individual and racial becoming. Even within the sciences of the inorganic, when dealing, for instance, with the geological interpretation of scenery or the establishment of the solar system, the description must be genetic or historical. It is an interesting point that, just about the time when Physics began to proclaim emphatically that its office was to describe not to explain, Natural History in Darwin's hands passed emphatically from description to historical explanation.

§ 4. Limitations of Natural Knowledge.

Science makes so many permanent discoveries, which are never contradicted though often transcended, that she acquires an assured confidence which has only been equalled by that of Theology. For this very reason it is useful that she should be ever examining herself. One of the famous balance-sheets was that made by Du Bois-Reymond in his lectures on the Seven Riddles of the Universe and on the Limits of Natural Knowledge. He confessed that the science of his day could not offer any explanation of the origin of life, the apparent purposivencss of Nature, and the origin of language; but he did not hold that these enigmas were insoluble. On the other hand, as to the essence of matter and energy, the origin of motion, the fact of sensation, and the freedom of the will, his pronouncement was not only Ignoramus, but Ignorabimus. Similarly to-day without ceasing for a moment to admire the splendour of scientific achievement, and the promise that there is of further conquests, we have to say many times Ignoramus, and perhaps it is no bad sign of the wholesomeness of modern science that it is acutely aware of its limitations—both intrinsic and extrinsic.

(a) To begin with, there is less forgetfulness of the fact that we know Nature only as it is mirrored in our minds. When we think of what science would have been if the stars had been always hidden in cloud, we realise that much has depended on the stimuli of the outer world; but the discernment of the cosmos has been within us, growing with our strength and hindered by our limitations. It is a familiar experience, for instance, that our immediate perceptual power increases at compound interest, the eye perceiving more and more as the mind is educated. Our concepts stimulate our perceptual powers to a higher degree of intensity.

(b) A large part of even the near at hand world is invisible, like the air. Much may escape all our senses, as the ultra-violet rays, which the ants feel, escape our eyes. It is said that there are living creatures, the Chlamydozoa, which lie just on the border-line of microscopic visibility; and beyond these minima sensibilia there may be organisms still smaller. An alien observer of the earth in early days might have complained of its azoic dullness, while the primitive Biococci were proliferating in billions beneath his feet. So to-day there may be forms of life and modes of energy around us which we do not know.

In any case, how different our world is from that of the man born blind; and what, asks John Burroughs, if we could go on opening one eye after another to the number of a dozen or so, and were able, he should have added, to correlate our impressions? What if we had three or more extra senses? How different our view of Animate Nature would have been if the microscope and the spectroscope, to name only two of our extraneous sense-organs, had not been invented! Apart from such imaginings we have many remarkable facts in regard to the cultivation of the senses that we have. The blind man knows every footstep in the village. In the opinion of some experts, there are considerable tracts of fallow ground in our brains, which may one day be tilled. How slow should Man be in supposing that he has exhausted a subject! There are few who have even a calculus which will show them how far they have succeeded in discerning the more or less obvious inter-relations or ‘aspects’ of the object of their study. Warned by such errors as that of Comte, who declared that Man could never know anything as to the chemical composition of the heavenly bodies, we have learned to be cautious in not putting in ‘full stops’. There is a large library now on the animals of the Deep Sea, yet it is not very long since a great naturalist declared that of the possible tenants of the Oceanic Abysses we could not hope to know anything unless some of them—if there were any—happened to tumble upwards to the superficial zones of reduced pressure. Science has reason to beware of saying “Non possumus”.

Yet, as a warning against finality in another direction, we must admit the vagueness that is apt to invest our knowledge of the past. In the perfectly exact sciences, we can sometimes work backwards with remarkable certainty to comets, eclipses, and the like; but in Biology how watchful we have to be lest we get entangled in the vicious circle of inventing a past from its continued life in the present, and then interpreting the present in terms of our invention.

(c) A reasonable humility of mind is also engendered by recognising how limited, after all, is our range of exact data. The late Professor Rowland, a distinguished physicist, writes (1899, p. 408): “In time we are limited by a few hundred or possibly thousand years.…In space we have exact knowledge limited to portions of our earth's surface and a mile or so below the surface, together with what little we can learn from looking through powerful telescopes into the space beyond. In temperature our knowledge extends from near the absolute zero to that of the sun, but exact knowledge is far more limited. In pressures we go from the Crookes vacuum, still containing myriads of flying atoms, to pressures limited by the strength of steel, but still very minute compared with the pressures at the centre of the earth and sun, where the hardest steel would flow like the most limpid water. In velocities we are limited to a few miles per second. In forces to possibly one hundred tons to the square inch. In mechanical rotations to a few hundred times a second.” Perhaps some of these limits have been extended since Professor Rowland gave the address from which we have quoted, but that would not affect our point,—the importance of bearing in mind the limits of exact knowledge.

(d) Another limitation is involved in the very nature of scientific procedure, which makes headway by abstraction. Divide et impera is the scientific rule. The scientific description of Nature is made up of many partial views contributed by the several sciences. We have to confine our attention at a given time to certain aspects of a thing or process. We treat of the mass of a body as if we had the body under the influence of gravitation only, though we know that we cannot secure the entire absence of electrical, magnetic, and other forces. Science works with perfect levers, with pure masses, ‘ideal systems’ in general—which we do not meet in everyday life.

In certain cases the abstracting is obvious and not dangerous; in other cases it escapes attention and leads to fallacy. We know that biologically we cannot abstract the trout from the stream; even for the purposes of analytical anatomy we must remember the environment, still more when dynamical relations are considered. This is obvious, but is it so obvious that a theory of animal behaviour which reduces all to ‘forced movements’ or tropisms is the outcome of “a process of abstraction which leaves out the characteristic features of the concrete fact to be explained”, the plasticity, the endeavour, the awareness of the organism?

(e) When we take the long and wide philosophical view of a subject, trying to see the phenomena or the process as a whole, the inevitable limitations of science must be borne in mind. If all Animate Nature is the outcome of a few Protists, we must see these in the light of the evolution as a whole. “The true nature of the antecedents, that is to say, of the apparent cause, is revealed only in the effects” (Pringle-Pattison, 1917, p. 332); or should one not say the full nature? If we believe that Tyndall's “matter” (British Association Address, Belfast, 1874), with its famous “promise and potency of all terrestrial life”, is exhaustively described in terms of the dynamics of particles, then we cannot by any ingenuity evolve the conscious out of it; if on general grounds we feel bound to regard conscious life as evolved from Tyndall's “matter”, then the reality of that “matter” could not be exhaustively described in terms of the dynamics of particles.

“All explanation of the higher by the lower is philosophically a hysteron-proteron. The antecedents assigned are not the causes of the consequents, for by antecedents the naturalistic theories mean the antecedents in abstraction from their consequents—the antecedents taken as they appear in themselves, or as we might suppose them to be if no such consequents had ever issued from them. So conceived, however, the antecedents (matter and energy, for example) have no real existence—they are mere entia rationis, abstract aspects of the concrete fact which we call the universe” (Pringle-Pattison, Man's Place in the Cosmos, pp. 11–12).

(f) The aim of science is not so much “to give an account of the whole matter”, as used to be said, but rather to work out, patiently and piecemeal, a number of descriptions and formulations of diverse aspects, each for a certain purpose, by certain methods, in certain symbols. The chemist's account of a peacock's tail is an abstraction, and so is the physicist's, the biologist's, and the psychologist's. But even when all these results, reached by scientific abstraction, are pooled, we have not “an account of the whole matter”—of “the positive full-orbed reality”. That correlation often has to wait for genius. Moreover, the scientific synthesis, if it be achieved, requires to be assimilated with what the artist, the poet, and the genuine lover of birds may be able to tell us concerning the peacock's tail. Huxley's declaration that the advance of science is synonymous with description in materialistic symbols, assumed too readily that formulations which give Man a considerable power of prediction and a considerable degree of practical control are therefore theoretically exhaustive.

(g) But let us consider further limitations. We describe what goes on around us or within us in the simplest possible terms, but the fundamental concepts we use are notably in process of development. As Kirchhoff said, “It la thinkable that a description which to-day is the simplest that can be given may in the further development of science be replaced by one still more simple.” It is also thinkable, we may add, that some of our present-day formulations will turn out to be too simple, for abstraction often leads to fallacy. This at least is certain, that when we describe occurrences in terms of matter and energy, life and mind, or any similar grand concepts, we are working with what cannot be called self-explanatory. Every one of them is big with mystery, though some are in process of simplification. Much so-called ‘explanation’ is reducing unusual unintelligibility to order rather than to radical understanding. No achievement in science has been more satisfactory than the Law of Gravitation, but can any one tell what actually happens in the unseen, universe when, the apple falls in the orchard? In language which is a survival we still speak of the force of gravity, the force of attraction, and so on, but we know that forces as causes do not exist. The earth does not pull the stone, the stone gravitates to the earth. Some have proposed to speak of bodies ‘tractating’ and ‘pellating’ instead of saying that they attract or repel one another. But, as Professor Soddy says, “Why two bodies tractate or pellate is not known in a single instance, least of all perhaps in the oldest recognised case, gravitation” (Matter and Energy, pp. 111–12).

We know of over eighty elements and much about many of them, but do we know what being an element, like Mercury or Antimony, really means, or the import of their periodic classification? Great libraries are filled with our descriptions of the structure and activities of plants and animals, but do we know what livingness essentially is? We cannot define it at present in terms of anything else, we take it as ‘given’. We cannot tell wherein consists the essential difference between the flight of a bird and the movement of a comet. How much, relatively speaking, is known of ‘mind’ and ‘body’, how little is known in regard to the relation between them, if there is a relation!

(h) We hear much of the achievements of science in tracing things back to their beginnings. That is the historical or genetic method, and it yields very interesting results. The present becomes more intelligible in the light of the past. But, when we get far back, how mysterious the beginnings become. How mysterious still, to tell the truth, are many of the big steps between the beginning and the end! In the inorganic sphere one collocation passes into another, usually without jolts. The course runs smoothly. But when we pass to organic evolution or even to individual development, we are almost driven back to a belief in magic! Who can tell even in the sketchiest fashion how a Silver Wyandotte was evolved from an Indian Jungle Fowl, or how stage gives rise to stage as the chick develops in three weeks from a minute transparent spot on the top of the yolk of an egg?

Matter has seemed to many easy-going minds a firm basis to start from, but what is matter, and what has been its history? Must there not have been a differentiation of various forms of matter, may there not have been a pre-material state of things, do we ever get to beginnings? This necessary limitation is well stated by Dr. Arthur Shipley:—“No body of scientific doctrine succeeds in describing in terms of laws of succession more than some limited set of stages of a natural process; the whole process—if, indeed, it can be regarded as a whole—must for ever be beyond the reach of scientific grasp. The earliest stage to which science has succeeded in tracing back any part of a sequence of phenomena itself constitutes a new problem for science, and that without end. There is always an earlier stage and to an earliest we can never attain. The questions of origins concern the theologian, the metaphysician, perhaps the poet” (Schuster and Shipley, 1917, p. 276).

(i) Another limitation has to do with causal sequences. In ordinary scientific discourse, as Bergson points out, three different meanings of the term ‘cause’ are common. A cause may act by impelling (one billiard ball striking another), or by releasing (a spark exploding the gunpowder), or by unwinding (the relaxing of the spring turning the cylinder of a gramophone and having the melody as effect). Now “only in the first case, really, does cause explain effect; in the others the effect is more or less given in advance, and the antecedent invoked is—in different degrees, of course—its occasion rather than its cause” (Creative Evolution, English Trans., p. 77).

In the domain of mechanics, in Gravitational Astronomy, we see the high-water mark of scientific description, in exactness and approximate completeness. There, with a clear intellectual conscience, we can proclaim, “causa æquat effectum”; for why, the resultant is just another form of the components. In the great majority of cases, however, where there is a qualitative change, we know that a given collocation of matter and energy gives rise to another, and does so uniformly, but we cannot tell why the resultant must be as it is and not otherwise. In the great majority of cases all that science can say is, “If this, then that”; and it is a very useful thing to be able to say.

Every one knows that oxygen and hydrogen will unite violently to form water, but all that we can say is that it is their nature to. Perhaps it may be explained as due to “the interplay between electricity and matter”, and then we shall shift the pegs of our claim in the desert of ignorance.

We rub our eyes and say: “But surely it is the very business of Science to show how things happen, to explain occurrences.” So in a sense it is, but as Professor Stout puts it, “What is really done is to show that a given result, often called an effect, is part of a continuous process which includes a known antecedent, often called the cause.” Indeed, “the current scientific conception of a cause” is the “totality of the conditions in the presence of which an event occurs and in the absence of any member of which it does not occur” (Taylor, 1909, p. 170).

(j) Finally there is a sense in which science, if not asymptotic, is bound for a long time to remain approximate. The Universe is still unfathomed.

(1) A scientific law formulates an observed routine in the order of nature, but sometimes it is only a provisional ‘fit’. Residual phenomena emerge which lead to restatement. So Kepler improves on Copernicus, and Newton on Kepler.

(2) Even when the ‘fit’ of the formulation is more than approximate, extension or intensification of inquiry may show that it does not apply beyond certain limits. Thus the law of gravitation, which must be very near to perfect accuracy when applied to planetary distances, may not hold either for very minute molecular distances or for immense stellar distances.

(3) Even generalisations that work well and must bear a close correspondence to reality, since they afford a basis for effective prophecy, may require some modification, in their setting at least, in the light of some new fact or idea, of great magnitude. Thus Prof. Frederick Soddy writes: “It sounds incredible, but nevertheless it is true, that science up to the close of the nineteenth century had no suspicion even of the existence of the original sources of natural energy.…The vista which has been opened up by these new discoveries [of the radio-active properties of some substances] is without parallel in the whole history of science” (Harper's Magazine, December, 1909, p. 53).

(4) We cannot pass over the caution suggested by the Michelson-Morley experiment, which showed that scientific observations cannot transcend the system in which they are immersed. In Prof. Wildon Carr's words, “It showed us that observers within a system of reference, in uniform movement of translation relatively to other systems, have no absolute standard by which they can determine their movement. There is no absolute ether, no absolute space, and no absolute time, by reference to which we can determine our movements” (1918, p. 21). And Prof. Max Planck writes of this new idea of the relativity of time: “With the revolution which it brings about in our conception of the physical universe, no other is comparable, in range and profundity, except that due to the introduction of the Copernican Astronomy.”

(5) Finally, it may be useful to remember that, according to current and probably well-warranted scientific belief, there was once a time when what happened upon the earth might have been formulated in its immediacy with apparent exhaustiveness in terms of the dynamics of particles. But that cannot be said now. New aspects of reality have in the course of ages ‘welled up’ and required new sciences. We know, too, as we say, the ends of processes which in azoic days had only begun. And yet we are not sure that we know any ends. (In the sense of goals), for the process continues. Science seems bound to be not only approximate but asymptotic, for its subject-matter continues to evolve.

One may have a more or less wholesome dislike of perpetual-motion mongers and their successors, but one resents scientific absolutism which will consider nothing that seems to infringe a law. For these laws, beyond those of mathematics, are not more than summations of experience in a certain limited here and now. The Uniformity of Nature which the legalists hold over us as a sacrosanct principle is a big assumption. For who shall define its tenure in a world of æonie flux?

We should remember, too, how thickly beset we are with unsolved problems of a less ultimate nature. What, for instance, is the commonest and most universal vital event? It Is cell-division. And though the literature about it would fill a large library, we do not yet know the conditions of its occurrence or the forces at work in its accomplishment! When we succeed in stating a problem in a clear way it is gratuitous to speak of it as insoluble, but of the number of unsolved problems and of the way in which the solution of one raises another, every one is aware.

For the reasons we have indicated in this discussion and for others, there are many, in this age of extraordinarily rapid scientific discovery, who stand wondering before an unfathomed universe. We have made many charts, but there is still more sea. Perhaps one of the most hopeful signs at once of the progressiveness of science and of its conformability with the humanities and philosophies is in its vivid realisation of its own limitations.

From the absence of a scientific answer to a scientific question, we do not dream of arguing, as has been often argued, that some other kind of answer, say theological, must be true. We have to render to Cæsar the things that are Cæsar's; and there is no exchange between scientific and transcendental coinage. But what we may usefully recognise is the self-imposed limitation of science, that it seeks, for certain purposes and by certain methods, to describe occurrences and processes in the simplest possible, universally verifiable terms, and that it does not pretend to exhaust their reality. This leads us to recognise the validity of feeling in an interpretation of Nature.

§ 5. The Function of Feeling in our View of Nature.

The world without has played a great part in the education of the human spirit. Its enigmas have quickened Man's intelligence; its practical problems have trained his will; Animate Nature in particular has been a school of feeling; the mother's face has been a factor in the evolution of personality (see Merz, 1916). In her manifold opportunities Nature has thus helped man to polish the mirror of his mind, and the process continues. Nature still supplies us with abundance of brain-stretching theoretical puzzles and we eagerly tackle them; there are more worlds to conquer and we do not let the sword sleep in our hand; but how does it stand with feeling? Nature is beautiful, gladdening, awesome, mysterious, wonderful, as ever, but do we feel it as our forefathers did?

What is this feeling for Nature? It may be a simple restfulness, such as Darwin once spoke of when for the moment he laid aside his questionings; it may be a keen æsthetic joy; it may be the thrill of a starry night; it may be the pleasure of seeing trust and affection in a dog's eyes; it may be the response our heart makes in spring when we hear the wild geese passing overhead on their northward migration, and know that another winter is over and gone; it may be that deep calls to deep, and we have a vicarious share in life's triumph over matter; it has often expressed itself in reverent worship; it may be an awed elation in finding ourselves part of so sublime a process as cosmic evolution. This element of feeling in our outlook on Nature is a satisfaction in itself, but our plea for allowing it to operate in our interpretation of Nature is that we get closer to some things through feeling than we do through science. Just as feeling contributes to our total appreciation of people, so of Nature. Through feeling we discern what science cannot get into focus. Not that any one dreams of mingling feeling with science or of attempting to eke out science with feeling, but to try to exclude feeling from our total view of Nature is to try to close one of the right-of-way paths to reality. Goethe went the length of saying: “Sympathy and enjoyment in what we see is in fact the only reality, and, from such reality, reality as a natural product follows. All else is vanity.”

In the preface to his Diversions of a Naturalist (1915, p. vi) Sir Ray Lankester, who has so greatly enriched Zoology speaks in a very interesting way of the value of science in giving us prevision and control, but goes on to say: “Science commends itself to us as does Honesty and as does great Art and all fine thought and deed—not as a policy yielding material profits, hut because it satisfies man's soul.” This is very different from the old moan that increase of knowledge is increase of sorrow, and surely more wholesome, but we wonder if it is true. Is it science that satisfies man's soul, or is it the attendant feeling and imagining which the study of Nature evokes?

There have always been men of science, tough-minded by birth, to whom an enthusiasm for natural knowledge has been in itself enough, who have asked for no satisfaction from either faith or feeling; and the world owes much to their preoccupation. But this has not been true on the whole; the unsatisfyingness of an exclusively scientific view of Nature has been confessed age after age.

In the ages of the empirical order Man had his imaginative constructions of early magic and of early animism. These were attempts to eke out very imperfect understanding and very imperfect control of Nature, but they were also sops to feeling. The replacement of the empirical order by the scientific order was great gain. It meant a less beclouded intellectual sky and a greatly increased mastery of natural resources. But with the gain came loss, for the reconstructions of science are austere, not home-like to the human spirit. The creations of early days—the attractive elves as well as the repellent gnomes—were scattered by the growing light of science, save a few which found refuge and here and there still linger in the caverns of Man's mind. There is no doubt that the scientific method is antipodal to feeling, and that scientific methods and systems are almost hostile. So we tend to get further away from “an original relation to Nature”, such as many children have, such as Emerson referred to when he said: “The earlier generations saw God face to face; we through their eyes. Why should not we also enjoy an original relation to Nature?”

It might be thought that the more science grows the more feeling should deepen. “All knowledge,” Coleridge said, “begins and ends with wonder, but the first wonder is the child of ignorance, while the second wonder is the parent of adoration.” Truly progressive science should enrich our feeling, for it gives to our vision depth, order, connectedness, and continuity, and makes the whole world more translucent and more full of meaning. But we have, after all, to admit that the light of science is as cold as it is clear. Keats was right in lamenting that the rainbow had never been quite the same, in spite of what Wordsworth said, since Newton looked at it with his discerning eye. No doubt that for any wonder Science dissipates, she gives us twain; but they are not the old homely wonders. No doubt, though Science is ever pushing the curtain back a little further, so that half-wonders disappear, the wonder remains. But the fundamental mysteriousness of Nature is cold comfort for the loss of the wonder of the rainbow and of the Northern Lights, of the flower in the crannied wall and of the way of the eagle in the air.

The fact is that it is rather the scientific mood than science that is opposed to feeling. For the eyes of the investigator have neither laughter nor tears. In the actual work of science, emotion is dangerous. For scientific purposes we must look out of one window only and with all possible concentration. It has been said, though it is a dangerous half-truth, that the worst kind of comparative psychologist is the observer who is devoted to his animals.

Especially since Darwin's day, we have been learning in biology to see creatures in their spatial and temporal linkages, but it cannot be denied that the predominant method of science is analytic and deliberately abstract, whereas the tendency of feeling is always to see things whole—synoptically. As Goethe said, “these dissecting operations, ever and ever continued, produce likewise many a disadvantage; the living is indeed analysed into elements, but it cannot be brought together again out of them and animated”. Compared with the biologist's insight the shepherd's outlook is superficial, but unless the biologist can reconstruct and reanimate he has lost that view of things in their totality which the shepherd has. We may have a profound knowledge of the life-history of a creature and yet fail to get that imaginative vision which the authors of Animal Biographies have with less material made their own.

In the attempt to conserve what is reached through feeling, to which Man instinctively tries to hold firm, satisfaction has been sought in Nature-poetry, in symbolism, in Natural Theology, or in an idealisation of Nature in a religious halo. These avenues of satisfaction, these pathways to reality, for the two phrases mean much the same, remain happily open to many. To others, however, they are closed, partly because of the austerity of the scientific mood and partly because there is a lack of correlation. Thus much Nature-poetry is too like antiquarian or reminiscent architecture, evading the problem of idealising the present in offering us constructions whose beauty makes us forget for the time that they are anachronisms. Similarly, the spiritualisations offered by philosophy and by theology have often seemed unconvincing because imposed from without, instead of arising in minds saturated with the actualities of the case. It goes without saying that there have been poets, philosophers, and theologians who have seized on the universal elements in Nature which are for all time. It is also obvious that Nature-poems may be literary treasures though they are no longer significant to us in our world-outlook. But what we want to get at is simply this: What counteractives or compensations may there be for those in whom the scientific mood is strong, in whom neither Nature-poem nor ancient Theodicy, neither philosophical idealisation nor fairy tale finds satisfactory organic response.

To conserve the feeling for Nature—at once a satisfaction and a clue—we may get what aid we sincerely can from Nature-poetry and other idealisations, we may give greater breadth and depth to our vision by more science, we may exercise ourselves in scientific reconstructions till the Dryad comes back into the tree, but all these are vanity unless we keep close to the concrete realities themselves, and receive with open minds the great primal impressions of immensity, flux, order, intricacy, and beauty, not refusing to be thrilled by what seemed to our more naïve predecessors to be immediately divine.

There is grandeur in the spectacle of the star-strewn sky, so apparently crowded, but there are thousands of worlds unseen for every one our unaided eyes can image, and yet the astronomers tell us that the emptiness of space is its most striking characteristic. We are staggered by the fact that when we look at α Centauri, which lies some ten billions of miles nearer to us than any other known star, we see it, not as it is to-night, but as it was four years ago. We have no mental picture of the remoteness of the sun, which is the earth's ‘mother-country’, but if the sun were represented in a model by a grain of sand one-hundredth of an inch in diameter, and the earth by a quite invisible speck one inch away, the nearest star would be represented on this scale by another grain of sand some four miles off. One knows indeed that size and distance are in a way the least important distinctions in the world, but just as men often lose their littleness in sojourning among the great mountains, so it is part of the significance of things to us that we belong to a system cast on big lines. We are citizens of no mean city.

No one supposes that we are divided into scientific, æsthetic, and other parts, and function in bits as it were; or that there is an antithesis, like good and evil, between science and feeling; or that there is any such thing as ‘pure perception’. As a matter of fact, as Professor Ritter says, “We know-and-feel, all in one breath, whenever we respond in an unsophisticated, natural manner to contacts with men and things” (1911, p. 126). Deeper science may deepen feeling, and deeper feeling may lead to deeper science. We are inclined to agree with Ritter that “we cannot interpret plant and animal life broadly and soundly either in technical science or in common intelligence unless the æsthetic side of our nature joins with the intellectual side in determining our attitude toward the beings we deal with.” Progress is to be looked for in correlated, not dissociated development. There is no question of allowing feeling to influence our calculations or measurements, for the scientific accounts are open to public inspection and are fortunately audited with severity. But we need not think that the ark of science has such an unstable equilibrium that a touch of imaginative insight will upset it. There is no question, on the other hand, of admitting into our feeling for Nature any element that is incongruent with our intellectual experience. That way lies sentimentalism or worse. But we need not be too timorous in our anthropomorphism or afraid of exaggerating the wonder and subtlety of Nature. We cannot, for our life's sake, and for the sake of our philosophical reconstruction, afford to lose in scientific analysis what the poets and artists and the lovers of Nature all see. It is intuitively felt, rather than intellectually perceived, the vision of things as totalities, root and all, all in all; neither fancifully, nor mystically, but sympathetically in their wholeness. There is a deep wisdom in Wordsworth's remark in one of his Prefaces:—“Poetry is the breath and finer spirit of all knowledge; it is the impassioned expression which is in the countenance of all science.”

To all those who remind us what “a dubious and varying oracle” feeling has proved to be in the past, we would answer, “But how often a wise counsellor!” In an exalted mood many have in the light of feeling made decisions from which the happiness of a lifetime flowed, and it was a wise man who declared that great ideas come from the heart. We mean by feeling in its finer expression the lamp which others have called intuition. It goes out if not tended, and if facts do not form part of its oil the flame will sputter. But it is a light in the region ‘beyond science’. As M. Bergson writes, “Sur notre personnalité, sur notre liberté…sur notre origine et peut-être aussi sur notre destinée, elle projette une lumière vacillante et faible, mais qui n'en perce pas moins l'obscurité de la nuit où nous laisse l'intelligence.”

The words “The Unfathomed Universe”, used in the title of this lecture, were suggested by Walt Whitman's well-known line—“Prais'd be the fathomless universe, for life and joy, and for the objects and knowledge curious.” Whit-man assuredly strikes the right note—that of the joyous adventurer sailing into opulent seas unexplored. Wherever in the past he has sounded he has touched treasure, he looks forward to winning the secrets of deeps still unfathomed. Experience never disappointed surely warrants a feeling of expectancy, an impression of inexhaustible riches—“these immense meadows, these interminable rivers”, horizon beyond horizon, which are ours, here and now, to seek to appropriate.

The climax of intuition is mysticism, and those of us who do not practise it must not brush it hastily aside. Many mystics are precise and logical thinkers—though they explore a kingdom beyond science and logic. Some psychologists have suggested that in conditions of quiet or of exaltation, as in the presence of fine scenery, there may enter into the focus of consciousness some larger area of the unconscious mind than is usual in ordinary life. Others believe that the mystic is thrilled by extra-human influences. All that we plead for is a recognition of the fact that practical men and women of to-day do still manage to get into an original relation with Nature. In his Candle of Vision (1918), A. E. writes:

“I draw attention to the mystery in common and obvious things, and ask that they be explained and not slurred over as if no explanation were necessary. I ask the doubters of my vision to penetrate a little into the mystery of their own thoughts and dreams before they cry out against me, who for many years travelled far and came upon lovely and inhabited regions to which I would also lead them. I know that my brain is a court where many living creatures throng, and I am never alone in it. You, too, can know that, if you heighten the imagination and intensify the will. The darkness in you will begin to glow, and you will see clearly, and you will know that what you thought was but a mosaic of memories is rather the froth of a gigantic ocean of life, breaking on the shores of matter, casting up its own flotsam to mingle with the life of the shores it breaks on.”

And speaking of the concentration required in the habit of vision, he says: “It is an exercise this, a training for higher adventures of the soul: it is no light labour. The plough-man's cleaving the furrows is easier by far. Five minutes of this effort will at first leave us trembling as at the close of a laborious day.”

Surely students of science should be the last to dogmatise as to the possibilities of this life of ours.

§ 6. Towards a Philosophical Interpretation of Nature.

As the scientific order transcends the empirical, it is transcended in turn by a philosophical order which aims at a harmonious interpretation of our experience as a whole. The essential change is often referred to as passing from the ‘how’ to the ‘why’, from analytic and historical description to interpretation, but there is also this difference that while science must keep feeling at an arm's length, philosophy seeks to give a view of the world that will satisfy the claims of feeling as well as those of the understanding. It is just our outlook on the whole of life, the world within as well as the world without, and it includes the assets of feeling as well as intellectual gains.

To illustrate concretely: biologists are easily satisfied with their outlook on animate nature if they are willing to leave out of account the fact of human personality at its best, or the fact of human society. We may define our biology so as to exclude them,—that is a question of method,—but to think of leaving them out in our total interpretation of our experience is to allow the light that is in us to be darkened. Similarly, although there is great difference of opinion in regard to the philosophy of the beautiful, there is general agreement that our total outlook on Nature is to be distrusted if the fact of beauty has been ignored. Feeling is to be excluded from scientific investigation, but it must be allowed to operate in our philosophical synthesis. Perhaps we may say that feeling supplies the mortar in which are laid the stones contributed by Natural Science to the (synoptic) edifice which the genius of Philosophy is building.

There are several hopeful indications of an advance towards a philosophical order of Nature. The first is the increasing correlation of the sciences, which are parts of one endeavour to understand the order of Nature and Man's life in its midst. The sciences work into one another's hands in correlation, and this has always been fruitful, as is well illustrated by the transforming and vitalising of chemistry after it joined hands with physics. The scientific study of animal behaviour, still in the freshness of its youth, shows us the effectiveness of a combined attack—psychological and biological—on a difficult set of problems. The autonomy of biology is not inconsistent with its correlation—imperium in imperio—with chemistry and physics on the one hand and psychology and sociology on the other. While the sciences are separated off for the sake of clearness, because they pursue different methods, use different tools, and sum up in different kinds of formulæ, they work into one another's hands, and they are simply different modes of one rational inquiry. Their mutual influence is increased, not decreased, when each recognises its abstractness; and the hope of their leading on to a philosophical order is in proportion to the clearness with which it is recognised that a synthesis is not additive.

It is customary to speak of the unity of the sciences, and no doubt they are beginning to form a system or hierarchy, but the ideal of one science of Nature—the ideal of Descartes, of Hobbes, of Leibniz—is giving place to an ideal of correlation rather than of unity. There has been much profitable breaking down of artificial partitions, much fruitful co-operation of several sciences on one problem, many a useful discovery of a common denominator bringing apparently disconnected facts into comparable relationship, but the materialistic proposal to make physiology a branch of physics, and psychology a branch of physiology, has not been substantiated. Biology and Psychology remain autonomous, with categories of their own. Treating of the work of science, Prof. A. E. Dolbear writes: “By explanation is meant the presentation of the mechanical antecedents for a phenomenon in so complete a way that no supplementary or unknown factors are necessary.” If that kind of explanation were feasible throughout, there would be one science of Nature, in terms of ideal motions, expressible in mathematical formulæ. But this is false simplicity; it does not really work. Thus, to take a clear case, in the higher reaches of animal behaviour, most biologists admit the necessity of invoking other than mechanical factors.

The second hopeful sign we have already referred to, the frank recognition on the part of science that it is not its rôle to solve the riddles of the universe. It remains more or less open to students of science to deny the feasibility of any solution and to doubt the value of any generalisations save those called scientific, but there has been perfect openness in the retreat from the position of world-interpretation. No longer should it be possible to ask, as the title of a not very ancient book does, “God or Natural Selection?”, for that is opposing an interpretative concept to a descriptive formula, in short, trying to talk two languages at once.

The third hopeful sign, as it seems to an outsider, is a change on the part of Philosophy in its relations with Science. There is a growing recognition that Philosophy must use in her characteristically interpretative reconstruction all the general results of the sciences. The Procrustean attempt to force the facts of Nature to fit a premeditated abstract intellectual scheme is not more promising than the antipodal attempt to wring a philosophical system out of Nature alone. The reaction of Lotze from Schelling may serve as a diagrammatic illustration of what is now taking place in our midst; that philosophy is using the best that science can give, and is systematising that along with the other winnings of the developing human spirit.

Prof. A. E. Taylor gives (1909, p. 192) a luminous statement of the relation between science and philosophy:

“The work of the Philosophy of Nature and of Mind only begins where that of the experimental sciences leaves off. Its data are not particular facts, as directly amassed by experiment and observation, but the hypotheses used by experimental science for the co-ordination and description of these facts. And it examines these hypotheses, not with the object of modifying their structure so as to include new facts, or to include the old facts in a simpler form, but purely for the purpose of estimating their value as an account of ultimately real existence. Whether the hypotheses are adequate as implements for the calculation of natural processes is a question which Philosophy, when it understands its place, leaves entirely to the special sciences; whether they can claim to be more than useful formulæ for calculation, i.e., whether they give us knowledge of ultimate Reality, is a problem which can only be dealt with by the science which systematically analyses the meaning of reality, i.e., by Metaphysics. We may perhaps follow the usage of some recent writers in marking this difference of object by a difference in terminology, and say that the goal of experimental science is the description of facts, the goal of Metaphysics their interpretation. The difference of aim is, however, not ultimate. Description of facts, when once we cease to be content with such description as will sub-serve the purpose of calculation, and call for the description of the fact as it really is, of itself becomes metaphysical interpretation.”

Along with the sympathetic interest that many modern philosophers (such as Ward, Royce, Pringle-Pattison, Stout, Taylor, Lovejoy, Bergson) have taken in the general results of science, there is benefit accruing to science through their expert criticism of scientific categories. For the mood and training of the scientific investigator is rarely such that it leads far in that direction. Some of the ablest scientific minds the world has known have betrayed in their would-be philosophical deliverances an extraordinary naïveté.

In thinking of the empirical, scientific, and philosophical orders as reconstructions of increasing completeness and, it is hoped, of increasing nearness to reality, it must be remembered that they co-exist in our midst like outcrops of strata of different epochs. Thus we have little more than empirical knowledge in regard to the variability of living creatures, or in regard to certain obscure diseases. In medical practice, stock-breeding, and engineering, empirical knowledge has often worked extraordinarily well. The explanation is sometimes diagnostic genius, sometimes remarkable development of perception in quite ordinary individuals. A patiently accumulated working knowledge often leads a shrewd man a long way without much science in the strict sense. Similarly there are many who have established for themselves scientific order over large areas, but have not sought to correlate it with other parts of their experience, thus failing of philosophical endeavour. And others who seek do not find. Similarly, many scholars who have a philosophy of history have neither a philosophy nor a science of Nature. It is to be recognised, then, that the empirical, the scientific, and the philosophical order co-exist in us and in our midst.

Another note may he permitted. It has often been pointed out that progress in intellectual construction is correlated with mastery of environing conditions. As compared with the early working knowledge, the scientific order meant increased control of Nature, and as science has grown our mastery has widened and deepened. We have only to think of the successive harnessings of wind, water, steam, and electricity. Preventive medicine and hygiene, the arts of agriculture and breeding are good instances of the passage from control of the inorganic to the control of organisms. When we look around and see how much men suffer from a partiality of view that is remediable and from philosophies which are discreditable, is it too much to hope that the growing philosophical order is going to lead us to an increased control of the higher issues of life—an aid which Religion will be unwise to refuse?

§ 7. Science and Religion.

Science is frankly empirical in method and aim; it seeks to discover the laws of concrete being and becoming, and to formulate these in the simplest terms, which are either immediate data of experience or verifiably derived therefrom. The scientific ‘universe of discourse’ does not include transcendental concepts; its aim does not include attempting to give ultimate explanations.

Religion has been described as the orienting of our life towards the True, the Beautiful, and the Good. But this does not grip; it leaves out the essential—the mystical—element. Religion in essence always implies a recognition—practical, emotional, and intellectual—of a higher or deeper order of reality than is reached in sense-experience. It means the recognition of an unseen universe, which throws light on the riddles of the observed world—a light which may give aid. In the scientific light of common day are seen the hosts of the Assyrians encompassing the city; the opened religious eye sees the mountains crowded with the chariots of God.

But let us quote an authority. Prof. D. S. Cairns writes (1918, p. 21): “Religion is, fundamentally, on the human side, man's protest and appeal to the Supreme against the sorrows, indignities, and sins of this present world. It is the endeavour of man, through that appeal, to unite himself with the life of that unseen and ruling world, and so to win the power from it to dominate and transmute the life of time. That is to say, in essence, religion, on the human side, is simply the sustained endeavour to meet this great human problem of the destroying Nature and the struggling personality. All religions have this at their heart. They, one and all, start from an act of faith in an unseen world which is mightier than the world of sense and time, and which is either already friendly or may be made friendly to the worshippers.” He goes on to say that in all religions there may be recognised three great constant elements—the conception of an unseen ruling world, some idea of the supreme good which the worshipper may derive from Heaven for the enhancement of his life, and some way or means of uniting the worshipper with God or the gods.

It is evident, then, that the religious language is not the scientific language, and that it is impossible to intermingle the two. The religious concepts are different and apparently more metaphysical; their aim is interpretation rather than description. In short, science and religion are incommensurables.

But to call religion and science ‘incommensurables’ is not to fall back on the old-fashioned impossible device of having idea-tight compartments. Just as a novel scientific generalisation is not incorporated in our scientific system unless consistent with previously established conclusions, or unless the latter can be adjusted to meet the new idea harmoniously, so at a greater height, where philosophical discipline is invaluable, a religious idea, such as that of a Divine Creator, must be congruent with the rest of our world-picture, e.g., with the idea of evolution. It is the criterion of consistency that saves from superstition.

Men are led to religion along many pathways—from the perplexities of the moral life, from an appreciation of the facts of history, and from the experience of reaching the limits of practical endeavour, of emotional expression, and of intellectual inquiry. When we think of the last-named three pathways to religion, which many tread,—through baulked struggle, over-strained emotion, and baffled search after clear understanding,—we can see why the rapid development of science should, for a time of transition at least, work against religion. For science gives Man from time to time a greatly increased mastery over Nature; science, with its analytical triumphs, ever tends to diminish, in the shallowminded, the saving grace of wonder; and science is ever dispelling the darkness that oppresses the mind. Moreover, the scientific mood, inherently sceptical, has been widely diffused; its activity has a growing fascination of its own; it easily comes to preoccupy the mind, and thus tends to crowd out the æsthetic, the poetic, and the religious moods. And yet we believe that religious interpretation and scientific analysis are equally natural and necessary expressions of the developing human spirit.

When we are thrilled with the wonder of the world, the heights and depths of things, the beauty of it all, we approach the door of natural religion. And when the Nature-feeling is not superficial but informed with knowledge, with no gain of the hard-won analysis unused, we may reach the threshold. And when we feel that our scientific cosmology leaves Isis still veiled, and when our attempts at philosophical interpretation give us a reasoned conviction of a meaning behind the process, we may perhaps enter in. That the entrance is not easy is shown by the unhappy prevalence of a profane world-outlook outside the ranks of disciplined thinkers and investigators, on the one hand, and religious, poetical, and artistic lovers of Nature on the other. The difficulty of the entrance is partly due to race, for North Temperate peoples with no Celtic strain never find religion easy, partly due to preoccupation either with the good things or with the thick shadows of this life, and partly due to a misunderstanding of the results of science. It is the last hindrance to religion that concerns us in this course of lectures.

What must be worked towards is a philosophical co-ordination of the essential results of Biology and the other sciences with the results of intellectual inquiry in other fields and by other methods, allowing at the same time for those glimpses of reality that feeling alone affords. In this task it is all-important that we get at the facts, for there are currency many conclusions in regard to Nature which can no longer be accepted as well grounded. What we may reach can only be provisional, for the data of science are in process of rapid change; but there will be some reward if we can eliminate some spurious and obsolete coinage.

Whatever be our philosophical interpretation or religious conviction, we do well to have more than a passing acquaintance with the world without, with the process of which our life is part. The aim of this course is to state the general results of biological inquiry which must be taken account of if we are to think of Nature as a whole and in relation to the rest of our experience. The first part of the course will deal with the realm of organisms as it is—so far as its changefulness permits; the second, with its evolution,—past, present, and possible.

SUMMARY.

In primitive times man had a slowly growing recognition of an empirical order of nature, a very imperfect control of natural forces, and a theory of magic or of animism.

The empirical order has gradually given place to a scientific order, ever broadening and deepening; and man's control of Nature has increased in proportion. One science has been added to another in elaborate specialisation, and there has also grown up a scientific system or ‘world-outlook’ which verges on philosophy. This world-outlook has ceased to be geocentric or narrowly anthropocentric. The reign of law and the process of evolution have been recognised.

The direct motives of scientific inquiry are, in the main, intellectual curiosity, a self-preservative dislike of obscurities, a desire after unity and continuity in our outlook. It is a quite specific endeavour to get things under intelligent control, so that we can think of them clearly in relation to the rest of our knowledge, and so that we can act effectively on the basis they afford. The aim of science is to describe natural phenomena as precisely as possible, as simply as possible, as completely as possible, and as consistently as possible. But this view of Laws of Nature as merely descriptive formulæ must not be exaggerated; the formulæ often imply a great deal of preliminary analysis and reduction, which is ‘explanation’ of a sort; they must be verifiable by all normally constituted minds; and that they bear close correspondence to the actualities of Nature is shown by the way in which we use them safely in prediction. Moreover, the descriptive formulations of science must, in relevant cases, be followed by a historical or genetic account of the subjects of study—especially, of course, when we are working within the boundaries of the realm of organisms.

The limitations of natural knowledge are great. We know Nature only in the mirror of our minds; we are limited by our senses; we cannot make scientific progress without taking partial or abstract views, and the correlation of these is difficult; our fundamental concepts (like ‘matter,’ ‘energy,’ ‘organism’) are not self-explanatory, but big with mystery; they are not final, but in process of development; the law of gravitation is perhaps the finest example of a far-reaching descriptive formula, but it does not tell us why the apple falls to the ground; in some departments of science we try to give historical descriptions or to trace genetic series, but we know little of any beginnings; the world is full of unsolved concrete problems—thus such a common phenomenon as cell-division remains in great part an enigma; there are hints of facts beyond our present horizon; and so on. In an age of extraordinarily rapid scientific discovery, we stand wondering before an unfathomed universe.

The world without has played an important part in the evolution of the human spirit. Its enigmas have educated our intelligence; its practical problems have trained our will; and in Animate Nature in particular Man has found a school of feeling. In her varied opportunities Nature has helped in polishing the mirror of our minds in which we see her, and there is no reason to believe that the polishing is finished. As regards feeling for Nature, however, the scientific mood, now so dominant, is antipodal, and the scientific systematisations may be actively hostile. Nature-poetry, symbolism, Natural Theology, philosophical idealisations, and religious spiritualisations—valuable as they may be to attuned minds—fail in many cases to find any satisfactory organic response, and the life of feeling has been impoverished. Yet to try to leave feeling out in our view of Nature is to try to close one of the right-of-way paths to reality. To conserve this element of feeling, to which the analytic mood of science is opposed, it is above all necessary to keep close the concrete realities themselves, keeping an open mind to their influences. In this endeavour science may be of use, as a means of culture rather than as an intellectual formulation, adding depth, order, and connectedness to our vision. In the cultivation of feeling, which requires to be kept well in hand, mental elbow-room must be given to the fundamental impressions of immensity, flux, order, intricacy, and beauty.

Movement towards a philosophical Order of Nature, i.e., towards a harmonious interpretation of Nature along with the rest of our experience, may be discerned in the growing correlation of the sciences, in the re-definition of their aim (descriptive rather than explanatory), in the aid that has been given to science by philosophical criticism of its categories, and in the endeavour that is increasingly made by philosophers to take the results of science into their consideration. Perhaps it may be said that feeling supplies the mortar in which are laid the stones contributed by Natural Science to the edifice which the genius of Philosophy is building.

When we are thrilled with the wonder of the world, the heights and depths of things; when our Nature-feeling is informed with knowledge; when our science leaves us with a conviction of the mysteriousness of Nature—the unfathomed universe; when our philosophical outlook leads us towards a realisation of a meaning behind the process; then there may be a total reaction on our part worthy of the name of Natural Religion. To facilitate this reaction—by an accurate presentation of the facts—is one of the objects of this course.