In this concluding lecture I shall endeavour to sum up the reasoning which I have laid before you, which, needless to say, is simply an attempt to bring consistency into the inheritance which has come to me individually in science, philosophy, and religion. That inheritance has been received from sources which can be traced backwards through the history of many nations to dim antiquity; and it is much the same inheritance as, in Scotland particularly, very many have received. Perhaps, however, it has come to me in such a manner as to bring the apparent inconsistencies in it into specially sharp outline, for it came very directly through those who were nearest to me.
In the first course of lectures I reviewed the various kinds of knowledge, or sciences, which seem to be forced upon us in our actual experience. We can divide these sorts of knowledge into mathematical, physical, biological, and psychological or humanistic knowledge. These kinds of knowledge are just different kinds of interpretation of our experience, and on them are based different kinds of occupation or behaviour; but they seem to contradict one another, and we seem to be constantly passing inconsistently from one kind of interpretation and behaviour to another.
The mathematical sciences deal merely with time-relations (arithmetic and algebra) and space-relations (geometry). We can count events regardless of their inter-connexion, their importance, or the intervals between them. We can also reason about shapes without regard to what the shapes are of, or how far or in what sense actual shapes correspond to them. Thus the mathematical sciences deal quite evidently with ideal abstractions which we at once recognize as such. I therefore passed lightly over the mathematical sciences, as in recent times since Newton we have not been much perplexed by them.
It is very different, however, with the physical sciences, since the physical interpretation of our experience, as given definite form to by Galileo, Newton, and their successors, has claimed to represent visible reality itself; and round this particular claim the main problems of modern philosophy have centred. I pointed out that on this claim visible reality consists of “bodies” existing independently of one another in space and permanently in time, each body possessing definite fundamental properties of its own, and acting at different times on other bodies in such a manner that their actions and reactions can be summed up as energy, which is just as indestructible as the bodies themselves, and is constantly passing from body to body.
Without waiting to discuss the direct philosophical objections to this interpretation, I then proceeded to consider the biological interpretation of visible reality; and this occupied several lectures, as biology has suffered severely from the failure of its representatives to put their science into coherent form, though they have evolved a large and characteristic body of knowledge and a distinctive nomenclature. The science is there, but the form in which it is commonly summed up is very deficient, owing to their having been overborne by the physical interpretation.
Up till about the middle of last century most biologists had attempted to interpret the experience they were dealing with on the “vitalistic” theory that within living organisms, but not outside them, physical influences are interfered with and guided in a specific manner by what was known as a “vital principle” or “vital force,” or, in recent times, as an “entelechy.” This theory, as was pointed out in Lecture IV, was almost universally abandoned, on the very sufficient ground that it can easily be shown experimentally that whatever influence had been attributed to the vital principle depends on the influence of the admittedly physical environment. It seemed, therefore, that biology must in reality belong to the physical sciences; and this became the orthodox conclusion of biologists in the latter part of last century.
In Lectures II and III this conclusion was examined and shown to be completely unsatisfactory and inconsistent with biological observation. It is, moreover, quite impossible to return to vitalism. What the observations necessitate is nothing less than abandonment of the physical interpretation of visible reality, substituting for it the conclusion that in the phenomena of life we have the manifestation of a unity within which physical bodies as such, with their corresponding spatial externality, do not exist, and which includes the environment as well as the bodies of organisms. This unity persists just as do the “bodies” of the physical interpretation; but its persistence is active, since it is only through activity that it manifests itself. The structure which it displays is the expression of activity, and the activity is an expression of the structure.
This is the unity which we call life; and the branch of knowledge which deals with life is biology. It is distinguished from the physical sciences because its fundamental conceptions are different from those of physical science. It is thus an independent science or group of sciences. Both the vitalistic and the mechanistic school in biology had, as it were, sold its birthright for a mess of very unsatisfactory pottage. Looking back on the history of biology we can see how its progress has been retarded or deflected by the misleading mechanistic and vitalistic theories, which led, for instance, to an artificial separation of anatomy from physiology, and to futile theories of heredity and of an origin of life in time.
We cannot express biological phenomena in terms of physical conceptions. Yet biological phenomena are part of our visible world. It follows at once that physical conceptions are by themselves incapable of representing visible reality, however useful they may be. They are thus in the same position as merely mathematical conceptions: they do not express reality. This is a conclusion of great philosophical importance, for we can no longer describe as realism a philosophy which accepts the physically-interpreted world as a representation of reality. The distinction between physics and biology stands, therefore, for something fundamental in philosophy. It cannot be neglected, as it has so often been in the past.
Life has many forms. But for one organism the life of another is simply part of its biological environment, and is thus included in the unity of its life. When, however, we examine the unity of life more closely, we find that it is not, as may at first sight suggest itself, something merely centred in individual organisms or individual cells, or in units of life in a cell, but expresses the life of communities of organisms or cells. The life of the individual organism or cell is thus actually the wider life; and the death of the individual cell, or organism, or even group or species of organisms, becomes only a normal incident in a continuous wider life. With the occurrence of death we do not pass outside of biological interpretation, any more than we pass outside physical interpretation when a solid substance is gasified. From the biological standpoint life is continuous in time, and represents something inherent in the very existence of Nature, just as do matter and energy from the ordinary physical standpoint.
In the sixth to the ninth lectures of the first course I discussed the branches of knowledge concerned with conscious behaviour, this knowledge being comprehensively designated as psychology, though we might also designate it as humanistic knowledge. The fundamental fact was pointed out that both perception and conscious action embody interest, and that this implies, not merely, like life, unity in spatial relations, but also unity in time-relations, so that events in their time-relations, and not merely in their space-relations, enter into the unity. This implies the existence of progress or evolution. What is perceived is perceived in relation to both past and future, as a whole, as well as to present as a whole, since it is of interest; and similarly retrospect and foresight enter into conscious action. The world of psychological knowledge is a world of interest and the values embodying it. For neither physical nor biological knowledge have interest or values any significance, since events in the physical and biological worlds are simply regarded as what may chance to occur, though they must occur in accordance with physical or biological conceptions. In psychologically interpreted knowledge, on the other hand, events are no longer regarded as matters of indefinite “chance,” but as the progressive manifestation of interest and values, which unify the events.
For psychological interpretation present events are inseparable from past and future events, since these events embody interests and values which manifest themselves in time-relations as well as space-relations. We cannot separate their manifestation in time-relations from that in space-relations. History, whether of individuals or countries, is no mere chronicle of isolated events, but the present is the fulfilment of the past and the promise of the future. If we endeavour to regard perceptions and conscious actions as mere isolated events, like physically interpreted events, we are just missing what is characteristic of them, and are thus lost in meaningless abstractions. If, for instance, we endeavour to regard them as being either the interaction between a soul or subject and a material world, or the manifestation of mere life, we are simply endeavouring to do what is impossible. It is meaningless to speak, either of the relation of the soul to the body, or of conscious behaviour as a mere blind manifestation of life.
Just as in the biologically-interpreted world what at first sight may seem to be individual lives turn out to be the manifestations of a wider life, so in the psychologically-interpreted world what appear at first sight to be individual centres of interest and values turn out, as shown by social relations, to belong to social centres. Hence individual interest and personality are swallowed up in the wider interest and personality. We can, moreover, classify apparent values in correspondence with the less real and fundamental, or more real interest which they represent. The former we roughly classify as material, and the latter as ethical or spiritual values.
The survey of different kinds of science or knowledge in the first course of lectures thus led up to the result that the different sciences or groups of sciences represent fundamentally different interpretations of reality, and we may regard these interpretations as the bases of Logic for each science. There are thus no grounds whatever for concluding that the physical representation, however useful it may be for certain practical purposes, is true representation. It is nothing but an ideal representation which breaks down completely when we endeavour to apply it to the facts of biological and psychological experience; while biological interpretation breaks down in presence of the psychological facts of conscious behaviour. The facts of conscious behaviour belong just as much to our visible and tangible experience as other facts, and we cannot neglect conscious experience in framing our conception of what is real.
In the last lecture of the first course I pointed out that it is only in a general manner, and imperfectly, that we can apply the psychological interpretation. In matters of detail we have to fill up the gaps by applying physical or biological interpretation. Thus we seem compelled to regard ourselves as if, in spite of psychological interpretation, the events in our lives exist also only here and now, subject to all the mere chances of a physical or biological universe. It seems also to be the case that even in so far as we interpret our experience and actions in the light of interest and values, the interest and values are to a large extent of a lower kind. Although, therefore, we have got rid of the meaningless questions as to the relation of life to matter, or soul to body, we are still confronted by the question why it is that reality appears to us under the more abstract physical or biological interpretations, as well as under the less abstract psychological interpretation. This is the real question which the sciences propound to philosophy, and which was the subject of the present second course of lectures.
The question confronts us at once when we consider the relation between physical and biological interpretation; and this relation was discussed in the first three lectures of the present course. What is before us is not the meaningless question as to the relation of life to matter, but the question as to the relation to one another of two different interpretations of our experience. I pointed out that it is only on the basis of an accurate preliminary application of physical interpretation in matters of detail that biological interpretation advances. Defective physical and chemical investigation produces only defective biology, just as defective mathematical data produce defective physics and chemistry. It was defective physical and chemical investigation which led to the idea, still widely prevalent, that biology can be regarded as nothing but a branch of physics and chemistry.
When, in placing physical and chemical data in conjunction with one another, we take the phenomena of life into consideration, it becomes evident that these data can only be interpreted consistently on the theory that visible reality implies co-ordinated persistence of activity expressing itself in a correspondingly co-ordinated persistence of structure or arrangement of parts. The fact of the co-ordination, as clearly shown in the phenomena of life, is inconsistent with the fundamental physical assumption that bodies and actions exist in space independently of one another. Hence we cannot form a consistent physico-chemical conception of visible reality, and must regard it, in spite of superficial appearance, as life, making the conception of life not only the basis of the science of biology, but also an ideal for a deeper understanding of the whole of visible reality. It is only, however, through scientific faith, based on a conviction of the consistency of our experience that we make this inference. We certainly cannot see in anything like full detail how this inference applies, and must content ourselves with a physical interpretation of detail where biological interpretation is not discoverable, as it is in what we recognize as the phenomena of life. This means that though the physical interpretation of reality is of great practical service as giving us a limited insight into reality, it never represents reality itself.
When we turn to the facts embodied in the psychological or humanistic interpretation of experience we find that our experience embodies interest and values which extend indefinitely over both space-relations and time-relations. This is just a fact of experience, of which there is no “explanation” any more than there is of the existence, on the physical interpretation, of matter and energy, or, on the biological interpretation, of life. For psychological interpretation the spatial and temporal arrangement of things and events are not relations of externality or separation, but expressions of their own nature, which extends through all space and time relations.
It is when what might otherwise appear as isolated events in mere blind organic life are considered together that the necessity for psychological interpretation appears. Thus psychological interpretation, though it is an inherent aspect of experience, can grow in definition only through preliminary biological interpretation, just as biological interpretation can grow in definition only through preliminary physical interpretation. In this sense psychological interpretation is based on biological, and biological on physical interpretation. Thus we can regard both biological and physical interpretation as nothing but the first stages in psychological interpretation, and therefore parts of it.
Interest and values are no mere individual interest and values, but, in so far as they are what we call spiritual interest and values, are common to all men and extend indefinitely beyond mere human society. Hence they appeal to us as being objective or the same to all. But since biological and physical interpretation are the first stages in this objective interpretation, they also appeal to all men as being to this extent objective. They are not objective by themselves, since they are by themselves quite incapable of interpreting our experience, but as the first stages in objective psychological interpretation they become objective in the sense that they appeal to all men. In this sense the mathematical, physical, and biological sciences belong to the world of spiritual values, and imply no opposition to, or separation from, that world.
The universe of spiritual interest and values would be inconsistent with itself if it were not one spiritual universe, corresponding to what, in the language of religion, we call God. God is thus the only final reality, and individual interest or personality has its only reality in God. From this standpoint existence in time is just the progressive manifestation of God. The existence of God and His love is a primary and fundamental fact, the presupposition of all experience or of what we call Nature; and it is solely in our perception of spiritual values and faith in their unity that the existence of God is revealed to us. Through this faith we identify our own wills with God's will when we strive for what presents itself to each of us as his or her own particular duty.
In the light of this conclusion we must reject without any hesitation the theory that reality is represented by the mere physical interpretation of what we perceive. The physical interpretation is only objective as a stage in spiritual interpretation. Hence we must reject materialism in every shape and form, and without the smallest compromise. In doing so we at the same time vindicate the place of the mathematical, physical, and biological sciences in the world of spiritual values. The sciences are in no way hostile to, or outside of, the world of spiritual values, but an essential part of it. As a representative of one of the sciences I must insist on this claim.
We must also reject a great deal of what, as the-logy, is at present usually associated with religious belief. Current theology is full of what seem to me to be materialistic beliefs which obscure religion and deprive the Churches of co-operation, just as the work of a scientific organization would be injured if its investigations were only carried on in the light of obsolete scientific conceptions. The theory that God is a person distinct from His creations, and created the Universe in time as a mechanical universe, seems to me to be a mere compromise with the materialism for which visible reality is physical reality. There is no physical reality outside God: the assumption that there is such reality is only materialism which must be firmly and decidedly dissociated from religion.
Another theological belief which must be rejected is that religion has only come to us by a “supernatural” revelation. This is also part of the materialism which assumes that our universe is not a spiritual universe in which God is revealed to us everywhere and at all times if we will only open our eyes. That God and His love are everywhere present amid our apparent world of sin and sorrow was the real message of the Founder of Christianity, and this message was only put then into a much truer and deeper form than that in which it had previously existed. It is for the representatives of religion and philosophy to make that message stand out still clearer and more cogent, as representing a faith which is the inspiration of everything that has true value, and that represents real progress.
Ever since physical interpretation was definitely formulated and applied, the idea of a real physical universe has seemed to menace more and more all that we include under the description of spiritual values. The apparent menace has come to a head in our times. I have tried in these lectures to face it without the slightest flinching. It has turned out that physical interpretation is only a preliminary ideal interpretation, and is therefore no menace at all. The time is not far distant when our successors will look back with wonder at the materialistic superstition of the times we are living in: for materialism is nothing better than a superstition, on the same level as a belief in witches or devils. There are earnest, conscientious, and unselfish materialists, just as there are, or have been, earnest, conscientious, and unselfish believers in witches, devils, and hell. But all these beliefs will go the way of other superstitions; and the world will be well rid of what has tended only to obscure religion.
A further unfounded theological belief is that there is a soul existing in space and time independently of a merely material body from which it parts at death. This belief is also part of the materialism of current theology. A material world as such does not exist, nor have mere individuals as such any real existence. The only reality is in God, and we are one with God in so far as we are realizing the spiritual values in the progressive realization of which His existence is expressed. These values are not individual values, and death of the individual does not imply a partial extinction of them.
It is only through want of faith, and corresponding failure in surrender of our individual interests to God's interest, that we fear death and look for personal immortality, or regard our interest as a merely personal interest commencing with birth in a surrounding material world. Death or personal calamity or advancement should be regarded as only an incident in the fulfilment of God's will. So it is that a brave sailor or soldier meets death in battle, or meets either neglect or the conferment of personal honours. We can all die like brave sailors or soldiers, trusting in God as they do, though to them trust in God may take the form that their comrades and their country will carry on in the duty which stands above any mere individual interests.
Belief of any kind in what is supernatural seems to me to imply a faltering in religious faith. For religion, Nature is nothing but a manifestation of God, so that the very idea of anything supernatural is contrary to religion. It is only in so far as we have accepted a materialistic and thus totally irreligious interpretation of visible reality that belief in supernatural interference has to be brought in as a feeble make-weight. It seems to me that the sooner religious belief is dissociated entirely from belief in supernatural interference, the better will it be for humanity. Apart from other considerations, men of science, in so far as they are true to the high ideals which inspire their work, will never accept any belief in supernatural interference. Belief in the self-consistency of the universe is for them equivalent, in ultimate analysis, to belief in the existence of God, and is thus something sacred and not to be tampered with for any consideration whatsoever.
In the course of these lectures I have brought you into contact with the deepest and most far-reaching questions which we all have to grapple with in some sort, and I have given you the results which have been forced on me in the course of a life now drawing to its close, but during which these questions have been constantly present. I am glad that the lectures have been given before a Scottish audience; for I think that it is by an audience of my own countrymen in the narrower sense that the arguments which I have presented, and the manner of their presentation, will be most readily understood, since philosophy, pure science, and theology have come to flow to an unusual extent together in the blood of Scotsmen. These lectures have not been in the form of practical sermons. Nevertheless they seem to me to have practical applications in various directions; and in concluding this last lecture I wish to glance very shortly at some of these applications.
In the first place, I think that the interpretation which was given of the true aims of biology and its consequent place as an independent science has bearings of the most direct kind on the teaching and practical applications of the biological sciences and on the direction of future investigation and progress in these sciences. Both biological teaching and biological investigation seem to me to have been held back owing to the inadequacy with which the aims of biology and its true place among the sciences have been understood. As a science it is in reality one, and the disastrous theoretical separation of physiology from anatomy ought to disappear, together with corresponding misconceptions in Medicine and Agriculture.
As regards psychology also, the practical applications seem very clear. For if the conclusions placed before you are correct, psychology is an independent science distinct from biology or physics, with fundamental axioms of its own. Under the guise of psychology the world is being flooded with literature which consists partly of very imperfect physics, partly of equally imperfect physiology, and partly of a gross and often extremely nasty misrepresentation of human nature. All this upsets old beliefs, but puts nothing but a far worse muddle in their place; and since psychology is a subject of the utmost importance, the importance of placing it on a sound theoretical basis as an independent science is very great. In actual fact it is represented, though not specifically as a science, in all the humanistic branches of knowledge.
The practical importance of philosophy in bringing consistency into the relations between different kinds of knowledge was taken for granted at the outset of the lectures, and must have become more and more evident as the discussion advanced. Of all the very foolish ideas current at the present time none is, I think, more foolish than the idea that philosophy is useless and has made no progress since antiquity. I am bound, however, to admit that I have only as yet myself encountered this idea as originating south of the Tweed. Those who, in modern times, think that they can do without philosophy, and at the same time without religious belief, are invariably the victims of bad and obsolete philosophy; and unfortunately these victims have been very numerous in the ranks of men of science, owing to their defective education in philosophy. Philosophy, to be effective, must however, be in constant living contact with the sciences, from which her questions come. She becomes impotent if she is not fully aware of the sharply defined questions which are constantly being presented to her by the sciences.
The practical applications as regards theological teaching and its embodiments in the creeds of Churches are very direct. I have not avoided or touched only lightly on this subject, since I feel that it is of vital importance. These lectures will have been in vain if they have not produced the conviction that religion, which is, in reality, only philosophy under another name, is a matter of supreme practical importance. The acknowledged representatives of religious teaching are the Churches, and if they are hampered by obsolete creeds they cannot perform their duty effectively. I pointed out that existing creeds are obscured by materialism in one form or another, and that belief in supernatural events is simply the outcome of this materialism. The clear practical deduction is that such belief should, since it is inconsistent with full faith in God, be eliminated from the teaching of the Churches. I have not the slightest fear for the future of religion, but it seems to me that the influence of the Churches is certain to dwindle more and more unless supernatural belief is banished from their teaching.
When that day comes the Churches will be able to fight practical materialism, and everything in modern life that drags us downward, with weapons which will not fail. Religion will also go hand in hand with the sciences, as it once did, and, like them, will appeal to all men, irrespective of their nationality or scientific conceptions.
When we understand the real evidence that this universe is nothing but a spiritual universe and the manifestation of God present within and all around us, the Churches can again teach, in a manner which will carry general conviction, these old words which have brought strength to go forwards, peace of mind, and charity, to so many: “For I am persuaded that neither death, nor life, nor angels, nor principalities, nor powers, nor things present, nor things to come, nor height, nor depth, nor any other creature, can separate us from the love of God.”