Our view, therefore, is that the concept of materiality can, in the way just indicated, be in all cases analysed into, and derived from, the conception of Energy; and that Science, if consistent, cannot postulate the reality of Matter as well. Potential Energy adequately supplies the demand for a real substratum of which phenomena are the manifestation.

The whole question is very well worth the attention, not only of scientific students but of metaphysicians. The inquiry will distinctly gain if it receive the auxiliary attention of those who have studied the process by which we form our mental conceptions, and whilst the students of Physics deserve the honours of discovery, they cannot safely dispense with such assistance, for which the present confused and inconsistent state of the fundamental definitions of Physical Science most urgently calls. There is here a neglected but very interesting field for the metaphysician's efforts.

Recent scientific writings contain enough to show us that men of science are already beginning to recognise not only the inconsistency of the theory of two real things, but the dominating significance of the conception of Energy, and are gradually coming to claim for the conception of Matter little more than recognition as the vehicle of energetic transmutation. Let us then for the moment accept the position that Science—ridding itself of redundant theory—postulates Energy as the real thing-in-itself, in terms of which it frames its statement of physical phenomena, and let us examine briefly the effects which the acceptance of this new postulate is likely to have on philosophic speculation.

All my Presentment, all the content of my sense-experience, according to this theory, I attribute to a multifarious continuous series of transmutations constantly proceeding in some portion of the system of Energy which constitutes the real substratum of phenomena. I study, measure, and classify the different species of these transmutations; I associate particular sensations and classes of sensations with particular transmutations, and I thence infer the existence in posse or in esse of more or less Energy in some particular form transmuting itself according to some one or other definite physical law. I infer also the existence of various supplies of potential Energy constantly available, and of other intelligent agents like myself.

I associate every such intelligent agent with a particular series or group of sense-experiences, and further I assume that the world at his Presentment, consists for him in a similar series of transmutations continuously going on in that portion of the energetic system which I believe in a similar way to constitute such person's bodily organism. Thus by the same process of reasoning by which I am led to believe that my own Presentment consists in the energetic transmutations proceeding in my organism, I explain the universality of the experience of all intelligent agents. In my own case, by that union of consciousness with physical energy which accompanies the manifestation of life, I am immediately related with that portion of the energetic system which is the real substratum of my organism, and am made conscious of the series of transmutations occurring at that particular point in it which is represented by my sensory system. In the case of others, from certain of the transmutations occurring in my Presentment, I am led to infer the existence of other similar microcosmic systems in the energetic macrocosm of the physical universe.

This is all very well as a theory, but if all I know is the series of transmutations occurring in the portion of the system of Energy related directly to my intelligence, how did I ever learn to infer from these transmutations the existence of that Energy underlying them, and still more of the whole energetic system extending far beyond my organism? How do I deduce from transmutations proceeding in the portion of the energetic system which constitutes the real substratum of my organism the existence, not only of that substratum itself, but of other portions of the system similarly related to other intelligences, and of the energetic system as a whole? How do I get beyond my Presentment? How pass from Ideality to Existence?

I answer that I never could by any chance or possibility have got beyond it or got any suggestion of the Reality had I been merely related to my Presentment as a passive and percipient subject. In point of fact, however, I am in relation with the energetic system not merely or primarily as an Intelligence percipient of the transmutations proceeding in it at a particular point, but also as a Will initiative to some extent of such transmutations and capable of influencing and directing the physical process. Life necessarily involves a process of energetic transmutation constantly proceeding at that portion of the system of Energy which constitutes my organism, and I am there related as Will with a larger system which embraces the part in which intelligence is developed.

Fundamentally, life manifests itself in all grades of the zoologic hierarchy as a union of Volition (or what appears in action as Volition) with some particular point in the universe of physical Energy, the union constituting what we call a living organism.

Despite its profound importance to us personally and to our race, we should not forget that, objectively considered, the brain in man and the higher animals is merely a special organ highly developed by use, as the trunk is in the elephant, the middle phalanx in the horse, or wings in the bird. Intelligence is hardly to any extent a necessity of the vital union of the Will with the energetic system. It is not at all developed in the vegetal kingdom, hardly at all in some branches of the animal, and there may conceivably be an infinite number of other "kingdoms" in which it may be either undeveloped, or very differently developed, or superseded by some other manifestation by us unimaginable. Its development indeed seems to be concurrent with the development of a locomotive faculty—a striking confirmation of the theory that it is in our activity that we derive the suggestions which call forth the exercise of the Understanding and transform sensation into perception.

It is only with a comparative fraction of the organism that I am related as a passively percipient intelligence. I am directly or indirectly related as Will, as an originative cause of activity, with a larger portion of my organism, many parts of which are quite distinct from the cognitive portion. Now it is from my relation as Will with Energy other than and beyond the energetic transmutations which constitute my Presentment that I discover the energetic system of Nature, as a real thing—beyond, underlying, and by its transmutations constitutive of my Presentment. Many of the transmutations which occur in my Presentment I recognise as attributable to my own volitional activity operating upon my energetic organism, and in my own activity there is thus suggested to me a source of phenomena lying beyond these phenomena themselves. A transmutation initiated in my brain is a pure idea. The key which suggests to me the real world is the occurrence of transmutations ascribable to my activity operating beyond the sphere which constitutes my Presentment.

It is in this way that I originally discover the real energetic substratum to the phenomenal world of my Presentment. I learn from the transmutations to infer the agency and operation of the underlying energy, and thus gradually construct my whole systematic conception of the real world in which I live and move and have my being.

This view of my activity and of the consequences of my relation as Will to the energetic system represented by my organism, including the portion thereof related to my intelligence, supplies us therefore with a key to the inevitable reference of thoughts to things.

I distinguish in my active experience a clear difference between wishing and willing, and further between willing and effective action. My Power—the Energy related to my Will—the exertion of which is necessary to translate Volition into an overt result—is a limited and quantifiable thing, but that such a hidden energetic medium or substratum underlies all phenomena is evident from the fact that I do not will directly the appearance of any given phenomenon. I may wish that. But when the Volition is reached and the wish transformed into overt exertion I find myself involved in the multifarious processes of an energetic system which I may so far influence, but which is nevertheless in many ways constantly going on irrespective of my Volition. I may wish to avoid pain and may will certain exertions with that view, but the consequences may be the reverse of what I wished. This shows that the Volition operates immediately not on the sensation but on the energetic system.

In all cases between Volition and overt result there seems to be erected and constantly maintained around me a vast energetic system, a part but only a small part of which, namely the Energy of my organism, can be influenced directly by my Will, whilst, even in immediate relation with that part, transmutations beyond the reach of my Will are constantly going on. Indeed, what fundamentally distinguishes Volition from Desire is its relation to the energetic system.

The doctrine of Energy therefore puts in a new and clearer light the whole theory of Causation.

It is common for philosophers to talk of invariable sequence as the criterion of Causality. But, in fact, that is quite fallacious. No one ever regards a phenomenon as the cause of another phenomenon. We ascribe Causality to the energetic transmutation which in some form or other we inevitably believe to accompany the appearance of every phenomenon. We never postulate a causal relation between day and night—the most notable case of invariable sequence. When we say the fire warms the room, or the horse draws the cart, or the sun ripens the corn, it is the Energy which we rightly or wrongly associate with the visual sensation referred to in the words "fire" and "horse" and "sun" of which we are thinking, and by no means of these visual sensations themselves. As has been well said, we never suppose that the leading carriage of the train draws those behind it, although their relation of sequence is quite as close to it as to the engine.

True, it is and must be from and by phenomena only that I infer and measure the transmutations of Energy, but the transmutations measured are operations of the real thing-in-itself postulated by Science. The existence of such Energy is suggested to me primarily in my experience of my own activity in which I recognise my power of doing work—a quantifiable and measurable thing, homogeneous with the Energy in respect of which Science states the relations and conditions of all physical phenomena. My most incessant mental act is that by which, on the analogy of my own active experience, I refer all phenomena to the underlying energetic system. This reference it is which transforms sensation into perception; and the constant affirmation of this reference is the great function of the synthetic mental activity of the understanding, and is at once the origin and explanation of that imperative mental tendency which metaphysicians call the law of Causality.

How, then, does this doctrine affect the theory of the nature of Space?

If it be true that the world as my Presentment consists in the transmutations occurring in that particular part of the energetic system which constitutes the real substratum of the brain, then phenomena as a whole must arise in transmutation, in a process of Becoming rather than in a state of Being, and Space must be the content, the condition, in which that process proceeds. The laws of Space, therefore, are laws, so to speak, of motion, not of position. The most absolutely still and motionless visual presentation is really a series of constant transmutations of Energy and the form of Space is constituted by the laws of transmutation, which are thus at once the necessary conditions of my perception and the universal conditions of all sense-perception. Space, therefore, does not contain the real thing which sustains the phenomenal world any more than it does the reality which underlies my conscious self. It is the universal condition of the transmutations which constitute phenomena; and it therefore "contains" all these phenomena, including my body as phenomenon and only as phenomenon. Its form is discovered by my organic motor activity, and in representing this activity the mind constructs its concepts of Space and Extension.

This view of the nature of Space, by relating its forms and laws with the objective, and a-logical thing-in-itself in virtue of the transmutations of which our sense-experience occurs, relieves an obvious difficulty which must always have been felt in accepting without qualification the purely Kantian view which regarded it as a category imposed by the Intelligence upon the otherwise unknowable world of sense.

The most ardent assertors of the ideality of Space have hitherto apparently had difficulty in avoiding the tendency to conceive it as the persistent all-embracing objective content of the thing-in-itself, not merely of the phenomenon, although the latter only might enter into Knowledge. The doctrine, however, which presents our conception of Space as discovered in our activity amid resistant transmutation-processes not only establishes its ideality but at the same time explains the relation which its form nevertheless bears to the objective material laws of the sensible presentation. It liberates the mind from the oppressive necessity of regarding Space as still somehow objectively extending and containing the real world. It also relieves an obvious difficulty which confronts the Philosophy of Schopenhauer in locating those transcendental forms of the phenomenon which are imposed a priori upon the presentation, and yet are not to be found in the pure Volition.

Of course, it must never be forgotten that my whole sentient experience consists primarily of the series of energetic transmutations occurring at that part of the energetic system which is in immediate vital relation with my consciousness. It is my experience of active exertion, of moving, speaking, etc., which gives a suggestion of the real energetic world. The transmutations of the real Energy of the world beyond my organism never enter my Consciousness. Transmutations arising beyond my body only enter the presentation by influencing the cerebral process. The luminous undulation and the sound-wave must both produce transmutation of the cerebral Energy in order to affect Consciousness. Yet the various characters of the transmitted impulses are distinguishable in the resultant cerebral transmutations. Thus I feel sensations of hardness, roughness, pain, colour, sound, etc. It is by a process of mental construction that I associate these with the forms of my exertional activity, and thus frame my conceptions of real bodies in the world around me—those which I more directly associate with the Energy subject to my Volition being conceived as representing my body. For reasons of convenience, I refer those conceptions chiefly to the co-ordinated visual presentation, and thus build up my conception of the extended world of material things. Science is possible because all transmutations of Energy take place according to definite numerical laws and ratios. The whole work of Science is to explain every phenomenon in terms of its definite transmutation of Energy. These definite numerical laws and processes are characteristic of all Energy transmutation, and thus regulate the experience of every intelligent being. It is in virtue of these that our separate systems of knowledge correspond, and that we are thus presented each with corresponding aspects of one outer world. The laws which regulate the cerebral changes that accompany sense-presentation are for me the necessary a priori laws of perception. It is because these laws operate in common in all brains that community of intercourse is possible amongst mankind. It is because of the further fact that the whole of the transmutations of Energy which constitute physical phenomena compose a numerically inter-related and regulated system that Science and rational knowledge are possible to the intellect of man. Our knowledge is what we are obliged to think and assert regarding experience; but the universality of experience is not explained merely by the common nature and general laws of Intelligence, but depends also on the generality of the laws under which the transmutations of Energy proceed.

We are now, therefore, by the aid of the doctrine of Energy, better able than before to distinguish accurately between the Ideal and the Real as contrasted elements in our experience.

My Presentment as a whole consists in the transmutation-processes—in the sensations, feelings, perceptions, images, ideas—in short, in all that is going on at the point where (I necessarily express myself in terms of spatial relations, though in this connection these are figurative) my sentience and intelligence are developed.

My whole Presentment is, therefore, in one sense subjective, or, as some would say, ideal. For me, my Presentment is the impression produced on, the condition established in, my Consciousness in virtue of what is going on at this so-called point of contact.

What we mean, therefore, by the subjectivity or ideality of the Presentment is the aspect of energetic transmutations when viewed as affecting my Consciousness in contrast with their obverse aspect when viewed as transmutations in the objective system. As my Presentment, they are all subjective or ideal, and it is in this reference that Berkeley and Hume, for instance, speak of ideas of sense, such as the colour blue, the heat of the fire, the pain of a blow. These, constituting the bulk of the Presentment, they distinguish from what Berkeley called ideas of the imagination—those stimulated or originated, or, as he said, "excited," by the intelligence itself. Whilst he contended that both classes are ideal or subjective, in respect that they are constituents of the Presentment, the latter have an additional title to subjectivity in respect of their origin, and constitute what are called "ideas" when the word is used in contra-distinction to "sensations"—such pure ideas occurring in response to a subjective impulse.

On the other hand, there is a sense in which the Presentment is, if not real, at least actual and objective.

So far as we know, Intelligence never develops except in conjunction with an organism—that is, in vital relation with physical Energy. My Presentment is constituted by the occurrence and depends upon the continuance of the transmutations or operations proceeding at the related point in the energetic system. Even pure ideas, though subjective not only in regard to aspect but in regard to their origin, are objective in respect that they also consist in an energetic transmutation.

Herein lies the germ of truth to be discovered even in the unintelligent dogmatism of those philosophers who assert the absolute Reality of my Presentment, as such—not merely its actuality. It is comparatively seldom, however, either in Science or Philosophy, that we meet a thinker prepared to go as far as that. Most take refuge in a distinction between primary and secondary qualities of bodies, classing my sensations as non-resembling secondary qualities, which they admit cannot be conceived to exist without the mind in the form in which they make up my Presentment, but reserving five or six primary qualities—solidity, extension, figure, motion, rest—which they conceive to exist independently, just as they enter into my Presentment. In point of fact, however, these so-called primary qualities are not the names of intuitions, but are abstractions or generalisations of the most general and necessary elements of my active Experience by reference to which I mentally construct my world. The transmutations of Energy are not a never-repeated accidental kaleidoscope. They proceed according to constant, definite, measurable laws, and though subordinate variations are infinite and make up the details of my Presentment, the general laws and conditions according to which all Energy transmutes are definite, and constitute the general features or qualities of my Experience, and these are the so-called primary qualities of bodies regarded in the light of the doctrine of Energy.

The primary quality of extension, in particular, is a conception resulting from the association of my visual Presentment with my power of active exertion, and the delusive tendency to regard this quality as in some sense primarily and fundamentally real is due to the unconscious recognition of the fact that it is in virtue of my power, or association as an agent with the energetic system, that I derive a suggestion of the real world beyond the phenomena which constitute my experience.

I cannot exist without some development of activity. Hence are derived my conceptions of free space and of resistance between bodies. My primary sensations are the sensations of touch, and the primary impulse of thought is to relate these with my active exertions. When sight is first restored to the blind the first impulse is to regard the new sensation as a form of touch. Its intellectual suggestiveness is a development. The system or stream of transmutations in which my volitional activity principally takes part is that represented by the operation of the forces of Gravitation and Cohesion; the system which influences my visual sensations is a quite different series. The changes in this latter series, by their greater rapidity, enable me to anticipate the other series, and for this and other reasons I employ these sensations to signalise and symbolise the transmutations proceeding in the series with which I am more immediately related as an active and "willing" agent. All transmutations, if they result in sensations, must do so by producing changes in the Energy of my organism, and must therefore be conditioned by the general laws which regulate the changes which occur there, or, in other words, must be contained within a self-consistent spatial condition; but the differences in the characters of visual Space, as it is called, and the spatial content of my activity, reflect the differences in the series of energetic transmutations with which they are respectively connected.

We see more clearly, therefore, with the aid of the doctrine of Energy, the import of the theory of transcendental aesthetic enunciated by Kant, who first pointed out that there are elements, and those the most necessary and universal, in the sense-presentation which bear the character of ideality as fully as the most subjective efforts of our ideative activity. More particularly do we illustrate the ideality of Space as a cognition precedent to experience. It is because general laws constantly operative regulate the transmutations which constitute the individual's Presentment that it is possible for him to abstract from and generalise the data of sense; and it is because the subjective process of Ideation, by which we mean our representative mental activity in its widest sense, consists also in transmutations under the same general laws of the same portion of the energetic organism, that it is possible to frame general ideas. These general laws of organic transmutation are the a priori conditions of the necessary determination in time of all existences in the world of phenomena.

The form, therefore, of the phenomenon, in the language of Kant, is constituted by the transmutations of the Energy immediately related to consciousness; the matter of the phenomenon is constituted by the varieties produced in these by the transmitted transmutations from the Energy beyond—just as the musician may produce a constant variety of harmonies upon his instrument, but all must be conditioned by the relations fixed and established between the notes of which the instrument is composed. Transmutations of the cerebral Energy may be stimulated not only from without, but by subjective impulse from within; but in either case the laws of these transmutations are the necessary form of experience, and it is the possibility of transmutation upon an internal and subjective impulse which makes possible the formation of synthetical judgments a priori. It is as if the organ were not only responsive to impressions upon its keyboard from without, but were also automotive and could originate harmonies in its own notes; and as if, moreover, it were endowed with consciousness so as to receive an intuition of both classes of music. The former would correspond to sensations, the latter to ideas; and we might imagine such an instrument by presenting to itself its own system of notes, contriving thus to frame a priori a synthetical system of these general musical laws which would constitute the necessary and universal form of its whole musical experience. To complete the perhaps fantastic analogy we must imagine the world to be one co-ordinated musical system, and our instrument to be endowed with the power of playing upon the other keyboards; of thence deriving the suggestion of the distinction between the internal and external impulses which respectively awakened harmonies within itself; and lastly, of thus at length conceiving in the spirit of science that the necessary and universal laws which it recognised as the most subjective and fundamental conditions of its own operation, at the same time regulated the activity of the entire musical universe.

How natural it would be for such an intelligent musical instrument, if unhappily endowed with common sense, to believe and assert that the real substance of the universe consisted solely of sounds. Yet how evident would it be to us from our standpoint of more absolute knowledge that the whole orchestra of sounds, although actual and quite distinct from consciousness, was still merely phenomenal, and yet withal, in its every expression, revealed the laws and structure of reality—of the system of things in themselves—a system the reality of which was dissimilar to those appearances, though all its laws and structure could be studied and derived from them.

Berkeley, therefore, erred seriously when he described the idea as a fainter sensation. Faint subjective reproductions of our sensations, as of blue, green, or the like, constitute a very insignificant element in our mental furniture. We seldom pursue so far into detail the ideative effort. Severely and effectively as Berkeley criticised Locke's account of abstract ideas, the fact remains that abstraction is a primary feature of our whole conceptual system; and the abstractable elements of the sensible presentation being the necessary constituents of all ideative representation are properly denominated ideal. The one element of particularity which every idea lacks is the reference to the transmitted transmutation to which the sensible phenomenon owes its origin. We derive such reference to the external solely from the obstructions which our free activity encounters and without which we could receive no suggestion of the non-ego, and in particular no suggestion of the dynamic element which fundamentally distinguishes things from thoughts. The empirical content of experience—the so-called secondary qualities of bodies—are often called in their subjective aspect "ideal" because the mental impression is obviously very different from the transmutation objectively regarded. But this is to confound the ideal with the subjective, which latter term is that properly applicable both to the sensible impression and to purely mental activity. The primary qualities, being the general laws or forms of organic Energy-transmutation, are in a higher sense ideal, for they are the necessary conditions under which both sense-presentation and ideative representation proceed. Whilst, therefore, as Kant maintained, they are the a priori element in perception, they at the same time constitute the laws which regulate all Energy-transmutation within our experience both organic and extra-organic.

We hold, therefore, to the Platonic doctrine that whilst, on the one hand, the sensible is only an object of thought in so far as it partakes of the intelligible, on the other hand the idea is not only a type for the individual mind, but is partaker also of the laws which penetrate the system of things. Idealism as a Philosophy, in denying the validity of any reference of the content of the Presentment to a further existence outside of the subjective experience, has induced that wider use of the term idea which applies it to the whole actuality of experience in its subjective aspect. With the advance of Philosophy we must revert to that more ancient use of the term idea which confines its extension into the realm of the perceptual to those elements of the sensible presentation which can be reproduced by the conceptual activity of the subject, and which in asserting, for instance, the ideality of Space, reminds us at the same time that Ideality implies not merely subjectivity, but the expression or representation also of some aspect of those laws which regulate the system of Reality.

But is not common sense right, after all? Do I really mean to say that tables, chairs, houses, mountains—the whole world of my Presentment, are to be regarded as shrivelled up and located in my brain, or in the energetic correlative of my brain? Is the whole Universe, as known to me or conceived by me, contained within a minute portion of itself—the brain? Now Science does say something very like this, and the logical difficulties of the position are very pressing. But they cannot be got over by attempting to revert to common sense, because to assert that all my conceived Universe is immediately perceived by me as it exists, would seem to involve a diffusion of my intelligence throughout Space which is still more inconceivable and self-contradictory. Even apart from this implication, the assumption of the Reality of the phenomenal world destroys itself. To assume the reality of so-called material particles is to lay the foundation of an argument which surely leads to the conclusion that the whole world of my consciousness is produced by and consists in motions in that certain small group of these same molecules which is assumed to make up my brain. The solution is only reached when we discover that the error lies in forgetting that the Reality which is the seat of my Presentment is itself unperceived, and that what I commonly call a body and a brain are the phenomena occurring in my Presentment, and which I associate with such real substratum. The real substratum of my Presentment is a part of the energetic Universe, which is constantly undergoing transmutations. Wherever such Energy is united, in an organism, with consciousness these transmutations, as affecting and perceived by such consciousness, constitute its Presentment or sense-experience; and aided by the constructive activity of thought expand, as it were, subjectively into a whole world of experience, as the electric current vibrating darkly along the narrow confines of the wire suddenly expands at the carbon point into the luminous undulations which light a city.

We admit, therefore, to the full the actuality and objectivity of the sensible presentation. We only deny that it is the real thing-in-itself. The latter is not discovered by sense. My energetic organism is like a well-fitting garment; I do not feel it at all. I feel only changes or transmutations taking place in it. Be not alarmed, therefore, for your common-sense world. We leave it to you intact and actual—not deducting even a single primary quality. Allowing fully for the extent to which, little suspected by you, it is a mentally constructed system, its elements are still actual and objective; they are modes of Reality; extension and the other primary qualities are qualities of these modes. Moreover, the Ego, I, myself, as Will, as a continuously identic intelligent agent, am not given to myself immediately in my Presentment, any more than is the real object. The existence of my Ego, of my cogitant self, is an inference which I am compelled to draw from the facts of my mental activity. Cogito, ergo sum. Similarly, my energetic organism is the real a-logical thing-in-itself which I am compelled to postulate in order to explain my perception of physical phenomena in the light of my physical activity; ago, ergo possum.

We must not overlook the unique position in our Presentment occupied by the visual presentation. Its universality, simultaneousness, minute accuracy, quantifiability, etc., are such that it is really to the visual Presentment that I refer all other elements in my sense-experience. I think of them with reference to it. In connection with it I mentally construct my world. I associate with some modification of the visual presentation the phenomena resultant upon the energetic activity of my own organism, and the other forces and potential Energies which that activity reveals and suggests. It is thus that I derive the compound idea of Body as consisting of Figure, Extension, and Solidity. The continued appearance in my visual presentation of the grey colour which I am now seeing is to me the sign of the continued persistence of that potential Energy in virtue of which I regard it as the appearance of a solid extended stone wall. Everything is referred to the visual presentation, and it is in reference to it that the mind works in constructing its world.

The whole theory of molecular action is a theory constructed in reference to the visual presentation—the reality of which, strangely, it seems to result in overthrowing. A born-blind man could never have invented the conception of atoms or molecules. This is well worth thinking over. The visual presentation is not really fundamental; and we must undo the inversion induced by its great convenience whereby we refer to it all the other elements of our sense-experience and conceive of our activity and our whole actual world by reference to the visible sign. It is in consequence of this reference to the visual that bodies are thought of as discrete units, so that it is difficult to conceive that the real thing in virtue of which we experience the perception of, say, a heap of stones, is truly more or less potential Energy—just as the continuous process of thought is very different from the disparate symbols of speech.

I habitually refer to the visual extended image as the primary basis of my idea of the world, or of any particular part of the world, such as my dining-room. Why? Simply because, for the reasons already noted, the sense of sight is the sense of universal reference. In principle it is the same habitual tendency which makes me associate every element of my world with its appropriate name. It is different in the case of other sensations. When I am absent from Niagara I do not, in thinking of it, primarily conceive of it as a roar of sound. I think of certain motions of mass which, if I were present, would occasion the subjective sensations of sound. But for the habitual tendency arising from the universal reference to the visible I would do the same in the case of the visual image. All I am necessitated to think is a real event—a real, physical, dynamical transmutation—proceeding quite independently of my perception or presence; and if I can only manage to realise that I must, for philosophical purposes, eliminate my reference to visual as well as to audible or other sensations, I will understand that all I am entitled to, and all I can, without hopeless contradiction, postulate as real thing existing independently of my perception, is a transmutation of Energy. This energy is imperceptible, unextended, unfigured, yet it is by no means a mere logical or mental necessity or associative tendency. On the contrary, it is very real. It sustains my every act. By an imperative mental necessity I am obliged, by inference from my experiences as an active and percipient agent, to postulate the energetic system in which I am involved, and with one particular centre in which I am organically related.

But we recall at this point that Science says she must still postulate Matter as the vehicle of Energy. But what does that mean except that the subject of her studies is the sensible presentation which itself consists of energy transmutation in part constantly changing but with relatively permanent and recurrent elements? These more permanent elements constitute what we call bodies. If the sensible presentation consisted exclusively of one continuous, unchanging phenomenon, Reason would never be stimulated, and Personality, Cause, Power would never have been postulated or conceived. But the transmutation is constantly "accelerated"—incessantly fluctuates and varies. Certain of these variations I recognise as related to my own volitional activity, and I am thus furnished with a key which enables me, by a sympathetic analogy, to attribute all the changes in my experience to various agents, each related to the other by the intervention of this system of physical Energy. Some of these I can further trace to the initiative of Volition of myself or other persons; others I can only recognise as integral parts of the vast energetic system of Nature, the stimulus of which I cannot follow further.

The reality of Matter is said to be proved by its indestructibility; but this characteristic can easily be resolved into (1) the indestructibility of Space and Extension which we have seen to be merely another name for the necessity or inevitable universality of the general laws and conditions of Energy transmutation, and (2) the indestructibility of the Energy to the transmutations of which we attribute the forces of Cohesion and Gravitation.

All vital activity is but a producing of changes in the stream of transmutation. We never do, nor in the nature of things do we ever try to, increase or diminish the quantity of the real Energy itself. We instinctively recognise the objective source of our physical power, and this has led some thinkers to suppose that the indestructibility of Matter is an a priori datum of thought. But such a belief is quite unfounded. All it amounts to is a recognition that the destruction of Matter is beyond our power—a necessary consequence of the fact that we merely act upon the transmutation-process. Many a long contest between the supporters of a priori and experiential knowledge can be set at rest by this view of the mediating functions of the energetic organism.

The reflections which we have thus briefly noted and illustrated open a wide field for inquiry. The scientific doctrine of Energy would seem to be pregnant with momentous consequences for Philosophy, and it is worth while for metaphysicians to devote to this subject the deepest and most deliberate thought. The results cannot easily be grasped by a mere cursory perusal of memoranda, in which we have only sketched a few salient aspects of the doctrine. We deprecate unwarrantable assurance, and are fully conscious of the difficulty of adequately expressing thought on such a theme; but we have not written rashly nor without good grounds for asking attention.

Science, it seems to us, postulates in Energy an a-logical, unextended, real thing-in-itself in terms of which the phenomena of Physics can be adequately and quantifiably stated. At the same time it furnishes Philosophy with a theory of the objectively real thing-in-itself which satisfied those necessities of thought by which we are constrained to interpret our sense-experience by a constant reference to a Reality beyond it—a necessity due to our association as Actors with an Energy beyond that which is the seat of our Presentment. Such a view avoids the incurable difficulties and contradictions involved in the theory of the reality of extended material substance, or in any theory, indeed, which asserts the reality—as presented—of the sensible presentation. Physical Reality thus conceived is consistently thinkable as co-existent with the thing-in-itself—be it ultimately Intelligence or Volition—of which our cognitive and conative existence is a manifestation. And such a doctrine, by explaining all phenomena as transmutations proceeding (according to the definite mathematical laws prevailing throughout the whole Universe of Energy) at that point in the system which is organically related to Consciousness, accounts at once for the apparent apriority and necessity of the qualities of Space, and at the same time for their evident universality and objectivity.

In a word, it would rather seem as if Science, unconscious of its pregnant possibilities, has not only formulated a theory which co-ordinates and unifies the entire fabric of physical knowledge, but has also at length furnished Philosophy with the key to that problem the solution of which has, in the words of Schopenhauer, been the main endeavour of philosophers for more than two centuries, namely, to separate by a correctly drawn line of cleavage the Ideal—that which belongs to our knowledge as such—from the Real, that which exists independently of us; and thus to determine the relation of each to the other.

To us it seems not strange that Philosophy should in the end be indebted to Science for this solution—nor should Science, in the hour of her greatest speculative victory, object too hastily to the assistance which the thinker, trained to the study of the process of thought, can render in clarifying and restating in its metaphysical aspects a theory which, if profoundly conceived, and formulated by men of science from Rumford and Davy to Stewart, Tait, and Kelvin, was partially anticipated by the metaphysician who conceived the world as will and idea.

We maintain, therefore, that the presentation of sense, the continuum or manifold, or what you will, consists in the transmutations of a real substance itself unextended and unperceived; that the laws of these transmutations are what constitute the geometric all-containing Space; that at a point in this real energetic system organically related to the intelligent self, the transmutations occurring there constitute the individual's sensible experience; that his mind, by also actively influencing the system at that point, can stimulate the train of transmutations which constitute his world of ideas; that the mind can discover itself as Will influencing transmutations in the organism which are transmitted through a wider, larger portion of the system; and can recognise the transmutations at the related point as influenced sometimes by its own Volition and sometimes by other agents. We seek to bring the added light of scientific theory to reconcile the conflict between the law and the fact, between the objects of reflection and the objects of sense, between the world of thought and the world of phenomena,—the problem which Plato raised and which has since been the central problem of Metaphysics. In doing so we present a doctrine which not only maintains the truth of the Ideal, and the actuality of the phenomenal, and the relative reality of both, but which proves, with all the cogency of Science, how it is that the Sensible is permeated by and made knowable only by the Ideal, by the laws of the transmutations which constitute actuality, and that, on the other hand, the Ideal only enters experience as the regulative principle of the ever-transmuting Reality.

The world consists not merely of phenomena, nor of phenomena and laws which regulate them. These are but transitional and imperfect aspects of Reality. "Our standard of Truth and Reality," says a recent writer, "moves us on towards an individual with laws of its own, and to laws which form the vital substance of a single existence." We approach such a goal in the conception of Energy—the laws of whose constant transmutations are what we call Nature.

We must distinguish Energy as Absolute Reality from such conceptions as Activity, which is its subjective aspect, or as Force, which is really the rate at which Energy is, in certain cases, transformed. Dynamics, which investigates Force, is a study of the fundamental transmutations of Energy. It postulates Energy as the Real Entity in terms of which it can frame a satisfactory theory of dynamical phenomena.

The metaphysical labours of the century which has elapsed since Kant have not been altogether in vain. The deeper thinkers are pretty nearly agreed that the Absolute is not to be identified with its appearances. How far they can bring home this view in practical form to the intelligence of man is another matter. Plato doubtless saw the truth in a sort of beatific vision, but the tide of speculation ebbed after his death, and its healing waters never inundated the deserts of mediaeval thought. The discursive weakness in which the speculation of the transcendental Philosophy seems to dissipate itself makes us fear a similar decline. Metaphysics must receive the assistance of the great speculative achievement of Physics. It must realise that Science can postulate a Reality unperceived and unqualified by the conditions of sense, but in terms of which Science can explain the whole phenomena of the sensible presentation in their objective aspect,—explain these as transmutations of Reality, proceeding in accordance with the general mathematical laws under which Reality transmutes itself.

It may be said that reason requires us to think that the Universe is a unity. Where do you embrace within Reality, in such a view of it, Intelligence, Volition, Feeling? We answer: Of course, obviously Reality, as postulated by Physics, does not contain these. But the Real Thing postulated by Physics is but one aspect of the whole, and may be, must be, merged in a higher Reality—of which phenomena, on the one hand, and Thought, Conation, Feeling on the other, are the appearances. That involves a further advance, the attainment of a higher degree of Truth which would bridge the Dualism of Thought and Existence, of Self and Not-self, of Spirit and Nature, and whilst, on the one hand, such Reality must fundamentally be a-logical, on the other hand Energy may owe its energy to Spirit.

In the dualism which we must, in experience, recognise, we notice one fundamental distinction: quantification, measurability, appear the attributes of the physical; quality, ideality, of the spiritual. The apprehension, therefore, of the doctrine of Energy should accomplish in clarity and security the abolition of the intolerable contradictions which have hitherto involved the search for Reality amid its appearances. We think it suggests the most satisfying explanation of the distinction which separates, and the principle which relates Ideality and Externality, and should obviate the almost childish efforts of transcendentalists to expound the relation of the Mind to a body which is involved in, and which is yet—for the individual—distinguished, they cannot tell us how, from the whole system of Nature.

Of course, neither Thought nor Volition, as such, can be the absolute Reality. They, like Physical Force, are but transmutations, affections, phases of Reality. Nor, again, is Energy, as a quality, a correct description of the Absolute, as such. The Absolute, as such, we cannot describe; but in studying, as Physics does, the relations of physical phenomena and stating these in terms of Reality, it conveniently gives Reality a name appropriate to its own standpoint.

Metaphysics rightly declines to be required to study special branches of Science. Nothing but grotesque absurdity ensues when this precaution is overlooked. Yet Metaphysics has hitherto thought itself the better of a little logic, and in the future it will have to grasp the scientific conception of Reality. There is nothing else for it; and, after all, it is remarkable how far the most fundamental conceptions of Metaphysics are dependent on a physical origin.

Surely it is of primary importance to realise the effect upon our conceptions of Space and Extension of the doctrine of the transmutations of Energy. Even the profoundest metaphysicians have seemingly failed to explain how Space, Matter, and Extension are related with Reality. You cannot ignore this difficulty by saying that these are the working conceptions of particular branches of Physical Science. But when you realise that physical phenomena, even the most permanent and rigid, are by scientific demonstration but transmutations of the real thing, you may then understand that Space, Body, and Extension are but the laws and conditions of the process. As appearances, and within the realm of phenomena, they seem still what they have always seemed. So much we still concede without diminution or obscurity; and at the same time we can harmonise them as they could never be harmonised before with postulated Reality.

It is the same with Time. The facts of memory would seem to imply that there is no succession in the Absolute. We are always present at all times of our life. In recollecting a past event we are contemplating no mere image, but the actual past event itself. Our chronometry depends on the annual motion of the Earth round the Sun. It has thus a purely physical basis.

We might illustrate the application of the doctrine of Energy to every department of Metaphysics. But such is not the object of the present essay. We merely desire to indicate briefly some of the many aspects of the theory, and if only we have been able to suggest a line of inquiry, the primary object of this essay has been attained.

FOOTNOTES:

[81:1] Originally printed in 1898, now revised and rewritten.

Printed by MORRISON & GIBB LIMITED, Edinburgh



BY THE SAME AUTHOR

THE DYNAMIC FOUNDATION OF KNOWLEDGE

Crown 8vo. 330 pp. 6s. net

"Mr. Philip, a thinker of considerable acuteness, expounds further the dynamic theory of knowledge which he propounded in 'Matter and Energy' and the 'Doctrine of Energy.' What we are really sensible of in the external world is mutation; but the consciousness of our own activity suggests the existence of something behind phenomena. The reality which sustains experience is found to be, in essence, power—power conceived as an energy containing within itself the principle of its own evolution; an energy constantly transmuting itself, and in its transmutations furnishing the entire presentation of sense. The universal application of this concept unifies science or the knowledge of nature; and the dynamic theory is applied by Mr. Philip to life, economics, and education." Times.

"Well written, and contains much sound analysis of perception and the like, with much that is debatable but suggestive and stimulating."—Nature.

"The argument is conducted with great ability and thoroughness, and the writer reveals a most accurate acquaintance with the results of both science and philosophy."—Glasgow Herald.

KEGAN PAUL, TRENCH, TRUeBNER, & CO., LTD. BROADWAY HOUSE, 68-74 CARTER LANE, LONDON, E.C.

THE END