UP to this point, however remote from ordinary every-day thoughts may be the region of speculation which we have been called upon to traverse, we have still kept within the limits of legitimate scientific hypothesis. Though we have ventured for a goodly distance into the unknown, we have not yet been required to abandon our base of operations in the known. Of the views presented in the preceding paper, some are wellnigh certainly established, some are probable, some have a sort of plausibility, others—to which we have refrained from giving assent—may possibly be true; but none are irretrievably beyond the jurisdiction of scientific tests. No suggestion has so far been broached which a very little further increase of our scientific knowledge may not show to be either eminently probable or eminently improbable. We have kept pretty clear of mere subjective guesses, such as men may wrangle about forever without coming to any conclusion. The theory of the nebular origin of our planetary system has come to command the assent of all persons qualified to appreciate the evidence on which it is based; and the more immediate conclusions which we have drawn from that theory are only such as are commonly drawn by astronomers and physicists. The doctrine of an intermolecular and interstellar ether is wrapped up in the well-established undulatory theory of light. Such is by no means the case with Sir William Thomson's vortex-atom theory, which to-day is in somewhat the same condition as the undulatory theory of Huyghens two centuries ago. This, however, is none the less a hypothesis truly scientific in conception, and in the speculations to which it leads us we are still sure of dealing with views that admit at least of definite expression and treatment. In other words, though our study of the visible universe has led us to the recognition of a kind of unseen world underlying the world of things that are seen, yet concerning the economy of this unseen world we have not been led to entertain any hypothesis that has not its possible justification in our experiences of visible phenomena.

We are now called upon, following in the wake of our esteemed authors, to venture on a different sort of exploration, in which we must cut loose altogether from our moorings in the world of which we have definite experience. We are invited to entertain suggestions concerning the peculiar economy of the invisible portion of the universe which we have no means of subjecting to any sort of test of probability, either experimental or deductive. These suggestions are, therefore, not to be regarded as properly scientific; but, with this word of caution, we may proceed to show what they are.

Compared with the life and death of cosmical systems which we have heretofore contemplated, the life and death of individuals of the human race may perhaps seem a small matter; yet because we are ourselves the men who live and die, the small event is of vastly greater interest to us than the grand series of events of which it is part and parcel. It is natural that we should be more interested in the ultimate fate of humanity than in the fate of a world which is of no account to us save as our present dwelling-place. Whether the human soul is to come to an end or not is to us a more important question than whether the visible universe, with its matter and energy, is to be absorbed in an invisible ether. It is indeed only because we are interested in the former question that we are so curious about the latter. If we could dissociate ourselves from the material universe, our habitat, we should probably speculate much less about its past and future. We care very little what becomes of the black ball of the earth, after all life has vanished from its surface; or, if we care at all about it, it is only because our thoughts about the career of the earth are necessarily mixed up with our thoughts about life. Hence in considering the probable ultimate destiny of the physical universe, our innermost purpose must be to know what is to become of all this rich and wonderful life of which the physical universe is the theatre. Has it all been developed, apparently at almost infinite waste of effort, only to be abolished again before it has attained to completeness, or does it contain or shelter some indestructible element which having drawn sustenance for a while from the senseless turmoil of physical phenomena shall still survive their final decay? This question is closely connected with the time-honoured question of the meaning, purpose, or tendency of the world. In the career of the world is life an end, or a means toward an end, or only an incidental phenomenon in which we can discover no meaning? Contemporary theologians seem generally to believe that one necessary result of modern scientific inquiry must be the destruction of the belief in immortal life, since against every thoroughgoing expounder of scientific knowledge they seek to hurl the charge of "materialism." Their doubts, however, are not shared by our authors, thorough men of science as they are, though their mode of dealing with the question may not be such as we can well adopt. While upholding the doctrine of evolution, and all the so-called "materialistic" views of modern science, they not only regard the hypothesis of a future life as admissible, but they even go so far as to propound a physical theory as to the nature of existence after death. Let us see what this physical theory is.

As far as the visible universe is concerned, we do not find in it any evidence of immortality or of permanence of any sort, unless it be in the sum of potential and kinetic energies on the persistency of which depends our principle of continuity. In ordinary language "the stars in their courses" serve as symbols of permanence, yet we have found reason to regard them as but temporary phenomena. So, in the language of our authors, "if we take the individual man, we find that he lives his short tale of years, and that then the visible machinery which connects him with the past, as well as that which enables him to act in the present, falls into ruin and is brought to an end. If any germ or potentiality remains, it is certainly not connected with the visible order of things." In like manner our race is pretty sure to come to an end long before the destruction of the planet from which it now gets its sustenance. And in our authors opinion even the universe will by and by become "old and effete, no less truly than the individual: it is a glorious garment this visible universe, but not an immortal one; we must look elsewhere if we are to be clothed with immortality as with a garment."

It is at this point that our authors call attention to "the apparently wasteful character of the arrangements of the visible universe." The fact is one which we have already sufficiently described, but we shall do well to quote the words in which our authors recur to it: "All but a very small portion of the sun's heat goes day by day into what we call empty space, and it is only this very small remainder that is made use of by the various planets for purposes of their own. Can anything be more perplexing than this seemingly frightful expenditure of the very life and essence of the system? That this vast store of high-class energy should be doing nothing but travelling outwards in space at the rate of 188,000 miles per second is hardly conceivable, especially when the result of it is the inevitable destruction of the visible universe."

Pursuing this teleological argument, it is suggested that perhaps this apparent waste of energy is "only an arrangement in virtue of which our universe keeps up a memory of the past at the expense of the present, inasmuch as all memory consists in an investiture of present resources in order to keep a hold upon the past." Recourse is had to the ingenious argument in which Mr. Babbage showed that "if we had power to follow and detect the minutest effects of any disturbance, each particle of existing matter must be a register of all that has happened. The track of every canoe, of every vessel that has yet disturbed the surface of the ocean, whether impelled by manual force or elemental power, remains forever registered in the future movement of all succeeding particles which may occupy its place. The furrow which is left is, indeed, instantly filled up by the closing waters; but they draw after them other and larger portions of the surrounding element, and these again, once moved, communicate motion to others in endless succession." In like manner, "the air itself is one vast library, on whose pages are forever written all that man has ever said or even whispered. There in their mutable but unerring characters, mixed with the earliest as well as the latest sighs of mortality, stand forever recorded vows unredeemed, promises unfulfilled, perpetuating in the united movements of each particle the testimony of man's changeful will." 6 In some such way as this, records of every movement that takes place in the world are each moment transmitted, with the speed of light, through the invisible ocean of ether with which the world is surrounded. Even the molecular displacements which occur in our brains when we feel and think are thus propagated in their effects into the unseen world. The world of ether is thus regarded by our authors as in some sort the obverse or complement of the world of sensible matter, so that whatever energy is dissipated in the one is by the same act accumulated in the other. It is like the negative plate in photography, where light answers to shadow and shadow to light. Or, still better, it is like the case of an equation in which whatever quantity you take from one side is added to the other with a contrary sign, while the relation of equality remains undisturbed. Thus, it will be noticed, from the ingenious and subtle, but quite defensible suggestion of Mr. Babbage, a leap is made to an assumption which cannot be defended scientifically, but only teleologically. It is one thing to say that every movement in the visible world transmits a record of itself to the surrounding ether, in such a way that from the undulation of the ether a sufficiently powerful intelligence might infer the character of the generating movement in the visible world. It is quite another thing to say that the ether is organized in such a complex and delicate way as to be like a negative image or counterpart of the world of sensible matter. The latter view is no doubt ingenious, but it is gratuitous. It is sustained not by scientific analogy, but by the desire to find some assignable use for the energy which is constantly escaping from visible matter into invisible ether. The moment we ask how do we know that this energy is not really wasted, or that it is not put to some use wholly undiscoverable by human intelligence, this assumption of an organized ether is at once seen to be groundless. It belongs not to the region of science, but to that of pure mythology.

In justice to our authors, however, it should be remembered that this assumption is put forth not as something scientifically probable, but as something which for aught we know to the contrary may possibly be true. This, to be sure, we need not deny; nor if we once allow this prodigious leap of inference, shall we find much difficulty in reaching the famous conclusion that "thought conceived to affect the matter of another universe simultaneously with this may explain a future state." This proposition, quaintly couched in an anagram, like the discoveries of old astronomers, was published last year in "Nature," as containing the gist of the forthcoming book. On the negative-image hypothesis it is not hard to see how thought is conceived to affect the seen and the unseen worlds simultaneously. Every act of consciousness is accompanied by molecular displacements in the brain, and these are of course responded to by movements in the ethereal world. Thus as a series of conscious states build up a continuous memory in strict accordance with physical laws of motion, 7 so a correlative memory is simultaneously built up in the ethereal world out of the ethereal correlatives of the molecular displacements which go on in our brains. And as there is a continual transfer of energy from the visible world to the ether, the extinction of vital energy which we call death must coincide in some way with the awakening of vital energy in the correlative world; so that the darkening of consciousness here is coincident with its dawning there. In this way death is for the individual but a transfer from one physical state of existence to another; and so, on the largest scale, the death or final loss of energy by the whole visible universe has its counterpart in the acquirement of a maximum of life by the correlative unseen world.

There seems to be a certain sort of rigorous logical consistency in this daring speculation; but really the propositions of which it consists are so far from answering to anything within the domain of human experience that we are unable to tell whether any one of them logically follows from its predecessor or not. It is evident that we are quite out of the region of scientific tests, and to whatever view our authors may urge we can only languidly assent that it is out of our power to disprove it.

The essential weakness of such a theory as this lies in the fact that it is thoroughly materialistic in character. It is currently assumed that the doctrine of a life after death cannot be defended on materialistic grounds, but this is altogether too hasty an assumption. Our authors, indeed, are not philosophical materialists, like Dr. Priestley,—who nevertheless believed in a future life,—but one of the primary doctrines of materialism lies at the bottom of their argument. Materialism holds for one thing that consciousness is a product of a peculiar organization of matter, and for another thing that consciousness cannot survive the disorganization of the material body with which it is associated. As held by philosophical materialists, like Buchner and Moleschott, these two opinions are strictly consistent with each other; nay, the latter seems to be the inevitable inference from the former, though Priestley did not so regard it. Now our authors very properly refuse to commit themselves to the opinion that mind is the product of matter, but their argument nevertheless implies that some sort of material vehicle is necessary for the continuance of mind in a future state of existence. This material vehicle they seek to supply in the theory which connects by invisible bonds of transmitted energy the perishable material body with its counterpart in the world of ether. The materialism of the argument is indeed partly veiled by the terminology in which this counterpart is called a "spiritual body," but in this novel use or abuse of scriptural language there seems to me to be a strange confusion of ideas. Bear in mind that the "invisible universe" into which energy is constantly passing is simply the luminiferous ether, which our authors, to suit the requirements of their hypothesis, have gratuitously endowed with a complexity and variety of structure analogous to that of the visible world of matter. Their language is not always quite so precise as one could desire, for while they sometimes speak of the ether itself as the "unseen universe," they sometimes allude to a primordial medium yet subtler in constitution and presumably more immaterial. Herein lies the confusion. Why should the luminiferous ether, or any primordial medium in which it may have been generated, be regarded as in any way "spiritual"? Great physicists, like less trained thinkers, are sometimes liable to be unconsciously influenced by old associations of ideas which, ostensibly repudiated, still lurk under cover of the words we use. I fear that the old associations which led the ancients to describe the soul as a breath or a shadow, and which account for the etymologies of such words as "ghost" and "spirit," have had something to do with this spiritualization of the interstellar ether. Some share may also have been contributed by the Platonic notion of the "grossness" or "bruteness" of tangible matter,—a notion which has survived in Christian theology, and which educated men of the present day have by no means universally outgrown. Save for some such old associations as these, why should it be supposed that matter becomes "spriritualized" as it diminishes in apparent substantiality? Why should matter be pronounced respectable in the inverse ratio of its density or ponderability? Why is a diamond any more chargeable with "grossness" than a cubic centimetre of hydrogen? Obviously such fancies are purely of mythologic parentage. Now the luminiferous ether, upon which our authors make such extensive demands, may be physically "ethereal" enough, in spite of the enormous elasticity which leads Professor Jevons to characterize it as "adamantine"; but most assuredly we have not the slightest reason for speaking of it as "immaterial" or "spiritual." Though we are unable to weigh it in the balance, we at least know it as a transmitter of undulatory movements, the size and shape of which we can accurately measure. Its force-relations with ponderable matter are not only universally and incessantly maintained, but they have that precisely quantitative character which implies an essential identity between the innermost natures of the two substances. We have seen reason for thinking it probable that ether and ordinary matter are alike composed of vortex-rings in a quasi-frictionless fluid; but whatever be the fate of this subtle hypothesis, we may be sure that no theory will ever be entertained in which the analysis of ether shall require different symbols from that of ordinary matter. In our authors' theory, therefore, the putting on of immortality is in no wise the passage from a material to a spiritual state. It is the passage from one kind of materially conditioned state to another. The theory thus appeals directly to our experiences of the behaviour of matter; and in deriving so little support as it does from these experiences, it remains an essentially weak speculation, whatever we may think of its ingenuity. For so long as we are asked to accept conclusions drawn from our experiences of the material world, we are justified in demanding something more than mere unconditioned possibility. We require some positive evidence, be it ever so little in amount; and no theory which cannot furnish such positive evidence is likely to carry to our minds much practical conviction.

This is what I meant by saying that the great weakness of the hypothesis here criticized lies in its materialistic character. In contrast with this we shall presently see that the assertion of a future life which is not materially conditioned, though unsupported by any item of experience whatever, may nevertheless be an impregnable assertion. But first I would conclude the foregoing criticism by ruling out altogether the sense in which our authors use the expression "Unseen Universe." Scientific inference, however remote, is connected by such insensible gradations with ordinary perception, that one may well question the propriety of applying the term "unseen" to that which is presented to "the mind's eye" as inevitable matter of inference. It is true that we cannot see the ocean of ether in which visible matter floats; but there are many other invisible things which yet we do not regard as part of the "unseen world." I do not see the air which I am now breathing within the four walls of my study, yet its existence is sufficiently a matter of sense-perception as it fills my lungs and fans my cheek. The atoms which compose a drop of water are not only invisible, but cannot in any way be made the objects of sense-perception; yet by proper inferences from their behaviour we can single them out for measurement, so that Sir William Thomson can tell us that if the drop of water were magnified to the size of the earth, the constituent atoms would be larger than peas, but not so large as billiard-balls. If we do not see such atoms with our eyes, we have one adequate reason in their tiny dimensions, though there are further reasons than this. It would be hard to say why the luminiferous ether should be relegated to the "unseen world" any more than the material atom. Whatever we know as possessing resistance and extension, whatever we can subject to mathematical processes of measurement, we also conceive as existing in such shape that, with appropriate eyes and under proper visual conditions, we MIGHT see it, and we are not entitled to draw any line of demarcation between such an object of inference and others which may be made objects of sense-perception. To set apart the ether as constituting an "unseen universe" is therefore illegitimate and confusing. It introduces a distinction where there is none, and obscures the fact that both invisible ether and visible matter form but one grand universe in which the sum of energy remains constant, though the order of its distribution endlessly varies.

Very different would be the logical position of a theory which should assume the existence of an "Unseen World" entirely spiritual in constitution, and in which material conditions like those of the visible world should have neither place nor meaning. Such a world would not consist of ethers or gases or ghosts, but of purely psychical relations akin to such as constitute thoughts and feelings when our minds are least solicited by sense-perceptions. In thus marking off the "Unseen World" from the objective universe of which we have knowledge, our line of demarcation would at least be drawn in the right place. The distinction between psychical and material phenomena is a distinction of a different order from all other distinctions known to philosophy, and it immeasurably transcends all others. The progress of modern discovery has in no respect weakened the force of Descartes's remark, that between that of which the differential attribute is Thought and that of which the differential attribute is Extension, there can be no similarity, no community of nature whatever. By no scientific cunning of experiment or deduction can Thought be weighed or measured or in any way assimilated to such things as may be made the actual or possible objects of sense-perception. Modern discovery, so far from bridging over the chasm between Mind and Matter, tends rather to exhibit the distinction between them as absolute. It has, indeed, been rendered highly probable that every act of consciousness is accompanied by a molecular motion in the cells and fibres of the brain; and materialists have found great comfort in this fact, while theologians and persons of little faith have been very much frightened by it. But since no one ever pretended that thought can go on, under the conditions of the present life, without a brain, one finds it rather hard to sympathize either with the self-congratulations of Dr. Buchner's disciples 8 or with the terrors of their opponents. But what has been less commonly remarked is the fact that when the thought and the molecular movement thus occur simultaneously, in no scientific sense is the thought the product of the molecular movement. The sun-derived energy of motion latent in the food we eat is variously transformed within the organism, until some of it appears as the motion of the molecules of a little globule of nerve-matter in the brain. In a rough way we might thus say that the chemical energy of the food indirectly produces the motion of these little nerve-molecules. But does this motion of nerve-molecules now produce a thought or state of consciousness? By no means. It simply produces some other motion of nerve-molecules, and this in turn produces motion of contraction or expansion in some muscle, or becomes transformed into the chemical energy of some secreting gland. At no point in the whole circuit does a unit of motion disappear as motion to reappear as a unit of consciousness. The physical process is complete in itself, and the thought does not enter into it. All that we can say is, that the occurrence of the thought is simultaneous with that part of the physical process which consists of a molecular movement in the brain. 9 To be sure, the thought is always there when summoned, but it stands outside the dynamic circuit, as something utterly alien from and incomparable with the events which summon it. No doubt, as Professor Tyndall observes, if we knew exhaustively the physical state of the brain, "the corresponding thought or feeling might be inferred; or, given the thought or feeling, the corresponding state of the brain might be inferred. But how inferred? It would be at bottom not a case of logical inference at all, but of empirical association. You may reply that many of the inferences of science are of this character; the inference, for example, that an electric current of a given direction will deflect a magnetic needle in a definite way; but the cases differ in this, that the passage from the current to the needle, if not demonstrable, is thinkable, and that we entertain no doubt as to the final mechanical solution of the problem. But the passage from the physics of the brain to the corresponding facts of consciousness is unthinkable. Granted that a definite thought and a definite molecular action in the brain occur simultaneously; we do not possess the intellectual organ, nor apparently any rudiment of the organ, which would enable us to pass by a process of reasoning from the one to the other. They appear together, but we do not know why." 10

An unseen world consisting of purely psychical or spiritual phenomena would accordingly be demarcated by an absolute gulf from what we call the material universe, but would not necessarily be discontinuous with the psychical phenomena which we find manifested in connection with the world of matter. The transfer of matter, or physical energy, or anything else that is quantitatively measurable, into such an unseen world, may be set down as impossible, by reason of the very definition of such a world. Any hypothesis which should assume such a transfer would involve a contradiction in terms. But the hypothesis of a survival of present psychical phenomena in such a world, after being denuded of material conditions, is not in itself absurd or self-contradictory, though it may be impossible to support it by any arguments drawn from the domain of human experience. Such is the shape which it seems to me that, in the present state of philosophy, the hypothesis of a future life must assume. We have nothing to say to gross materialistic notions of ghosts and bogies, and spirits that upset tables and whisper to ignorant vulgar women the wonderful information that you once had an aunt Susan. The unseen world imagined in our hypothesis is not connected with the present material universe by any such "invisible bonds" as would allow Bacon and Addison to come to Boston and write the silliest twaddle in the most ungrammatical English before a roomful of people who have never learned how to test what they are pleased to call the "evidence of their senses." Our hypothesis is expressly framed so as to exclude all intercourse whatever between the unseen world of spirit unconditioned by matter and the present world of spirit conditioned by matter in which all our experiences have been gathered. The hypothesis being framed in such a way, the question is, What has philosophy to say to it? Can we, by searching our experiences, find any reason for adopting such an hypothesis? Or, on the other hand, supposing we can find no such reason, would the total failure of experimental evidence justify us in rejecting it?

The question is so important that I will restate it. I have imagined a world made up of psychical phenomena, freed from the material conditions under which alone we know such phenomena. Can we adduce any proof of the possibility of such a world? Or if we cannot, does our failure raise the slightest presumption that such a world is impossible?

The reply to the first clause of the question is sufficiently obvious. We have no experience whatever of psychical phenomena save as manifested in connection with material phenomena. We know of Mind only as a group of activities which are never exhibited to us except through the medium of motions of matter. In all our experience we have never encountered such activities save in connection with certain very complicated groupings of highly mobile material particles into aggregates which we call living organisms. And we have never found them manifested to a very conspicuous extent save in connection with some of those specially organized aggregates which have vertebrate skeletons and mammary glands. Nay, more, when we survey the net results of our experience up to the present time, we find indisputable evidence that in the past history of the visible universe psychical phenomena have only begun to be manifested in connection with certain complex aggregates of material phenomena. As these material aggregates have age by age become more complex in structure, more complex psychical phenomena have been exhibited. The development of Mind has from the outset been associated with the development of Matter. And to-day, though none of us has any knowledge of the end of psychical phenomena in his own case, yet from all the marks by which we recognize such phenomena in our fellow-creatures, whether brute or human, we are taught that when certain material processes have been gradually or suddenly brought to an end, psychical phenomena are no longer manifested. From first to last, therefore, our appeal to experience gets but one response. We have not the faintest shadow of evidence wherewith to make it seem probable that Mind can exist except in connection with a material body. Viewed from this standpoint of terrestrial experience, there is no more reason for supposing that consciousness survives the dissolution of the brain than for supposing that the pungent flavour of table-salt survives its decomposition into metallic sodium and gaseous chlorine.

Our answer from this side is thus unequivocal enough. Indeed, so uniform has been the teaching of experience in this respect that even in their attempts to depict a life after death, men have always found themselves obliged to have recourse to materialistic symbols. To the mind of a savage the future world is a mere reproduction of the present, with its everlasting huntings and fightings. The early Christians looked forward to a renovation of the earth and the bodily resurrection from Sheol of the righteous. The pictures of hell and purgatory, and even of paradise, in Dante's great poem, are so intensely materialistic as to seem grotesque in this more spiritual age. But even to-day the popular conceptions of heaven are by no means freed from the notion of matter; and persons of high culture, who realize the inadequacy of these popular conceptions, are wont to avoid the difficulty by refraining from putting their hopes and beliefs into any definite or describable form. Not unfrequently one sees a smile raised at the assumption of knowledge or insight by preachers who describe in eloquent terms the joys of a future state; yet the smile does not necessarily imply any scepticism as to the abstract probability of the soul's survival. The scepticism is aimed at the character of the description rather than at the reality of the thing described. It implies a tacit agreement, among cultivated people, that the unseen world must be purely spiritual in constitution. The agreement is not habitually expressed in definite formulas, for the reason that no mental image of a purely spiritual world can be formed. Much stress is commonly laid upon the recognition of friends in a future life; and however deep a meaning may be given to the phrase "the love of God," one does not easily realize that a heavenly existence could be worth the longing that is felt for it, if it were to afford no further scope for the pure and tender household affections which give to the present life its powerful though indefinable charm. Yet the recognition of friends in a purely spiritual world is something of which we can frame no conception whatever. We may look with unspeakable reverence on the features of wife or child, less because of their physical beauty than because of the beauty of soul to which they give expression, but to imagine the perception of soul by soul apart from the material structure and activities in which soul is manifested, is something utterly beyond our power. Nay, even when we try to represent to ourselves the psychical activity of any single soul by itself as continuing without the aid of the physical machinery of sensation, we get into unmanageable difficulties. A great part of the contents of our minds consists of sensuous (chiefly visual) images, and though we may imagine reflection to go on without further images supplied by vision or hearing, touch or taste or smell, yet we cannot well see how fresh experiences could be gained in such a state. The reader, if he require further illustrations, can easily follow out this line of thought. Enough has no doubt been said to convince him that our hypothesis of the survival of conscious activity apart from material conditions is not only utterly unsupported by any evidence that can be gathered from the world of which we have experience, but is utterly and hopelessly inconceivable.

It is inconceivable BECAUSE it is entirely without foundation in experience. Our powers of conception are closely determined by the limits of our experience. When a proposition, or combination of ideas, is suggested, for which there has never been any precedent in human experience, we find it to be UNTHINKABLE,—the ideas will not combine. The proposition remains one which we may utter and defend, and perhaps vituperate our neighbours for not accepting, but it remains none the less an unthinkable proposition. It takes terms which severally have meanings and puts them together into a phrase which has no meaning. 11 Now when we try to combine the idea of the continuance of conscious activity with the idea of the entire cessation of material conditions, and thereby to assert the existence of a purely spiritual world, we find that we have made an unthinkable proposition. We may defend our hypothesis as passionately as we like, but when we strive coolly to realize it in thought we find ourselves baulked at every step.

But now we have to ask, How much does this inconceivability signify? In most cases, when we say that a statement is inconceivable, we practically declare it to be untrue; when we say that a statement is without warrant in experience, we plainly indicate that we consider it unworthy of our acceptance. This is legitimate in the majority of cases with which we have to deal in the course of life, because experience, and the capacities of thought called out and limited by experience, are our only guides in the conduct of life. But every one will admit that our experience is not infinite, and that our capacity of conception is not coextensive with the possibilities of existence. It is not only possible, but in the very highest degree probable, that there are many things in heaven, if not on earth, which are undreamed of in our philosophy. Since our ability to conceive anything is limited by the extent of our experience, and since human experience is very far from being infinite, it follows that there may be, and in all probability is, an immense region of existence in every way as real as the region which we know, yet concerning which we cannot form the faintest rudiment of a conception. Any hypothesis relating to such a region of existence is not only not disproved by the total failure of evidence in its favour, but the total failure of evidence does not raise even the slightest prima facie presumption against its validity.

These considerations apply with great force to the hypothesis of an unseen world in which psychical phenomena persist in the absence of material conditions. It is true, on the one hand, that we can bring up no scientific evidence in support of such an hypothesis. But on the other hand it is equally true that in the very nature of things no such evidence could be expected to be forthcoming: even were there such evidence in abundance, it could not be accessible to us. The existence of a single soul, or congeries of psychical phenomena, unaccompanied by a material body, would be evidence sufficient to demonstrate the hypothesis. But in the nature of things, even were there a million such souls round about us, we could not become aware of the existence of one of them, for we have no organ or faculty for the perception of soul apart from the material structure and activities in which it has been manifested throughout the whole course of our experience. Even our own self-consciousness involves the consciousness of ourselves as partly material bodies. These considerations show that our hypothesis is very different from the ordinary hypotheses with which science deals. The entire absence of testimony does not raise a negative presumption except in cases where testimony is accessible. In the hypotheses with which scientific men are occupied, testimony is always accessible; and if we do not find any, the presumption is raised that there is none. When Dr. Bastian tells us that he has found living organisms to be generated in sealed flasks from which all living germs had been excluded, we demand the evidence for his assertion. The testimony of facts is in this case hard to elicit, and only skilful reasoners can properly estimate its worth. But still it is all accessible. With more or less labour it can be got at; and if we find that Dr. Bastian has produced no evidence save such as may equally well receive a different interpretation from that which he has given it, we rightly feel that a strong presumption has been raised against his hypothesis. It is a case in which we are entitled to expect to find the favouring facts if there are any, and so long as we do not find such, we are justified in doubting their existence. So when our authors propound the hypothesis of an unseen universe consisting of phenomena which occur in the interstellar ether, or even in some primordial fluid with which the ether has physical relations, we are entitled to demand their proofs. It is not enough to tell us that we cannot disprove such a theory. The burden of proof lies with them. The interstellar ether is something concerning the physical properties of which we have some knowledge; and surely, if all the things are going on which they suppose in a medium so closely related to ordinary matter, there ought to be some traceable indications of the fact. At least, until the contrary can be shown, we must refuse to believe that all the testimony in a case like this is utterly inaccessible; and accordingly, so long as none is found, especially so long as none is even alleged, we feel that a presumption is raised against their theory.

These illustrations will show, by sheer contrast, how different it is with the hypothesis of an unseen world that is purely spiritual. The testimony in such a case must, under the conditions of the present life, be forever inaccessible. It lies wholly outside the range of experience. However abundant it may be, we cannot expect to meet with it. And accordingly our failure to produce it does not raise even the slightest presumption against our theory. When conceived in this way, the belief in a future life is without scientific support; but at the same time it is placed beyond the need of scientific support and beyond the range of scientific criticism. It is a belief which no imaginable future advance in physical discovery can in any way impugn. It is a belief which is in no sense irrational, and which may be logically entertained without in the least affecting our scientific habit of mind or influencing our scientific conclusions.

To take a brief illustration: we have alluded to the fact that in the history of our present world the development of mental phenomena has gone on hand in hand with the development of organic life, while at the same time we have found it impossible to explain mental phenomena as in any sense the product of material phenomena. Now there is another side to all this. The great lesson which Berkeley taught mankind was that what we call material phenomena are really the products of consciousness co-operating with some Unknown Power (not material) existing beyond consciousness. We do very well to speak of "matter" in common parlance, but all that the word really means is a group of qualities which have no existence apart from our minds. Modern philosophers have quite generally accepted this conclusion, and every attempt to overturn Berkeley's reasoning has hitherto resulted in complete and disastrous failure. In admitting this, we do not admit the conclusion of Absolute Idealism, that nothing exists outside of consciousness. What we admit as existing independently of our own consciousness is the Power that causes in us those conscious states which we call the perception of material qualities. We have no reason for regarding this Power as in itself material: indeed, we cannot do so, since by the theory material qualities have no existence apart from our minds. I have elsewhere sought to show that less difficulty is involved in regarding this Power outside of us as quasi-psychical, or in some measure similar to the mental part of ourselves; and I have gone on to conclude that this Power may be identical with what men have, in all times and by the aid of various imperfect symbols, endeavoured to apprehend as Deity. 12 We are thus led to a view of things not very unlike the views entertained by Spinoza and Berkeley. We are led to the inference that what we call the material universe is but the manifestation of infinite Deity to our finite minds. Obviously, on this view, Matter—the only thing to which materialists concede real existence—is simply an orderly phantasmagoria; and God and the Soul—which materialists regard as mere fictions of the imagination—are the only conceptions that answer to real existences.

In the foregoing paragraph I have been setting down opinions with which I am prepared to agree, and which are not in conflict with anything that our study of the development of the objective world has taught us. In so far as that study may be supposed to bear on the question of a future life, two conclusions are open to us. First we may say that since the phenomena of mind appear and run their course along with certain specialized groups of material phenomena, so, too, they must disappear when these specialized groups are broken up. Or, in other words, we may say that every living person is an organized whole; consciousness is something which pertains to this organized whole, as music belongs to the harp that is entire; but when the harp is broken it is silent, and when the organized whole of personality falls to pieces consciousness ceases forever. To many well-disciplined minds this conclusion seems irresistible; and doubtless it would be a sound one—a good Baconian conclusion—if we were to admit, with the materialists, that the possibilities of existence are limited by our tiny and ephemeral experience.

But now, supposing some Platonic speculator were to come along and insist upon our leaving room for an alternative conclusion; suppose he were to urge upon us that all this process of material development, with the discovery of which our patient study has been rewarded, may be but the temporary manifestation of relations otherwise unknown between ourselves and the infinite Deity; suppose he were to argue that psychical qualities may be inherent in a spiritual substance which under certain conditions becomes incarnated in matter, to wear it as a perishable garment for a brief season, but presently to cast it off and enter upon the freedom of a larger existence;—what reply should we be bound to make, bearing in mind that the possibilities of existence are in no wise limited by our experience? Obviously we should be bound to admit that in sound philosophy this conclusion is just as likely to be true as the other. We should, indeed, warn him not to call on us to help him to establish it by scientific arguments; and we should remind him that he must not make illicit use of his extra-experiential hypotheses by bringing them into the treatment of scientific questions that lie within the range of experience. In science, for example, we make no use of the conception of a "spiritual substance" (or of a "material substance" either), because we can get along sufficiently well by dealing solely with qualities. But with this general understanding we should feel bound to concede the impregnableness of his main position.

I have supposed this theory only as an illustration, not as a theory which I am prepared to adopt. My present purpose is not to treat as an advocate the question of a future life, but to endeavour to point out what conditions should be observed in treating the question philosophically. It seems to me that a great deal is gained when we have distinctly set before us what are the peculiar conditions of proof in the case of such transcendental questions. We have gained a great deal when we have learned how thoroughly impotent, how truly irrelevant, is physical investigation in the presence of such a question. If we get not much positive satisfaction for our unquiet yearnings, we occupy at any rate a sounder philosophic position when we recognize the limits within which our conclusions, whether positive or negative, are valid.

It seems not improbable that Mr. Mill may have had in mind something like the foregoing considerations when he suggested that there is no reason why one should not entertain the belief in a future life if the belief be necessary to one's spiritual comfort. Perhaps no suggestion in Mr. Mill's richly suggestive posthumous work has been more generally condemned as unphilosophical, on the ground that in matters of belief we must be guided, not by our likes and dislikes, but by the evidence that is accessible. The objection is certainly a sound one so far as it relates to scientific questions where evidence is accessible. To hesitate to adopt a well-supported theory because of some vague preference for a different view is in scientific matters the one unpardonable sin,—a sin which has been only too often committed. Even in matters which lie beyond the range of experience, where evidence is inaccessible, desire is not to be regarded as by itself an adequate basis for belief. But it seems to me that Mr. Mill showed a deeper knowledge of the limitations of scientific method than his critics, when he thus hinted at the possibility of entertaining a belief not amenable to scientific tests. The hypothesis of a purely spiritual unseen world, as above described, is entirely removed from the jurisdiction of physical inquiry, and can only be judged on general considerations of what has been called "moral probability"; and considerations of this sort are likely, in the future as in the past, to possess different values for different minds. He who, on such considerations, entertains a belief in a future life may not demand that his sceptical neighbour shall be convinced by the same considerations; but his neighbour is at the same time estopped from stigmatizing his belief as unphilosophical.

The consideration which must influence most minds in their attitude toward this question, is the craving, almost universally felt, for some teleological solution to the problem of existence. Why we are here now is a question of even profounder interest than whether we are to live hereafter. Unfortunately its solution carries us no less completely beyond the range of experience! The belief that all things are working together for some good end is the most essential expression of religious faith: of all intellectual propositions it is the one most closely related to that emotional yearning for a higher and better life which is the sum and substance of religion. Yet all the treatises on natural theology that have ever been written have barely succeeded in establishing a low degree of scientific probability for this belief. In spite of the eight Bridgewater Treatises, and the "Ninth" beside, dysteleology still holds full half the field as against teleology. Most of this difficulty, however, results from the crude anthropomorphic views which theologians have held concerning God. Once admitting that the Divine attributes may be (as they must be) incommensurably greater than human attributes, our faith that all things are working together for good may remain unimpugned.

To many minds such a faith will seem incompatible with belief in the ultimate destruction of sentiency amid the general doom of the material universe. A good end can have no meaning to us save in relation to consciousness that distinguishes and knows the good from the evil. There could be no better illustration of how we are hemmed in than the very inadequacy of the words with which we try to discuss this subject. Such words have all gained their meanings from human experience, and hence of necessity carry anthropomorphic implications. But we cannot help this. We must think with the symbols with which experience has furnished us; and when we so think, there does seem to be little that is even intellectually satisfying in the awful picture which science shows us, of giant worlds concentrating out of nebulous vapour, developing with prodigious waste of energy into theatres of all that is grand and sacred in spiritual endeavour, clashing and exploding again into dead vapour-balls, only to renew the same toilful process without end,—a senseless bubble-play of Titan forces, with life, love, and aspiration brought forth only to be extinguished. The human mind, however "scientific" its training, must often recoil from the conclusion that this is all; and there are moments when one passionately feels that this cannot be all. On warm June mornings in green country lanes, with sweet pine-odours wafted in the breeze which sighs through the branches, and cloud-shadows flitting over far-off blue mountains, while little birds sing their love-songs, and golden-haired children weave garlands of wild roses; or when in the solemn twilight we listen to wondrous harmonies of Beethoven and Chopin that stir the heart like voices from an unseen world; at such times one feels that the profoundest answer which science can give to our questionings is but a superficial answer after all. At these moments, when the world seems fullest of beauty, one feels most strongly that it is but the harbinger of something else,—that the ceaseless play of phenomena is no mere sport of Titans, but an orderly scene, with its reason for existing, its

Difficult as it is to disentangle the elements of reasoning that enter into these complex groups of feeling, one may still see, I think, that it is speculative interest in the world, rather than anxious interest in self, that predominates. The desire for immortality in its lowest phase is merely the outcome of the repugnance we feel toward thinking of the final cessation of vigorous vital activity. Such a feeling is naturally strong with healthy people. But in the mood which I have above tried to depict, this feeling, or any other which is merely self-regarding, is lost sight of in the feeling which associates a future life with some solution of the burdensome problem of existence. Had we but faith enough to lighten the burden of this problem, the inferior question would perhaps be less absorbing. Could we but know that our present lives are working together toward some good end, even an end in no wise anthropomorphic, it would be of less consequence whether we were individually to endure. To the dog under the knife of the experimenter, the world is a world of pure evil; yet could the poor beast but understand the alleviation of human suffering to which he is contributing, he would be forced to own that this is not quite true; and if he were also a heroic or Christian dog, the thought would perhaps take away from death its sting. The analogy may be a crude one; but the reasonableness of the universe is at least as far above our comprehension as the purposes of man surpass the understanding of the dog. Believing, however, though as a simple act of trust, that the end will crown the work, we may rise superior to the question which has here concerned us, and exclaim, in the supreme language of faith, "Though He slay me, yet will I trust in Him!"