faced unity—would appear to comply with all the exigencies of the case.” Such thinkers are not seeking to bridge over a supposed chasm between mind and matter, but are denying that there exists any gulf to be crossed. To those, on the other hand, who hold that the antithesis between mind and matter is indestructible, every attempt to identify the spheres of Subject and Object, the External and Internal worlds, must needs appear a futile undertaking. In the view of Dualistic Philosophy, the two spheres are separate as regards, alike, the essential nature of their contents, and the organs and modes of observation whereby they become known to us. Our knowledge of mind is derived from self-consciousness; our knowledge of matter from perceptive observation of the external world. Whilst the phenomena of matter are referred by us to Time and Space, mental phenomena are referred to Time alone; nor can the attempt be made to attribute extension to any purely mental experience without violating the conditions of thought, and lapsing into nonsense. Finally, whilst Mind appears essentially active, and mental experience is the source of our ideas of cause and force, the conception of Matter, of necessity, includes the notion of inertia.

The Monistic theorists of the present day affect, and no doubt desire, to take a firm and indifferent position on the fulcrum of the balance; but they fail—so at least it seems to their critics—to secure a truly central stand-point, and thus come sliding gently down the beam into the scale of Matter. Berkeley, who is followed by Mr. Frankland through the earlier portion of his paper, whilst he denied to us any knowledge of the external world of matter, affirmed (as a fact known to us more surely and intimately than any other) the existence of Mind. Hume went beyond Berkeley, denying to human knowledge the existence of both entities. He is to be considered as the immediate progenitor of the modern Phenomenal School. The modern Monist may seem to follow Berkeley for a time, but it is soon evident that minds trained in the school of physical research cannot endure a lengthened sojourn in the thin region of Idealism. It may have seemed that they were on the point of merging Matter in Mind. But, habit and training are strong with them. Their pretension to apply to mental phenomena the methods of analysis and computation which have served them in the field of Matter, makes it evident that their speculation has resulted—according to their own apprehension of its consequences—not in the resolution of Matter into Mind, but in the merging of Mind in Matter.

That this is really Mr. Frankland's position seems apparent from his very choice of a name for his doctrine. It would be difficult to find a term more thoroughly materialistic in its associations and suggestions than this of “Mind-Stuff.” If there could be any doubt about the writer's real

tendency, it is removed by the proposal to transfer to the description and investigation of mental phenomena such notions as “mass,” “motion,” “velocity,” “momentum.” To me, I confess, the proposal appears destitute of possible meaning. The notion of extension is obviously involved in every one of these terms. In our “matter-moulded forms of speech” all these ideas are applied metaphorically to spiritual existence, and the things of the pure intellect. But we are conscious of the metaphor. We speak of a massive intellect; but would not gravely affirm that Cuvier's understanding weighed precisely 64 ozs. Because we talk of “a rapid intuition,” we do not suppose ourselves able to compute, in terms of space as well as time, the speed of those glances of the mind compared with which “the tempest itself lags behind, and the swift-winged arrows of light.” The Materializing School, in treating of the emotions, in which our bodily frame co-operates with our mental constitution, often make use, with marked predilection, of language properly applicable only in the field of Physics,—and we hear continually of “waves,” “currents,” “vibrations,” and the like. But into the proper region of the intellect they do not venture on importing the idea of space. Professor Bain, in his “Compendium of Mental and Moral Science,” recognizes, in limine, the grand division of human knowledge into the two departments of Matter and Mind,—or, as he prefers to call them, Object and Subject. “The department of the Object, or Object-world, is,” he says, “exactly circumscribed by one property, extension. The world of Subject-experience is devoid of this property.”

Mr. Frankland adduces the sensation of general weariness as an instance of a mental phenomenon, involving the perception of volume or massiveness; which includes the idea of extension. But this is a physical sensation, and no instance of a purely mental experience. Our own limbs and body are as much a portion of the external world as any other part of it. Unquestionably the sense of weariness is always, more or less, definite in extent. We may feel our legs tired, or our arms, and back, or tired all over. Just in the same way we recognize in sensation, more or less exactly, the extent of a wound or burn. To prove what is wanted, an instance must be found of a purely mental emotion or operation, unconnected with any corporeal feeling. But we are certainly not conscious of the extent in square surface, or cubic space, of our love, hatred, remorse, regret; or of any process or result of the reasoning power. To these, terms of intension, which are dynamical, not material, may be applied; but never terms of extension.

But I pass on to consider the validity of the induction—shall I call it, or the fidelity of the intuition—upon which the new doctrine is to be

founded. It is made upon the collation of the mental phenomena revealed to us by self-consciousness, with those physical changes in the grey nervous matter of the brain, which are, with great probability, assumed to accompany the mental phenomena. Let it be supposed that the observer voluntarily enters upon some train of thought—say, the asses' bridge in Euclid: it is assumed, and, I concede, with great probability assumed, that this mental process will be exactly represented by concomitant observable physical changes in the nervous substance. One may imagine observations of this kind brought to a high pitch of accuracy, so that any witness of the cerebral phenomena, in the case supposed, should be enabled to infer therefrom, with certainty, that the subject was in the act of demonstrating Proposition No. 5 of the First Book. In this and similar cases Mind takes—or seems to take—the initiative. We should, therefore, expect to find the thought slightly in advance, in point of time, of its material expression; or, at least, not posterior in point of time. In such a case Mr. Frankland seems to consider himself justified in inferring that the mental operations—the noumena, as he terms them—“underlie,” or are even identical with, the physical appearances. These are his words:—“According to the doctrine of Mind-Stuff, these feelings, or thoughts [in the mind of the person to whom the brain belongs], are the noumena—the “things-in-themselves”—which underlie the changes in the grey matter of the brain. What appears to an outside observer—or rather, what would appear to him were the skull transparent, as a change in the grey matter of the brain—is, in reality, a feeling or thought in the mind of the person to whom the brain belongs.”

I find it not easy exactly to define my own position with reference to this speculation. There is much in Mr. Frankland's essay with which I heartily concur. He appears to me, if I may venture to say so, on the verge of truths which will lead him in a philosophical direction diametrically opposite to that which I understand him to be now pursuing. To such positions as these—that there are realities which underlie appearances—that physical science can never reveal to us these realities—that Psychology alone can give us philosophical access to them—I assent ex animo. But I find it necessary to question the particular mode in which the writer proposes to make the transit from that which appears to that which is.

In collating the sequence of ideas in the mind with the concomitant medullary changes, we have, I submit, two parallel series of phenomena between which we are incompetent to conceive of any necessary connection. I presume that this will be at once admitted as true in regard to any two parallel series of physical phenomena. In the field of physical science we know only, that events follow one another in an invariable sequence. We are not entitled to affirm that the antecedent event causes, or produces, the

consequent. Our knowledge is limited to the fact that the phenomena always follow one another in the same order. The phenomenal philosophy disclaims cognition of producing causes. Its so-called causes are merely invariable antecedents destitute of originating power. It is needless to enforce this doctrine upon minds trained in the philosophy of Hume, the two Mills, Auguste Comte, Bain, and Herbert Spencer. A philosophy which limits knowledge to phenomena, cannot consistently admit any other opinion. But I am not employing their doctrine as a mere argumentum ad hominem. In the field of Physics, it is, I believe, an absolute truth.

In the case we have to consider, one of the two co-ordinated series of events is physical, and the other mental; one is within, the other beyond, the sphere of consciousness. Does this make it easier to supply a connection between them? It may be argued that the sense of spontaneity, or mental initiative, in the case of a train of thought voluntarily entered upon, entitles us to regard the “noumena” as underlying the “phenomena.” That important inferences may be founded upon this sense of a mental initiative I certainly hold, but not the inference which Mr. Frankland suggests to us. His term “underlying” is somewhat equivocal. I do not think it can be understood in any way which will justify his doctrine of “Mind-Stuff.” If, by the use of the term “underlying,” it is meant to affirm that we are conscious that the mental processes cause the material—cause i.e. in the sense of producing them—I reply that we have no such consciousness. The cerebral phenomena are outside the field of consciousness; the mental outside the field of bodily vision. How shall we connect experiences which belong to different spheres and are made known by faculties of different order? We can do no more than note down the succession in time of each series, and mark their correspondence. Our experience, just as in the case of two parallel series of physical events, does not entitle us to affirm more than the invariable concomitance of the corresponding terms in the two series. The fact that the mental phenomena occur within the sphere of consciousness is no help to us. We cannot annex to them, still less identify with them, the series of physical manifestations. The changes in the nervous matter are wholly involuntary, have only recently been ascertained to exist, and remain to this hour unknown to and unsuspected by the mass of mankind. Psychology ignores them; and could we, as suggested, by some mechanical expedient be witnesses of their occurrence in our own frames, we should look upon them as something extraneous to ourselves. Their association with our mental constitution would make no difference in this respect.

A similar question has been much debated in a case in which there is greater reason for believing that we are conscious of Mind in action upon

Matter—I mean the case of the voluntary movements of our limbs. I determine to stretch out my arm, and the mental mandate is at once obeyed. But even here the nexus remains to us entirely mysterious. If I order a servant to bring in a scuttle of coals, and he does it, I am, in a sense, the cause of the occurrence. But that is only in a hyper-physical sense. There exists a sufficient physical cause in the contraction of my servant's muscles; which, again, involves the disappearance of an equivalent of heat in the combustion of his muscular tissues. The case is exactly the same in the instance of the movement of my own limbs at the bidding of my own will. Here also there is a physical antecedent—(a sufficient cause in the sense of the Physicists)—in the expenditure of my own bodily forces. The mental initiative is something outside (so to speak) of the physical series, and not connected with it in any way conceivable by the human intellect. I am here only asserting against Mr. Frankland the doctrine of his own teachers. “We are,” says J. S. Mill, “the causes of the motion of our own limbs in the same sense, and no other than that, in which cold causes ice, or a spark causes an explosion of gunpowder.” By this Mill meant, of course, that our volitions are mere antecedents, not producing causes of motion. ^* This is well-beaten ground; and whilst disclaiming the larger conclusions of the Positivist school, I have always thought it to be in the right upon this particular point. But if we are not justified in regarding a mental act as the vera causa of a voluntary motion, which we have exactly conceived and pre-adjusted, how much less is it allowable to posit a like act as the underlying cause of an unknown and unsuspected change in the cerebral matter.

The terms in which Mr. Frankland expresses his doctrine seem to warrant the interpretation I have been putting upon them, namely, that the “noumena” in the mental series are causes of the phenomena in the physical series; and my remarks have applied to the theory understood in this sense. But taking the paper as a whole, it is rather perhaps its true meaning that “noumena” and “phenomena” (if not identical) are common effects of a single cause, or motions of a single substance; the supposed cause, a substance, being within the circle of our own consciousness—being, in fact, in each man's case, his own mind—himself. To put it shortly: Thought and Cerebration are to be regarded equally as vibrations of our own selfconscious Substance; or even as one and the same vibration. From this is drawn the further inference, that our own self-conscious substance is a portion of the universal substance.

I have no right to press against Mr. Frankland the dicta of masters in the school to which he apparently belongs. As an independent thinker,

he has, of course, a right to discard any part of their doctrine which he conceives to he unsound. But the disciple often finds himself involved, by a partial departure from the established creed of his sect, in unexpected inconsistency. With this preface, I wish to cite a few lines from Professor Bain's “Compendium” (Appendix, p. 98). After asserting that, “Everything that we know, or can conceive, may be termed a quality or attribute,” he pertinently inquires, what is left to stand for ‘substance?’—and answers the query as follows:—“One way out of the difficulty is to postulate an unknown and unknowable entity, underlying, and in some mysterious way holding together, the various attributes. We are said to be driven by an intuitive and irresistible tendency to make this assumption; which intuition is held to justify us in such an extreme measure. There is an unknowable substance, “matter,” the subject of the attribute inertia, and of all the special modes of the different kinds of matter—gold, marble, water, oxygen, and the rest. The same hypothetical unknown entity is expressed in another antithesis—the noumenon as against the phenomenon; what is, in contrast to what appears.” Now, Mr. Frankland seems to think that in the particular class of experiences which he has selected he has evaded the difficulty insisted upon by Bain. Self-consciousness has given him entrance behind the scenes of external Nature which he can now contemplate ab intra. He needs not “to postulate an unknown and unknowable entity,” since he is himself the entity observed. In the co-related phenomena of intellect and brain he seems to recognize himself as selfconscious substance, simultaneously cognizant of his own being, of the material organism with which it is allied, and of the nexus between the two. This is his key to the enigma of the Kosmos. If I interpret him rightly, he has at all events emerged from Phenomenalism, and may be welcomed over by the Ontologists. Differing, ad I do myself, from Professor Bain, I cannot here press his authority upon Mr. Frankland. In regard to the idea of “substance,” Mr. Frankland is clearly at liberty to reject Bain's characteristic attempt to explain away a notion which human thought can not dispense with, and will ever insist upon supplying. Nor should I quarrel with the application, to mind, of the term “substance,” which is properly a metaphysical notion. The use of the term in theology is familiar. Spinoza regards God as a substance. But every argument which I have adduced to show that the cerebral changes are not effects of mental causes within our consciousness is also valid to prove that they are not accidents or motions of our own mental substance. This supposed substance is, be it remembered, ex hypothesi, a self-conscious entity, and could not be ignorant of its own vibration, or even of its own capability of vibration. Besides which, as I have already urged, the changes, or vibrations, are

demonstrably the physical consequents of physical antecedents. The chain of physical causation is complete in itself.

There is yet another defect, as it seems to me, which ought to be pointed out in Mr. Frankland's theory. It will not fit the case in which cerebral phenomena must be regarded as antecedents of mental; as in the instance of diseases and lesions of the brain, idiocy, and old age. If we suppose that, in the case of the voluntary exercise of intellectual power, mind may detect itself in action upon matter, it is equally true in the cases above suggested that the relation is reversed, and matter is found in action upon mind. The causal nexus must be affirmed in all cases, or rejected in all.

In any view of it, I prefer Mr. Frankland's theory to the naked materialism of Professor Huxley's essay on the “Physical Basis of Life.” It is better, I mean more philosophical, to regard the motions of a man's brain as physical effects of his mind or will, than to reverse the supposed order of causation, and affirm, with Huxley, that mind is “the expression of molecular changes” in the protoplasm of the cerebral cells. I reject both opinions; but, in so doing, must not be thought to deny the obvious truth that the human mind is made manifest in and by a material organism. It is only through such an organism that we can communicate with each other. We need not seek, in the obscure, involuntary, and to us inexpressive, motions of the brain, for proofs of exact correspondence between the mind and the physical organism. In the face, voice, and eye of man, we have the familiar exponents of his intellect and soul. Cerebral anatomy, with its dark lantern, will never add a perceptible ray to the broad daylight of conviction in which we live upon this subject. As regards our undoubted command over these well-known indicia of thought and feeling, it is psychical, not physical; as I have already tried to explain in the case of voluntary movement of the limbs. Behind (so to speak), and beyond, the innermost nerve-centres, sits the Will, apart from the material apparatus; and its mandates are transmitted, we know not how, we know not why, by ways inscrutable to science, never to be laid bare by scalpel or dissecting-needle, to the corporeal agents. It is in vain, as Professor Bain points out, that we “insist on some kind of local or space-relationship between the extended and unextended.” “A certain mystery,” he admits, “has attached to the union of mind and body.” The mystery, thus spoken of in the past tense, remains a mystery, and I believe will ever do so. Our minds are manifested in material phenomena, but are not themselves the causes of these phenomena; neither are they the effects; nor can any mental be identified with any physical event.

But, again, I must not be supposed to deny that mind, or, as I prefer to say, a mind, is the true ultimate cause alike of the human intellect and of