A manifests itself. The line of mental sequence is thus, not mind causing body, and body causing mind, but mind-body giving birth to mind-body; a much more intelligible position. For this double, or conjoint causation, we can produce evidence; for the singlehanded causation we have no evidence. If it were not my peculiar province to endeavor to clear up the specially metaphysical difficulties of the relationship of mind and body, I would pass over what is to me the most puzzling circumstance of the relationship, and indeed the only real difficulty in the question. I say the real difficulty, for factitious difficulties in abundance have been made out of the subject. It is made a mystery how mental functions and bodily functions should be allied together at all. That, however, is no business of ours; we accept this alliance as we do any other alliance, such as gravity with inert matter, or light with heat. As a fact of the universe, the union is, properly speaking, just as acceptable, and as intelligible, as the separation would be, if that were the fact. The real difficulty is quite another thing. outgoing responses in action, the mental lar mode of cerebral action henceforth succession is not for an instant dissevered from a physical succession. new prospect bursts upon the view; there is a mental result of sensations, emotion, thought, terminating in outward displays or speech or gesture. Parallel to this mental series is the physical series of facts, the successive agitation of the physical organs called the eye, the retina, the optic nerve, optic centres, cerebral hemispheres, outgoing nerves, muscles, etc. There is an unbroken physical circle of effects, maintained while we go the round of the mental circle of sensation, emotion, and thought. It would be incompatible with everything we know of the cerebral action, to suppose that the physical chain ends abruptly in a physical void, occupied by an immaterial substance; which immaterial substance, after working alone, imparts its results to the other edge of the physical break, and determines the active response-two shores of the material with an intervening ocean of the immaterial. There is, in fact, no rupture of nervous continuity. The only tenable supposition is, that mental and physical proceed together, as undivided twins. When, therefore, we speak of a mental cause, a mental agency, we have always a twosided cause; the effect produced is not the effect of mind alone, but of mind in company with body. That mind should have operated on the body, is as much as to say, that a two-sided phenomenon, one side being bodily, can influence the body: it is, after all, body acting upon body. When a shock of fear paralyses digestion, it is not the emotion of fear, in the abstract, or as a pure mental existence, that does the harm: it is the emotion in company with a peculiarly excited condition of the brain and nervous system and it is this condition of the brain that deranges the stomach. When physical nourishment, or a physical stimulant, acting through the blood, quiets the mental irritation, and restores a cheerful tone, it is not a bodily fact causing a mental fact by a direct line of causation; the nourishment and the stimulus determine the circulation of blood to the brain, give a new direction to the nerve currents, and the mental condition corresponding to this particu What I have in view is this: when I speak of mind as allied with bodywith a brain and its nerve currents-I can scarcely avoid localizing the mind, giving it a local habitation. I am thereupon asked to explain what always puzzled the schoolmen, namely, whether the mind is all in every part, or only all in the whole; whether in tapping any point I may come at consciousness, or whether the whole mechanism is wanted for the smallest portion of consciousness. One might perhaps turn the question by the analogy of the telegraph wire, or the electric circuit, and say that a complete circle of action is necessary to any mental manifestation; which is probably true. But this does not meet the case. The fact is that, all this time that we are speaking of nerves and wires, we are not speaking of mind, properly so called, at all; we are putting forward physical facts that go along with it, but these physical facts are not the mental fact, and they even preclude us from thinking of the mental fact. We are in this fix: mental states and ness. bodily states are utterly contrasted; they cannot be compared, they have nothing in common except the most general of all attributes, degree and order in time; when engaged with one we must be oblivious with all that distinguishes the other. When I am studying a brain and nerve communicating, I am engrossed with properties exclusively belonging to the object or material world; I am at that moment (except by very rapid transitions or alternations) unable to conceive a truly mental fact, my truly mental consciousOur mental experience, our feelings and thoughts, have no extension, no place, no form or outline, no mechanical division of parts; and we are incapable of attending to anything mental until we shut off the view of all that. Walking in the country in spring, our mind is occupied with the foliage, the bloom, and the grassy meads, all purely objective things; we are suddenly and strongly arrested by the odor of the May-blossom; we give way for a moment to the sensation of sweetness; for that moment the objective regards cease; we think of nothing extended; we are in a state where extension has no footing; there is, to us, place no longer. Such states are of short duration, mere fits, glimpses; they are constantly shifted and alternated with object states, but while they last and have their full power we are in a different world; the material world is blotted out, eclipsed, for the instant unthinkable. These subject-moments are studied to advantage in bursts of intense pleasure, or intense pain, in fits of engrossed reflection, especially reflection upon mental facts; but they are seldom sustained in purity beyond a very short interval; we are constantly returning to the object side of things-to the world where extension and place have their being. This, then, as it appears to me, is the only real difficulty of the physical and mental relationship. There is an alliance with matter, with the object, or extended world; but the thing allied, the mind proper, has itself no extension, and cannot be joined in local union. Now, we have no form of language, no familiar analogy, suited to this unique conjunction; in comparison with all ordinary unions, it is a paradox or a contradiction. We understand union in the sense of local connection; here is a union where local connection is irrelevant, unsuitable, contradictory, for we cannot think of mind without putting ourselves out of the world of place. When, as in pure feeling-pleasure or pain-we change to the subject attitude from the object attitude, we have undergone a change not to be expressed by place; the fact is not properly described by the transition from the external to the internal, for that is still a change in the region of the extended. The only adequate expression is a change of state: a change from the state of the extended cognition to a state of unextended cognition. By various theologians, heaven has been spoken of as not a place, but a state; and this is the only phrase that I can find suitable to describe the vast, though familiar and easy, transition from the material or extended, to the immaterial or unextended side of the universe of being. When, therefore, we talk of incorporating mind with brain, we must be held as speaking under an important reserve or qualification. Asserting the union in the strongest manner, we must yet deprive it of the almost invincible association of union in place. An extended organism is the condition of our passing into a state where there is no extension. A human being is an extended and material thing, attached to which is the power of becoming alive to feeling and thought, the extreme remove from all that is material; a condition of trance wherein, while it lasts, the material drops out of view-so much so, that we⚫ have not the power to represent the two extremes as lying side by side, as container and contained, or in any other mode of local conjunction. The condition of our existing thoroughly in the one, is the momentary eclipse or extinction of the other. The only mode of union that is not contradictory is the union of close succession in time; or of position in a continued thread of conscious life. We are entitled to say that the same being is, by alternate fits, object and subject, under extended and under unextended consciousness; and that without the extended consciousness the unextended would not arise. Without certain peculiar modes of the extended-what we call a cerebral organization, and so on-we could not have those times of trance, our pleasures, our pains, and our ideas, which at present we undergo fitfully and alternately with our extended consciousness. Having thus called attention to the metaphysical difficulty of assigning the relative position of mind and matter, I will now state briefly what I think the mode of dealing with mind in correlation with the other forces. That there is a definite equivalence between mental manifestations and physical forces, the same as between the physical forces them selves, is, I think, conformable to all the facts, although liable to peculiar difficulties in the way of decisive proof. I. The mental manifestations are in exact proportion to their physical supports. If the doctrine of the thorough-going connection of mind and body is good for anything, it must go this length. There must be a numerically-proportioned rise and fall of the two together. I believe that all the unequivocal facts bear out this proportion. Take first the more obvious illustrations. In the employment of external agents, as warmth and food, all will admit that the sensation rises exactly as the stimulant rises, until a certain point is reached, when the agency changes its character; too great heat destroying the tissues, and too much food impeding digestion. There is, although we may not have the power to fix it, a sensational equivalent of heat, of food, of exercise, of sound, of light; there is a definite change of feeling, an accession of pleasure or of pain, corresponding to a rise of temperature in the air of 10 deg., 20 deg., or 30 deg. And so with regard to every other agent operating upon the human sensibility: there is, in each set of circumstances, a sensational equiva lent of alcohol, of odors, of music, of spectacle. It is this definite relation between out ward agents and the human feelings that renders it possible to discuss human interests from the objective side, the only accessible side. We cannot read the feelings of our fellows; we merely presume that like agents will affect them all in nearly the same way. It is thus that we measure men's fortunes and fe licity by the numerical amount of certain agents, as money, and by the absence or low degree of certain other agents, the causes of pain and the depressors of vitality. And though the estimate is somewhat rough, this is not owing to the indefiniteness of the sensational equivalent, but to the complications of the human system, and chiefly to the narrowness of the line that everywhere divides the wholesome from the unwholesome degrees of all stimulants. Let us next represent the equivalence under vital or physiological action. The chief organ concerned is the brain; of which we know that it is a system of myriads of connecting threads, ramifying, uniting, and crossing at innumerable points; that these threads are actuated or made alive with a current influence called the nerve force; that this nerve force is a member of the group of correlated forces; that it is immediately derived from the changes in the blood, and in the last resort from oxidation, or combustion, of the materials of the food, of which combustion it is a definite equivalent. We know, farther, that there can be no feeling, no volition, no intellect, without a proper supply of blood, containing both oxygen and the material to be oxidized; that, as the blood is richer in quality in regard to these constituents, and more abundant in quantity, the mental processes are more intense, more vivid. We know also that there are means of increasing the circulation in one organ, and drawing it off from another, chiefly by calling the one into greater exercise, as when we exert the muscles or convey food to the stomach; and that, when mental processes are more than usually intensified, the blood is proportionally drawn to the brain; the oxidizing process is there in excess, with corresponding defect and detriment in other organs. In high mental excitement, digestion is stopped; muscular vigor is abated except in the one form of giving vent to the feelings, thoughts, and purposes; the general nutrition languishes; and, if the state were long-continued or oft-repeated, the physical powers, strictly so called, would rapidly deteriorate. We know, on the other extreme, that sleep is accompanied by reduced circulation in the brain; there is in fact a reduced circulation generally; while of that reduced amount more goes to the nutritive functions than to the cerebral. In listening to Dr. Frankland's lecture on Muscular Power, delivered last year at the Royal Institution of London, I noticed that, in accounting for the various items of expenditure of the food, he gave "mental work" as one heading, but declined to make an entry thercinunder. I can imagine two reasons for this reserve, the statement of which will further illustrate the general position. In the first place, it might be supposed that mind is a phenomenon so anomalous, uncertain, so remote from the chain of material cause and effect, that it is not even to be mentioned in that connection. To which I should say, that mind is indeed, as a phenomenon, widely different from the physical forces, but, nevertheless, rises and falls in strict numerical concomitance with these: so that it still enters, if not directly, at least indirectly, into the circle of the correlated forces. Or, secondly, the lecturer may have held that though a definite amount of the mental manifestations accompanies a definite amount of oxidation in the special organs of mind, there is no means of reducing this to a measure, even in an approximate way. To this I answer, that the thing is difficult, but not entirely impracticable. There is a possibility of giving, approximately at least, the amount of blood circulating in the brain, in the ordinary waking state; and, as during a period of intense excitement we know that there is a general reduction, almost to paralysis, of the collective vital functions, we could not be far mistaken in saying that in that case, perhaps one-half or one-third of all the oxidation of the body was expended in keeping up the cerebral fires. It is a very serious drawback in any department of knowledge, where there are relations of quantity, to be unable to reduce them to numerical precision. This is the case with mind in a great degree, although not with it alone; many physical qualities are in the same state of unprecise measurement. We cannot reduce to numbers the statement of a man's constitutional vigor, so as to say how much he has lost by fatigue, by disease, by age, or how much he has gained by a certain healthy regimen. Undoubt NEW SERIES-VOL. VL., No. 5. edly, however, it is in mind that the difficulties of attaining the numerical statement are greatest, if not nearly insuperable. When we say that one man is more courageous, more loving, more irascible than another, we apply a scale of degree existing in our own mind, but so vague that we may apply it differently at different times, while we can hardly communicate it to others exactly as it stands to ourselves. The consequence is, that a great margin of allowance must always be made in those statements; we can never run a close argument, or contend for a nice shade of distinction. Between the extremes of timidity and courage of character the best observer could not entertain above seven or eight varieties of gradation, while two different persons consulting together could hardly agree upon so minute a subdivision as that. The phrenologists, in their scale of qualities, had the advantage of an external indication of size, but they must have felt the uselessness of graduating this beyond the delicacy of discriminating the subjective side of character; and their extreme scale included twenty steps or interpolations. Making allowance for this inevitable defect, I will endeavor to present a scries of illustrations of the principle of correlation as applied to mind, in the manner explained. I deal not with mind directly, but with its material side; with whose activity, measured exactly as we measure the other physical forces, true mental activity has a definite correspondence. Let us suppose, then, a human being with average physical constitution, in respect of nutritive vigor, and fairly supplied with food and with air, or oxygen. The result of the oxidation of the food is a definite total of force, which may be variously distributed. The demand made by the brain, to sustain the purely mental functions, may be below average, or above average; there will be a corresponding but inverse variation of the remainder available for the more strictly physical processes, as muscular power, digestive power, animal heat, and so on. In the first case supposed, the case of a small demand for mental work and excitement, we look for, and we find, a better physique-greater muscular 37 power and endurance, more vigor of digestion, rendering a coarser food sufficient for nourishment, more resistance to excesses of cold and heat: in short, a constitution adapted to physical drudgery and physical hardship. Let Take now the other extreme. there be a great demand for mental work. The oxidation must now be disproportionately expended in the brain; less is given to the muscles, the stomach, the lungs, the skin, and secreting organs generally. There is a reduction of the possible muscular work, and of the ability to subsist on coarser food, and to endure hardship. Experience confirms this inference; the common observation of mankind has recognized the fact-although in a vague, unsteady form-that the head worker is not equally fitted to be a hand worker. The master, mistress, or overseer has each more delicacy of sense, more management, more resource, than the manual operatives, but to these belongs the superiority of muscular power and persistence. pronounce it to be a very considerable fraction of the entire work done in the system. interests during mental exertion is so The privation of the other apparent, so extensive, that if the exertion should happen to be long continued, order to stave off general insolvency. a liberal atonement has to be made in Mental excess counts as largely as muscular excess in the diversion of power: it would be competent to suppose either the one or the other reducing one-half of their proper amount. In the remaining forces of the system to be on the same simple plan of redressing both cases, the work of restoration must the inequality, of allowing more than the average flow of blood to the impoverished organs for a length of time corresponding to the period when their nourishment has been too small. It is in this consideration that we seem to have the reasonable, I may say the arithmetical, basis of the constitutional treatment of chronic disease. We repay the debt to nature by allowing the and less taxed, according to the degradaweakened organ to be better nourished tion it has undergone by the opposite line of treatment. In a large class of diseases we have obviously a species of to the sound method of readjusting the insolvency, to be dealt with according relations of expenditure and income. And, if such be the true theory, it seems to follow that medication is only an inferior adjunct. Drugs, even in their happiest application, can but guide and favor the restorative process; just as the stirring of a fire may make it burn, provided there be the needful fuel. There is nothing incompatible with the principle in allowing the possibility of combining, under certain favorable conditions, both physical and mental exertion in considerable amount. fact, the principle teaches us exactly In how the thing may be done. Improve the quality and increase the quantity of the food; increase the supply of oxygen by healthy residence; let the habitual muscular exertion be such as to strengthen and not impair the functions; abate as much as possible all excesses and irregularities, bodily and mental; add the enormous economy of an educated disposal of the forces; and you will numerically-statable relation, between There is thus a definite, although not develop a higher being, a greater aggre- the total of the physico-mental forces gate of power. You will then have and the total of the purely physical more to spare for all kinds of expen- processes. The grand aggregate of the diture-for the physico-mental, as well oxidation of the system includes both; as for the strictly physical. What other and, the more the force taken up by one, explanation is needed of the military the less is left to the other. Such is the superiority of the officer over common soldier? of the general efficien- the other forces of Nature. We do not the statement of the correlation of mind to cy of the man nourished, but not enervated, by worldly abundance ? deal with pure mind,-mind in the entity of that description. abstract; we have no experience of an with a compound or two-sided pheWe deal nomenon-mental on one side, physical spondence in degree, although a differon the other; there is a definite corre It may be possible, at some future stage of scientific inquiry, to compute the comparative amount of oxidation in the brain during severe mental labor. Even now, from obvious facts, we must |
