A Review of the Systems of Ethics Founded on the Theory of Evolution Part 23

[108] See especially Darwin: "The Variation of Animals and Plants under Domestication"; Haeckel: "Naturliche Schopfungsgeschichte," 8th ed., 1889, p. 179 _et seq._

[109] "Die Entstehung der Arten auf Grund von Vererben erworbener Eigenschaften," p. 204 _et seq._

[110] Ibid. p. 190 _et seq._

[111] "Entstehung der Arten," p. 15.

CHAPTER II

INTELLIGENCE AND "END"

It is interesting to notice the opinions of different scientists and philosophers as to the extent to which reason is diffused in the universe, where the point lies at which the boundary line is to be drawn between reason and an automatism of instinct or organic action, or whether any such point can be found at all, whether reason, at least as consciousness and will, is not inherent in all life, or at least in all animal life, or whether it is not, indeed, to be regarded as the cause of motion even outside life, in the inorganic as well as the organic.

There is no need to remind ourselves of the philosophic conception of the World as Will, the Philosophy of the Unconscious, or the Theory of Monads. The theories that specialists in physical science have arrived at, through the results of wide-reaching investigations in their own peculiar branch, are as various as those of philosophers. Darwin carefully avoids drawing any distinct limit-line between reason and instinct, but remarks that "A little dose of judgment or reason, as Pierre Huber expresses it, often comes into play, even with animals low in the scale of nature."[112] Haeckel says: "Unbia.s.sed comparison and unprejudiced test and observation place it beyond doubt that so-called 'instinct' is nothing else than a sum of soul-activities which, originally acquired by adaptation, have been fixed by habit and carried down from generation to generation by inheritance. Originally performed with consciousness and reflection, many instinctive actions of the animals have become, in the course of time, unconscious, exactly as is the case with the habitual activities of human reason. These, too, may, with like justice, be looked upon as the workings of innate instinct, as, indeed, the impulse to self-preservation, maternal love, and the social instinct often are regarded. Again, instinct is neither distinctively an attribute of the brain of the animal, nor is the reason an especial endowment of human beings. On the contrary, an impartial doctrine of soul recognizes a long, long, descending scale of gradual evolution in the life of the soul, which leads from higher to lower human beings, from more perfect to more imperfect animals, step by step, down to those forms whose simple nerve-ganglion furnishes the starting-point of all the cell-less brain-forms of this scale."[113] The lecture in which this pa.s.sage occurs not only argues further that the soul is composed of soul-activities as the brain is composed of cells, but finds in all living cells, "all protoplasm, the first element of all soul life, sensation in the simple forms of pain and pleasure, movement in the simple forms of attraction and repulsion. Only the degrees of development and combination of soul are different in different beings."

Du Prel, impressed with the evolution of order from disorder in the heavens as on the earth, ascribes this to universal sensation as a fundamental quality of all matter, which makes it continually tend towards a state of equilibrium in which collision is reduced to a minimum.[114] Some biologists ascribe sensation, or consciousness, to animal life alone; some ascribe consciousness to such animals only as possess a nervous system; some philosophers make a distinction between sensation, consciousness, and self-consciousness, as shown in the scale of animal life; some, again, approaching the problem from another side, lay emphasis on the difference between automatic and organic action, instinct, "blind impulse," and will. Carneri, as we have seen,[115]

holds that even the action of an animal so high in the scale as the b.u.t.terfly may be pure automatism, its fluttering when impaled merely the motion of a continued attempt at flight.

These differences in opinion seem to depend, in great measure, upon the end of the scale of being chosen as the starting-point in the development of theory. If we begin with man and a.s.sume intelligence to be the cause of design,--of the purposeful, the self-preserving,--in his action, we shall be likely to infer intelligence as the cause of self-preserving function in all animals, and we shall find great difficulty in drawing any distinct line between intelligence and automatism. If we are not students of inorganic nature, the evolution to be found also in it, up to the attainment of preservative forms of motion, may escape our observation, preoccupation with man and the self- or rather human-interested bias of observation blinding us to it; but if we carry our considerations, in an unprejudiced spirit, on beyond the province of life, we may, like Du Prel and others, arrive at a theory of intelligence as a universal property of matter. On the other hand, if we begin with inorganic matter and a.s.sume automatism to be the cause of its motion, we are likely, ascending the scale of organic existence, to interpret much of its function as due to material action and reaction, and may again, from this side, find so great difficulty in drawing the line where intelligence begins, that we may fall, as Carneri has done, into the opposite extreme to that last noticed, and interpret nearly all animal action as unintelligent or even insentient.

Let us look at the dilemma a little more closely. Might it not seem, from one point of view, as if the harmonious movements of the stars, by which they avoid their own destruction, must be referred to desire and will to avoid it? If all systems of material parts, without exception or distinction, tend, as Fechner, Du Prel, and Petzoldt a.s.sert, towards harmony of the parts such that the motion of these parts will become self-preservative, does it not seem logically necessary to a.s.sume that this self-preservation, arising in inorganic matter in the same manner as in organic matter, must be due to the same causes as those to which we ascribe action towards an end, action that involves self-preservation, in the broadest sense of the word, in man? May not the heavenly bodies, learning from experience in some way, as man does, gradually come to choose, though still in accordance with natural laws (as man also invariably chooses) that orbit which preserves them from collision? True, they must finally suffer destruction, but so, also, must the human individual, and the race of human beings. The difference of evolution and dissolution in the two cases is only one of time. Among different species of nervously organized beings, the duration of life also differs. Or, if we deny the existence of intelligence in inorganic nature, can we, at least, descending the scale of organic being, find any point of which we can say, "Here intelligence ends and automatism begins"? Shall we deny the existence of intelligence in plants, and if so, how shall we find that dividing line between the plant and animal kingdoms which the advancement of science in many directions is rendering, not more distinct, but less and less so? G. Th. Schneider says, in his book on "The Human Will": "The movements of touch and locomotion in the search for food are the first movements in which the specific animal-life may be recognized. In no plant is the groping caused by hunger to be observed."[116] But is this true? The insectivorous plants, for instance, open their leaves when their prey is digested, waiting for fresh prey; and they close them again when prey has again entered, thus practically grasping their victim and holding him fast. Although the nature of the plant prevents its moving from the spot where it grows, are these movements less a search for and capture of food than those of the animal? To say that the closing of the leaves depends upon the beginning of some chemical process in the plant furnishes us with no mark of distinction between the two, for it is equally true that chemical processes underlie animal motion; and to object that the reopening of the leaves is the result of the completion of a.s.similation gives us, also, no distinctive mark, since the animal's search for food is likewise the result of hunger and so connected with a particular state of the digestive organs. The action of insectivorous plants draws our attention because the process of a.s.similation involved so resembles animal digestion; but, as a point of fact, the opening of petals to receive the air and sun is as much a search for food as the opening of leaves to receive insect prey.

Schneider adds to the pa.s.sage above quoted, "A further difference between psychical and physiological movements is this, that the latter always remain the same, however the excitation changes, while the former have, now the character of attraction, now that of repulsion." It may be questioned whether this difference either can be demonstrated to be a distinctive mark. We have only to go into a dark cellar where the potatoes have begun to sprout, in order to see how plants that ordinarily grow upward will take every curve and angle in order to reach towards the light of some distant window. And if we turn one of the tubers about, we may watch the pallid sprout again turn to grow towards the far-away sunlight. Thomas A. Knight relates experiments in which plants of the Virginia creeper (_Ampelopsis quinquefolia_) were removed from one side of the house to the other, being, in each case, screened from perpendicular rays of the sun, and records that, in all cases, the tendrils turned in a few hours in a direction pointing to the centre of the house. One plant after being thus experimented with, was "removed to the centre of the house and fully exposed to the perpendicular light of the sun; and a piece of dark-colored paper was placed upon one side of it, just within reach of its tendrils; and to this substance they soon appeared to be strongly attracted. The paper was then placed upon the opposite side, under similar circ.u.mstances, and a piece of plate gla.s.s was subst.i.tuted; but to this substance the tendrils did not indicate any disposition to approach. The position of the gla.s.s was then changed, and care was taken to adjust its surface to the varying position of the sun, so that the light reflected might continue to strike the tendrils; which then receded from the gla.s.s, and appeared to be strongly repulsed by it."[117] Darwin writes of the insectivorous _Drosera rotundifolia_: "If young and active leaves are selected, inorganic particles not larger than the head of a small pin, placed on the central glands, sometimes cause the outer tentacles to bend inwards. But this follows much more surely and quickly, if the object contains nitrogenous matter which can be dissolved by the secretion. On one occasion, I observed the following unusual circ.u.mstance. Small bits of raw meat (which acts more energetically than any other substance), of paper, dried moss, and of the quill of a pen, were placed on several leaves, and they were all embraced equally well in about two hours. On other occasions the above-named substances, or more commonly particles of gla.s.s, coal-cinder (taken from the fire), stone, gold-leaf, dried gra.s.s, cork, blotting paper, cotton-wool, and hair rolled into little b.a.l.l.s, were used, and these substances, though they were sometimes well embraced, often caused no movement whatever in the outer tentacles, or an extremely slight and slow movement. Yet these same leaves were proved to be in an active condition, as they were excited to movement by substances yielding nitrogenous matter, such as bits of raw or roast meat, the yolk or white of boiled eggs, fragments of insects of all orders, spiders, etc. I will give only two instances.

"Minute flies were placed on the discs of several leaves, and on others b.a.l.l.s of paper, bits of moss and quill of about the same size as the flies, and the latter were well embraced in a few hours; whereas after twenty-five hours only a very few tentacles were inflected over the other objects. The bits of paper, moss, and quill were then removed from these leaves, and bits of raw meat placed on them; and now all the tentacles were soon energetically inflected.

"Again, particles of coal-cinder (weighing rather more than the flies used in the last experiment) were placed on the centres of three leaves: after an interval of nineteen hours, one of the particles was tolerably well embraced; a second by a very few tentacles; and a third by none. I then removed the particles from the two latter leaves, and put on them recently killed flies. These were fairly well embraced in seven and one-half hours, and thoroughly after twenty and one-half hours; the tentacles remaining inflected for many subsequent days. On the other hand, the one leaf which had in the course of nineteen hours embraced the bit of cinder moderately well, and to which no fly was given, after an additional thirty-three hours (_i.e._ in fifty-two hours from the time when the cinder was put on) was completely reexpanded and ready to act again."[118]

From these and many other experiments Darwin concludes that inorganic and some organic substances not attacked by the secretion of the leaf act much less quickly and efficiently than organic substances yielding soluble matter, which is absorbed.

He also writes of the curvature of radicles which come in contact with obstacles at right angles:--

"The first and most obvious explanation of the curvature is that it results merely from the mechanical resistance to the growth in its original direction. Nevertheless, this explanation did not seem to us satisfactory. The radicles did not present the appearance of having been subjected to a sufficient pressure to account for their curvature. Sachs has shown that the growing part is more rigid than the part immediately above, which has ceased to grow, so that the latter might have been expected to yield and become curved as soon as the apex encountered an unyielding object; whereas it was the stiff, growing part which became curved. Moreover, an object which yields with the greatest ease will deflect a radicle: thus, as we have seen, when the apex of the radicle of the bean encountered the polished surface of extremely thin tin-foil on soft sand, no impression was left on it, yet the radicle became deflected at right angles. A second explanation occurred to us, namely, that even the gentlest pressure might check the growth of the apex, and in this case growth could continue only on one side, and thus the radicle would a.s.sume a rectangular form; but this view leaves wholly unexplained the curvature of the upper part, extending for a length of 8-10 mm.

"We were therefore led to suspect that the apex was sensitive to contact, and that the effect was transmitted from it to the upper part of the radicle, which was excited to bend away from the touching object.

As a little loop of fine thread, hung on a tendril or on the petiole of a leaf-climbing plant, causes it to bend, we thought that any hard object affixed to the tip of a radicle, freely suspended and growing in damp air, might cause it to bend if it were sensitive, and yet would not offer any mechanical resistance to its growth.... Sachs discovered that the radicle a little above the apex is sensitive and bends like a tendril _towards_ the touching object. But when one side of the apex is pressed by any object, the growing part bends _away_ from the object."[119]

Acting on this idea, Darwin found, in many experiments, that the radicles of plants freely suspended in bottles, when brought into contact with the most yielding substances, bits of paper, etc., were deflected, in a very few hours, from their original course, and often at right angles to this. He says, further:--

"As the apex of a radicle in penetrating the ground must be pressed on all sides, we wished to learn whether it could distinguish between harder, or more resisting, and softer substances. A square of sanded paper almost as stiff as card, and a square of extremely thin paper (too thin for writing on) of exactly the same size (about one-twentieth of an inch), were fixed with sh.e.l.lac on opposite sides of the apices of twelve suspended radicles.... In eight out of the twelve cases, there could be no doubt that the radicle was deflected from the side to which the card-like paper was attached and towards the opposite side bearing the very thin paper.

"This occurred, in some instances, in nine hours, but in others not until twenty-four hours had elapsed. Moreover, some of the four failures can hardly be considered as really failures: thus, in one of them in which the radicle remained quite straight, the square of thin paper was found, when both were removed from the apex, to have been so thickly coated with sh.e.l.lac that it was almost as stiff as the card; in the second case, the radicle was bent upward into a semicircle, but the deflection was not directly from the side bearing the card, and this was explained by the two squares having become cemented laterally together, forming a sort of stiff gable from which the radicle was deflected; in the third case, the square of card had been fixed by mistake in front, and though there was deflection, this might have been due to Sachs's curvature; in the fourth case alone, no reason could be a.s.signed why the radicle had not been at all deflected."

Darwin found, moreover, by experiment, that, when the tip of a radicle is burnt or cut, "it transmits an influence to the upper adjoining part, causing it to bend away from the affected side." This deflection resembles, in a very striking manner, the avoidance of sources of injury and pain on the part of animals.

And at the end of his book on the Movements of Plants, which contains very many other experiments bearing on the question of sensitivity in plants, the author writes, "It is hardly an exaggeration to say that the tip of the radicle thus endowed, and having the power of directing the movements of the adjoining parts, acts like the brain of one of the lower animals."

It is true that the plant does not react with the rapidity which characterizes the animal; Darwin found that radicles are not sensitive to temporary contact, but only to long, though to slight pressure. It is also true that the physical basis of the movement is more simple, and so more easily traceable in the plant than in the animal organism; yet why lay such especial stress upon this side of plant-life, since it is acknowledged that the physical basis is by no means peculiar to it, but that, on the contrary, all life-processes, in the animal as well as in the plant, have their physical side, although greater complexity of organization may make this more difficult to follow in the one case than in the other?

But we may begin at the other end of the scale and examine the facts presented from the opposite point of view. The physicist demonstrates that force is indestructible; that is, that the sum of the motion and resistance to motion residing in indestructible matter is also imperishable, that all present motion must be regarded as the resultant of previous conditions of motion and resistance, as far back as we may go, until we reach some a.s.sumed primal state (which is only a.s.sumed and cannot be proved to have existed) in which the matter composing the universe is supposed to have been at complete rest; and that every resultant bears relations to its component factors of force that are constant, every component finding its full value in the resultant. What evidence has the present state of our solar system and the other systems of heavenly bodies revealed to us by the telescope to offer us in proof of their consciousness or sentience? How are the whirl and concentration of nebular mists, the crash and collision of elemental bodies, from which, by simple action and reaction, after ages of disharmony, only a comparative harmony is arrived at as inevitable result, evidence of aim, intention, will, consciousness, in the matter subject to this evolution?

Do we find anything here except blind law? The movements of plants, often directly favorable to self-preservation, may be explained by the arrangement of the cells and their chemical action. Or, if sentience must be a.s.sumed to be the cause of movement attaining ends of self-preservation in plants, how are we to account for organic and instinctive action in animals? How is it, for instance, that the new-born infant sucks, and the chicken but a few hours old, even though it has been hatched in an incubator apart from its kind, picks at the food strewn before it, aiming, too, with considerable precision?[120]

How does it happen that the process of breathing and digestion, the beating of the heart and the circulation of the blood, all so necessary to life, go on with regularity, though not directed by reason? Has the newly hatched chicken any experience to teach it what food is, and how it is to be seized; or does the caterpillar, which spins itself a coc.o.o.n, do this with the understanding that it is about to enter a new phase of existence? Or, if such important and, at first view, seemingly intelligent action can be explained as unreasoning instinct, why cannot many other actions of the lower animals be thus explained? Why may not nearly all, if not all of them, be thus explained, and consciousness be regarded as the exclusive property of man?

But how much of the action we term automatic, instinctive, or organic, reflex or "merely functional," can be positively a.s.serted to have no admixture of consciousness? If we examine our own action closely we shall often find that we were, in fact, conscious of much that seems, at first glance, purely automatic. It may appear to us, for instance, that reflection on the notes of a musical composition which we have known for a long time "by heart" hinders rather than helps us, even causing us sometimes to fail completely in our performance. But if we examine our condition at the time of such a failure, do we not usually find that, when we began to think about what we were playing, we were suddenly seized with a fear of failing and that the fear confused us? Or do we not find, at least, that withdrawal of our attention from the music by conversation that requires any concentration of thought is as likely to confuse us as too great attention to it? A friend of mine one day related to me the following experience: Having a felon upon his finger, he submitted to a surgical operation, for which the operator preferred to administer an anaesthetic. When he awoke to consciousness again, he was pleased to find the painful operation completely finished and the hand newly dressed. Asked whether he had experienced any pain, he answered, "Not a twinge," whereat the surgeon remarked that he had screamed and groaned during the operation. To this he replied that his action must have been merely reflex. An hour or so later, however, as he was at work, a sudden recollection of the whole operation came to him.

Persons undergoing dental operations under the influence of laughing-gas often scream and make convulsive movements as if in pain, though they declare, afterwards, in like manner, that they have felt nothing; but may not this be due, as in the case just cited, to a mere lapse of memory? Why, indeed, should the patient scream if not in pain? Again, there is a poison--curarine, the Indian arrow poison--which has power to deprive its victim of all motion, while leaving him, as has been ascertained in cases in which it has been used as a medicine, a consciousness that is more or less dimmed. May not the seeming dimness, however, be due to the incomplete function of memory when turned to events that transpired under its influence? And may not the action of so-called anaesthetics of all sorts involve simply a paralysis of action similar to that caused by the Indian arrow poison, together with a more complete lapse of memory than that ensuing upon the latter? To answer that anaesthetics affect the brain, and that therefore consciousness is not possible, is begging the question, for it is by just such experiments and experience of the apparent mental effects of anaesthetics in connection with peculiar brain conditions that theories of non-sensibility under these conditions have been arrived at. States of somnambulism generally used to be cla.s.sed as outside the sphere of memory and were therefore sometimes called unconscious; but recent experiments in hypnotism have shown that similar states to these may be remembered or not remembered according to the individual case, and that persons who, when awakened, ordinarily recall nothing of that which has pa.s.sed in the hypnotic state may be made to recall all the events of that state if commanded to do so before awakening. Pfluger has attempted to demonstrate, by many experiments, that consciousness is not confined to the brain but is also connected with the spinal cord;[121] why, however, draw a line at the spinal cord? Is not nerve substance the same with that from which the spinal cord and the brain develop, are not all nerve cells primarily mere modifications of cells of the outer skin?

Of unconsciousness in ourselves we can have no more an immediate and direct knowledge than of unconsciousness outside ourselves, since, in order to be immediately known, it would have to be present in consciousness; and a conscious unconsciousness is a self-contradiction.

We can only witness to a failure of memory at certain points (which failure has already been shown to be untrustworthy as evidence) or to movements of our body to which we can supply no corresponding conscious states as premeditation. But our inability to testify to such is merely negative. A great deal has been made, in one way and another, of the fact that there are links in premeditated action which do not come into consciousness, there being no knowledge, for instance, of the processes in nerve and muscle between the movement of the arm in writing and the premeditation of such movement. As a fact, however, none of the physiological processes which accompany the psychical are present to our consciousness except as given through the senses or through nerve-transmission similar to that of sense-perception. The conscious elements of any present state of thought do not include the changes in brain-matter concomitant with them. But the question may be raised, as Haeckel raises it,--though perhaps somewhat differently,--in his essay on Soul-cells and Cell-souls, as to whether the brain-cells themselves are not endowed with consciousness; and any answer in the negative is, evidently, an a.s.sumption, of which we can give no proof. Indeed, the question may be asked, and has been asked, whether the remarkable white blood corpuscles which traverse our body, and are so similar to certain lower forms of life, are not to be regarded as distinct beings, or whether, in fact, all the cells whose combined life and movement make up our own are not endowed with distinct being and consciousness. Again an answer in the negative is evidently a mere a.s.sumption. And why stop, in this case, exactly with the cells of animal life; why not apply our question to those of plant life also? Why not, indeed, suppose all forms to be endowed with consciousness, all harmonious motion to be accompanied by pleasure, all dissolution and conflict by pain? From a.n.a.logy we may conclude something, but from mere non-a.n.a.logy nothing.

Our experience may ent.i.tle us to the a.s.sertion that all beings possessing a nervous system are endowed with consciousness, but we cannot conclude, therefore, that all beings not possessing a nervous system are not endowed with consciousness. We have a.s.sociated consciousness with acts peculiar to man, and hence inferred its presence in similar movements of animals similarly constructed. But if we could examine the physiological accompaniments of our own thought and feeling and their issue in action, if we could look on at all the details, the chemical and mechanical changes of the physiological processes, what hint should we find in these more than in any other physical processes, from which to infer consciousness? They are not the less rigidly in accordance with natural law than any other. But our observation of all other processes than those of our own organism is a mere extraneous one, like this we have imagined of the processes of our own body; if there were consciousness in other forms we could not enter into it; and how can we prove extraneously its non-existence? Our own "stability" of function and the stability of all life-motion has been developed in a perfectly similar manner to that by which the stability of the heavenly bodies has been developed, the physical side of the process being just as fully a matter of action and reaction, and our action towards ends the slowly progressive result of this course of action and reaction, just as is the case with the harmonious movements of the systems of the heavens. It would, moreover, be perfectly easy to formulate a purely physical and mechanical explanation of our action, as Carneri does of the action of ants and other species,--to explain the plucking of a rose, for instance, as mere reaction upon the sense of smell and sight, or as the mere mechanical action of cell-matter.

But, again, on the other hand: If it is true that the nervous system is developed from cells of the outer covering of the body, it is, nevertheless, not true that those primary cells are the nervous system, any more than it is true that the lowest forms of life, from which man has developed, are human beings. Rudimentary eyes exist in some animals in the form of mere pigment spots, but we do not suppose these pigment spots to endow the animal with sight as we understand it. Sight is not a function of all forms of life, neither is hearing, and these powers have developed out of forms of animal life in which they did not exist; why then is it necessary to suppose consciousness to be a property of all forms of life because we know it to appear in some higher developments of life? Why may it not arise, as do sight and hearing, by gradual evolution, as a function of special organisms? Have we any direct knowledge of consciousness except in connection with certain normal conditions of our own brain? And, this being said, have we any means left by which we can prove the existence of consciousness, except in connection with a brain similar to our own?

What grounds have we for a.s.suming the existence of consciousness where the a.n.a.logy of our own organization does not furnish us with an argument? If we argue from the a.n.a.logy of our own experience to the existence of consciousness in animals whose organization is similar to our own, and then, following down the scale of life, find no pause or gap at which to draw an exact line, we must not the less forget that with the diminis.h.i.+ng a.n.a.logy the force of our inference diminishes in like degree. Or where is the logical necessity of inferring that consciousness must exist in the inorganic either because the organic originally developed from the inorganic, or because it suffers continually a renewal by nourishment, which is, in effect, as much a development from the inorganic as the supposed primal one? The pigment spot from which the eye arises is not the eye, simple protoplasm is not the organized human being; whence does the physical organization arise?

Are we to suppose it, too, as preexistent, "in a weaker form," or in any form, in the inorganic? Whence have we any grounds for a.s.suming that that which we know only in connection with a certain peculiar organization exists elsewhere? Are we to suppose the color blue to be present in certain chemical elements because their chemical compound is blue? Or how is it that even isomeric compounds may exhibit different qualities? Shall we regard the color as not essentially connected with the chemical const.i.tution of the supposed compound? As a matter of fact, color is one of the chemist's means of recognition. Or shall we "explain" the color by the length of light-waves or the construction of the eye, correcting, thus, one part of our experience by another, and a.s.suming one as fundamental and essential, the other as non-essential?

We "explain" sound as wave-movement in some outer medium and in the ear, correcting, thus, the hearing by sight or touch; does this mean that that part of our experience given us through the eye or hand alone is truth, and to be relied on and recognized as such, while the experience given us through the other senses is non-essential and not to be accepted or relied on? But if the eye gives us the truth, then why do we, in the case of color, correct it again by another phase of our experience? How are we to decide which is essential, the wave-movement that is (or may be made) perceptible to our eye, or the sound heard by our ear, the color directly seen or the length of the light-wave concluded from experiment? As a matter of fact, we emphasize one or the other according to the end we have in view in our experiment. Is it the length of the wave which causes the color, or the color which causes the particular wave-length? If we a.n.a.lyze brain-action as chemical action, do we prove thereby that the consciousness concomitant with this peculiar chemical action under these peculiar conditions must exist elsewhere under other conditions? Are the characteristics of one chemical compound the same as those of another because both compounds are matter and motion? If we prove that the brain contains cells similar to cells in other parts of the nervous system, that the whole nervous system arises, in the first instance, from epithelium cells, that the whole animal is descended from some primal protoplasmic cell, and that the cells of plants are similar, in many ways, to those of animals, do we thereby prove that consciousness exists except as coordinate with the peculiar cells and arrangements of cells in the brain? We have no precedent from which to argue, since consciousness is to us a unique feature of the universe; we know it immediately only as existent in ourselves, and in order to obtain any precedent must be guilty of a.s.suming it in order to prove it.

The dilemma seems, thus, as we a.n.a.lyse and inquire into it more closely, to increase rather than decrease in significance. How is any solution to be arrived at?

If we return to the beginning of our considerations on this point, we shall find that, in coming at the question from either side, we have made an a.s.sumption. Our first premises were as follows: a.s.suming that consciousness is the cause of movement by which man attempts to arrive at his ends, what reason have we for supposing consciousness to exist outside man? and, on the other hand: a.s.suming mechanical action and reaction to be the cause of movement in inorganic nature, what reason have we for a.s.suming this to be the cause of action in organic existence? Let us examine these a.s.sumptions more closely.

We may return to the theory of the gradual development of stable out of unstable conditions as stated in different ways by Zollner, Fechner, and Du Prel. As has been shown, the principle applies to organic as well as to inorganic nature, and is only a broader principle including that of the Survival of the Fittest. There is a physical side to all psychical functions, and everywhere our investigation shows us the physical following unchanging laws. The development of the Stable from the Unstable explains to us the evolution of function in the direction of the preservation of the organic forms of which it is the function, as well as the evolution of harmonious movement in the heavenly bodies. The explanation of the natural and necessary elimination of the inharmonious covers the whole ground, and seems to a.s.sign a cause for every form of preservative action, for the harmonious conduct which preserves the state or the family as a collection of individuals, as well as for the harmony of function that preserves the individual. As long as reason can change no smallest detail in the workings of the laws of nature, as long as it can never render any motion other than the exact resultant of the forces represented in it, what room remains for reason as a cause? Ought we not rather, though from a much broader and therefore more convincing, in fact from the broadest and hence most convincing view of the matter, to regard consciousness, as do many physiologists on narrower grounds, as the mere accompaniment of material processes?

But this brings us again to a consideration of the concept of cause.

What do we mean by cause? Above, we spoke of the "cause of motion"; do we designate by this term those factors of preceding motion which, continued, produce it as composite resultant? If so, why not subst.i.tute for the term "cause of motion," "component factors of motion"? But is this, in fact, all we meant by cause? Was there not, in our mind, as we made use of the term, a vague half-conception of some additional force beyond those so exactly summed up in the resultant, which, in some indefinable manner, guided the process? As has been sufficiently demonstrated, no such additional force can be shown to exist, or be logically a.s.sumed in theory, except in some transcendental sense; nature gives us only perfect equivalence of forces. A cause of motion except as the mere sum of its preceding components is, therefore, a natural impossibility. Hence the reason or consciousness cannot be a.s.sumed to be such a cause. But if consciousness cannot be regarded as such a cause additional to the component factors of motion, neither can anything outside consciousness be regarded as such a cause. Natural laws are often treated as if they const.i.tuted a cause; but they are not ent.i.ties which control nature: they are merely forms by which we express nature's constancy, uniformity. Neither is constancy or uniformity a controlling ent.i.ty: it is simply a generalization, if a universal one, whether we regard it as _a priori_ or as _a posteriori_. It appears, then, that we have no greater reason for regarding the constancy of nature or natural law as cause than we have for a.s.serting reason to be such.

In this connection the question may be in order, as to why the student of the natural sciences, who is in the habit of proclaiming, so loudly, the necessity or at least the constancy of everything in nature, should yet elect to a.s.sign to consciousness the character of the non-essential, that is the accidental. Action and reaction are, according to him, essential inherent properties of brain matter as such, but consciousness is merely a dependent. But who shall decide what part or form of force, what factors of the universe are accidental and what essential? If our a.s.sertion of constancy in natural phenomena means anything at all, it means that nothing is accidental, but that all factors of phenomena are essential. Is the bell the less silver to my eye because it appeals to my ear with sound, or the ball the less round to touch because my field of vision is flat? Even if we suppose forms of matter, and organic forms, to exist without consciousness, can we therefore a.s.sert consciousness to be any the less essential, any the less inherent in the nature of things, any the less existent and actual, where it appears? If so, what physiological function can we call inherent and essential, since these all also arise with evolution? Heat may exist without light, but is light therefore less essential than heat, where it arises? The very constancy which psychical phenomena exhibit would show their essential character as factors of the universe. Perhaps it is the attempt of the spiritualist to a.s.sign to consciousness something more than such a character which has led his adversary into the opposite error of a.s.serting it to be something less; but the two extremes of doctrine are quite equally far from that scientific method which holds to given phenomena. Materialism is as much metaphysics as Spiritualism is; and the materialist who condemns metaphysics condemns himself.

Consciousness belongs to the Actual; and the Materialism which a.s.signs it a place subordinate to that of other actual phenomena is as much dogmatism as is any theory which subordinates the other phases of the Actual to it. The fact that consciousness bears constant relation to certain physiological phenomena is no ground for p.r.o.nouncing it the effect and the physiological phenomena the cause, it the dependent and the physiological phenomena the independent factors; the relations of all forms of force to each other are constant. Heat is constant in its accompaniment of light; and yet who shall say the one is dependent, the other independent, the one cause, the other merely effect?

We have only to regard the theories of specialists in order to discover how easily habitual occupation with one particular side, form, factor, or phase of phenomena inclines one to regard that side as the only essential one, and all others as non-essential, dependent upon it, mere effect of which it is the cause. The physicist tends to interpret everything by mechanical action and reaction; the chemist lays more particular stress on the chemical properties of organic as of inorganic matter; the physiologist emphasizes cellular structure and combination, and makes much of brain cells, the spinal cord, the _nervus sympathicus_, and the special sense-organs; the biologist often regards the attraction and repulsion involved in the so-called sensibility of all forms of living matter as the cause of all life phenomena; the anatomist calls attention to the arrangement of organs with respect to each other, the mechanical adjustment of parts for function, the size and shape of bones as caused by weight and the angle of its incidence, etc., etc.; while the psychologist on the other hand refers everything to mental causality. For complete science, however, we need the aid of every special science,--of Physics, Chemistry, Biology, Physiology, Anatomy, Psychology, and all the other branches which can contribute to any side of our knowledge of nature. The desire within us for unity is strong, the impulse to simplify by referring everything to a single principle almost irresistible; and in so far as we do this through a conviction of the oneness of the universe as consisting of interdependent parts we are in a certain sense justified; but until we can grasp this unity in its totality, our one-sided reductions must remain false in so far as they make claim to include the whole of truth.

It may be most useful to choose out that side or phase of phenomena for any particular investigation which is most accessible to such investigation; where the links of the psychical fail, it may be necessary to scientific completeness or clearness to complete the chain with the aid of the physical, but it should be borne in mind that this is a device of reason for convenience' sake. It may be possible to imagine two worlds, one in which the physical evolution alone takes place and all phenomena peculiar to organic function arise through the action and reaction of organic matter;[122] but the question is not what we can imagine but what is: we can imagine many things which do not exist and are impossible to nature. The human reason has also found it possible to conceive of spirit unconnected with body.

The materialist calls triumphant attention to the constancy of material phenomena, and proves, by careful comparison with coordinate psychical phenomena, the uniformities in the latter. Disease of every kind, but particularly those forms of disease which attack especially the nervous system--brain and spinal cord and the nerve endings--furnish the strong points of his argument, which is thus based on facts no lover of truth desires to gainsay; but when the materialist has shown us all these facts, has he not proved, with regard to the psychical, exactly that constancy which ent.i.tles it to consideration as a part of the actual universe subject to natural law?

The materialist objects that if the physical side of nature is the essential one, the psychical cannot be essential. On what grounds is this claim based? Is the color of an object not essential to it because its shape is essential, or do the actual existence and change of color according to natural law interfere with the actual existence and change of shape according also to natural law? Does only one of our senses give us truth?

Logic is very ready with its definitions of "things" and their "properties" and "accidents," as Physics is very ready with its a.n.a.lyses of light and color and sound, and Physiology with its a.n.a.lyses of the sense organs and their relations to color and sound. But shall we accept only the physiological a.n.a.lysis of cell form and action, and reject the sense-synthesis of sight or hearing as less important, less actual? Or are we to believe that the sense-function alone is essential and not also some actuality in its object, as of this or that color? Are we to believe that any property or accident of a thing may change, and the thing remain yet actually the same thing? What are our essences as separated from their properties and accidents? As a matter of fact, we know nothing except we know it as some particular thing, every change in which leaves it something different from what it was before. Changes of particular form or color are changes to some other particular form or color, unless they are such changes as withdraw the object from the reach of the special sense of sight before appealed to, as for instance in the case of evaporation. That one form of force may accompany or pa.s.s into another makes neither one of the concomitants and neither the preceding nor the succeeding form less real. As a fact, however, much superst.i.tion still remains with us as unconscious result of just such withdrawals from the perception of one sense and a.n.a.logous new appeals to some hitherto unaffected sense, although we are accustomed to flatter ourselves that science has long overcome this superst.i.tion. There is no change that is not a particular change, that is not according to constant laws of nature, and, as such, essential to nature. There is no phase of nature that exact science can consistently regard as non-essential. So that, even if reason does not exist in combination with all matter, we have no ground for regarding it as non-essential where it does exist, and no more reason for defining it as effect than we have for defining it as cause. Result it may be, as physiological function is result,--that is, an end-form of processes of change which we call evolution.

But we have found our disproof and also our proof of the existence of reason outside the human species fail us wherever the direct evidence of extreme a.n.a.logy is wanting, as soon as we cease to regard reason as a cause of physiological change. Perhaps it will be well for us to define more closely the province of reason, before we proceed further in our considerations. An exhaustive a.n.a.lysis is not necessary to our purpose and it would be useless to attempt it at this point of our argument. The relation of reason to action is what chiefly concerns us here, and in this connection Mr. Leslie Stephen's definition of it as that faculty which enables us to act with regard to the distant and future might seem to designate its important function.[123] Simple reaction on the present action of force belongs to all matter. However, when we consider further, a certain doubt may rise as to the exact correctness of this definition or description, for does not that which we call instinct often perform the same office for the animal as that which we have designated as the office of reason? Let us look into this question a little more closely. We may take, for instance, the case of those insects and other animals which, though never caring for or indeed seeing their offspring after the hatching of the latter, make provision at the laying of the eggs for their nourishment during the helplessness of the first period of their life; are we to suppose that these animals have any means of knowing that they are providing for their offspring?

Can they have learned the fact from their own parent whom they never saw, or from others of their own species who are in the same predicament as themselves? As Schneider points out,[124] the human infant must have sucked before it could have had any ideas, as individual, of the act of sucking. The newly hatched chickens of Eimer's experiments above referred to could scarcely have had any conception of the act of eating before they picked at their food. How happens it that the young of many of the lower animals which give no care to eggs or offspring yet know how to care for themselves after the peculiar manner of their kind? Once it is admitted that any acts which attain results that const.i.tute desirable ends for the acting subject need not be regarded as caused by knowledge of the ends, there is no reason to suppose that the principle may not hold of many acts in which a distinct knowledge of the end seems to play a part. But what do we mean by end?

Let us take, for instance, the act of eating. The biologist and the physiologist tell us that the end which eating serves is the preservation of life; and the biologist may further add--not the life of the individual, alone, but that of the species. The very consistent physiologist may princ.i.p.ally have in view, in eating, the preservation of his own health, and may even take into consideration, in a degree, his possible future offspring, guarding his own health with a view to theirs. With a minority of other men these more general and distant results may to some extent be kept in view as ends. But it is evident that, with the majority of people, they are, where ends at all, subordinate ones, the immediate satisfaction of hunger, the pleasure of eating, or the relief of physical depression, appearing oftener as chief end. And what is to be said of the new-born infant, which sucks when the breast is placed between its lips? what is the end which it has in view in taking nourishment? Shall we suppose it, as individual, to have any definite conception of the contrast between states of hunger and states of satisfaction, and to possess the knowledge that the act of sucking is the proper means to the attainment of satisfaction as an end? As the infant becomes the boy seating himself at table with a distinct conception of pleasure to be attained by the gratification of a vigorous appet.i.te, so the boy may become the physiologist eating with a view chiefly to his own health and to the further end of health in his offspring. How does it happen that, thus, the same act, the significance of which remains the same, may be performed and by the same individual yet with quite different ends, or perhaps in some cases (that of the infant) no end at all, in view?

When we perceive the sphex providing its eggs, as is its wont, with living and yet motionless and helpless insects, we can scarcely refrain from believing that it is inspired by parental affection thus to provide for its future young; and yet we might, with quite equal reason, suppose that the act of copulation, in the case of the sphex, must have in view the propagation of offspring and the preservation of the species, since this is its result also; we refrain from so supposing, simply because a common experience furnishes us with the knowledge that the act of copulation, most necessary to the propagation of offspring and the preservation of the species, may yet be performed with no direct view to either of these ends, the birth of offspring being even regarded, in many cases, as something to be avoided if possible. With respect to all manner of acts, we continually fall into error by imputing what would be our own end, in case we performed the act, to another individual of our own species performing it; and the danger of error is doubtless increased when we attempt to judge the ends of an entirely different species by ends in a degree common to our own species. There is no reason why we should not suppose that some less ultimate end than that of the preservation of offspring may be present to the consciousness of the sphex placing food about its eggs, just as some nearer end than preservation of the species, health of offspring, or even individual health may be present to the human individual in the acts of copulation or of food-taking. And there remains still the further question as to whether the care of the sphex for its eggs may not be, and continue forever, on the plane of the first act of food-taking in the human infant; and then the question again arises as to what the nature of that plane of action may be.

These questions must remain, I believe, in great part unanswered, considerations such as those noticed above making the inference even of like ends from like acts very untrustworthy, the inference of similar ends from similar acts still more so, and the inference of the existence of no end or consciousness at all a logical impossibility. However, a certain general clew is given us in the constant coordination of our own nervous system with psychical processes, from which we may infer psychical processes in some manner and degree similar to our own in species whose nervous system greatly resembles our own; the similarity need not be that of ends, however. The decreasing similarity of nervous organization as we descend the animal scale may be supposed to be coordinate with some decrease of psychical similarity. _Wherein_ this increasing dissimilarity consists, however, we have yet to inquire.