The Constructive Work of Driesch.
What in Reinke"s case came about almost unperceived, Driesch did with full consciousness and intention, following the necessity laid upon him by his own gradual personal development and by his consistent, tenacious prosecution of the problem. The acuteness of his thinking, the concentration of his endeavours through long years, his comprehensive knowledge and mastery of the material, the deep logicalness and consistent evolution of his "standpoints," and his philosophical and theoretical grasp of the subject make him probably the most instructive type, indeed, we may almost say, the very incarnation of the whole disputed question. In 1891 he published his "Mathematisch-mechanische Betrachtung morphologischer Probleme der Biologie," the work in which he first touched the depths of the problem. It is directed chiefly against the merely "historical" methods in biology, used by the current schools in the form of Darwinism. Darwinism and the Theory of Descent have been so far nothing more than "galleries of ancestors," and the science ranged under their banner is only descriptive, not explanatory. Instead of setting up contingent theories we must form a "conception" of the internal necessity, inherent in the substratum itself, in accordance with which the forms of life have found expression-a necessity corresponding to that which conditions the form-development of the crystal.
Experimental investigations and discoveries, and further reflection, resulted, in 1892, in his "Entwicklungsmechanische Studien," and led him to insist on the need for what the t.i.tle of his next year"s work calls "Biologie als selbstandige Grundwissenschaft." In this work two important points are emphasised. The first is, that biology must certainly strive after precision, but that this precision consists not in subordination to, but in co-ordination with physics. Biology must rank side by side with physics as an "independent fundamental science," and that in the form of tectonic. And the second point is, that the teleological point of view must take its place beside the causal. Only by recognising both can biology become a complete science.
In the "a.n.a.lytische Theorie der organischen Entwicklung" (1894) Driesch picks up the thread where he dropped it in the book before, and spins it farther, "traversing" his previous theoretical and experimental results.
In this work the author still strives to remain within the frame of the tectonic and machine-theory, but the edges are already showing signs of giving way. Life, he says, is a mechanism based upon a given structure (it is however a machine which is constantly modifying and developing itself).
Ontogenesis(98) is a strictly causal nexus, but following "a natural law the workings of which are entirely enigmatical" (with Wigand). Causality fulfils itself through "liberations," that is to say, cause and effect are not quant.i.tatively equivalent; and all effect is, notwithstanding its causal conditioning, something absolutely new and not to be calculated from the cause, so that there can be no question of mechanism in the strict sense. And the whole is directed by purpose.(99) The vital processes compel us to admit that it seems "as if intelligence determined quality and order." Driesch still tries to reconcile causes and purposes as different "modes of regarding things," but this device he afterwards abandons. We cannot penetrate to the nature of things either by the causal or by the teleological method. But they are-as Kant maintained-two modes of looking at things, both of which are postulates of our capacity for knowing. Each must stand by itself, and neither can have its sequence disturbed by the interpolation of pieces from the other. In the domain of the causal there can be no teleological explanation, and conversely; one might as well seek for an optical explanation of the synthesis of water; but both are true in their own place. The Madonna della Sedia, looked at microscopically, is a ma.s.s of blots, looked at macroscopically it is a picture. And it "is" both of these.
Driesch"s conclusions continue to advance, led steadily onwards by his experimental studies. In the "Maschinentheorie des Lebens,"(100) he attacks his own earlier theories with praiseworthy determination, and remorselessly pursues them to the monstrous conclusions to which they lead, and shows that they necessarily perish because of these. He had previously declared, at first emphatically, later with hesitation (we have already seen why), that every single vital process is of a physico-chemical kind, on the basis of a given "structure" of living beings. But now he considers the living organism as itself a result of vital processes-that is, of development. If this also is to be explained mechanically (as physico-chemical processes based on material structure), then the ovum must possess _in parvo_ this infinitely fine structure, by virtue of which it fulfils its own physiological processes of maintenance, and also becomes the efficient cause of the subsequent development. It must bear the type of the individual and of the species, as a rudiment (or primordium) within its own structure. Every specific type must, however, according to the theory of descent, be derived through an endless process of evolution, by gradual stages, from some primitive organism. Just as in the mechanical becoming of the individual organism, so the primitive protovum must also be extraordinarily intricate and complex in its organisation if it is to give rise to all the processes of evolution and development involved in the succeeding ontogenies, phylogenies, regenerations, and so forth. This is a necessary conclusion if the machine-theory be correct, and if we refuse to admit that vital phenomena are governed by specific laws. This consequence is monstrous, and the theory of the tectonists therefore false. But if it be false, what then?
Driesch answers this question in the books published in subsequent years.(101) In these he attains his final standpoint, and makes it more and more secure. The "machine-theory," and all others like it, are now definitely abandoned. They represent the uncritical dogmatism of a materialistic mode of thought, which binds all phenomena to substance, and refuses to admit any immaterial or dynamic phenomena. The alleged initial structure is nowhere to be found. The pursuit of things into the most minute details leads to no indication of it. The chromatin, in which the most important vital processes have their basis, is very far from having this machine-like structure; it is h.o.m.ogeneous. The formation of the skeleton, for instance, of a Plubeus larva is due to migratory spontaneously moving cells (comparable to the leucocytes of our own body, whose migrations and activities remind one much more of a social organism than of a machine). The organism arises, not from mechanical, but from "harmoniously-equipotential systems": that is to say, from systems every element of which has equal functional efficiency; so that each individual part bears within itself in an equal degree the potentiality of the whole-an impossibility from the mechanical point of view.
Driesch had given an experimental basis for this theory at an earlier stage, in his experiments on the initial stages of the development of sea-urchins, starfishes, zoophytes, and the like. A Planarian worm cut into pieces developed a new worm of smaller size from each part. A mutilated Pluteus larva developed a new food-ca.n.a.l, and restored the whole typical form. His experiment of 1892 went farther still, for he succeeded in separating the first four segmentation-cells of the sea-urchin"s egg; and from each cell obtained a developing embryo. These facts, he maintains, compel us to a.s.sume a mode of occurrence which is dynamically _sui generis_, a "prospective tendency" which is a sub-concept in the Aristotelian "Dynamis." And the essential difference between this kind of operation and a mechanical operation is, that the same typical effect is always reached, even if the whole normal causal nexus be disturbed. Even when forced into circuitous paths the embryo advances towards the same goal. Thus "vitalism," that is, the independence and autonomy of the vital processes, is proved. The effect required is attained through "action at a distance," a mode of happening which is specifically different from anything to be found in the inorganic world, and which has its _directive_, for instance, in the regeneration of lost parts, _not_ in anything corporeal or substantial, but in the end to be attained.
In his work on "Organic Regulations," Driesch collects from the most diverse biological fields more and more astonishing proofs of the activity of the living as contrasted with physico-chemical phenomena, and of the marvellous power the organism has to "help itself" and to attain the typical form and reach the end aimed at, even under the greatest diversity in the chain of conditions. The material here brought forward is enormous, and the author"s grasp of it very remarkable; and not the least of the merits of the book is, that the bewildering wealth and diversity of these phenomena, which are usually presented to us as isolated and uncoordinated instances, is here definitely systematised according to their characteristic peculiarities, and from the point of view of the increasing distinctness of the "autonomy" of the processes. The system begins with the active regulatory functions of living matter in the chemistry of metabolism (see particularly the phenomena of immunisation), and ascends through different stages up to the regulations of regeneration. There could be no more impressive way of showing how little life and its "regulations" can be compared to the "self-regulations" of machines, or to the restoring of typical states of equilibrium and of form in the physical and chemical domain, to which the mechanists are fond of referring.
The facts thus empirically brought together are then linked together in a theory, and considered epistemologically. We may leave out of account all that is included in the treatment of modern idealism, immanence-philosophy, and solipsism. All this does not arise directly out of the vitalistic ideas, though the latter are fitted into an idealistic framework. Extremely vivid is the excursus on respiration and a.s.similation. (All processes of building up and breaking down take place within the organism under conditions notoriously different from those obtaining in the laboratory. It is radically impossible to speak of a living "substance" according to the formula CxHyOz, which a.s.similates and disa.s.similates itself [sibi].) Excellent, too, are Driesch"s remarks on materialistic elucidations of inheritance and morphogenesis. It is quite impossible to succeed with epigenetic speculations on a material basis (_cf._ Haacke). Weismann is so far right, he admits, from his materialistic premisses when he starts with preformations. But his theory, and all others of the kind, can do nothing more than make an infinitely small photograph of the difficulty. They "explain" the processes of form-development and the regeneration of animals and plants, by constructing infinitely small animals and plants, which develop their form and regenerate lost parts. And Driesch holds it to be impossible to distribute a complicated tectonic among the elements of an equipotential system. In denying the materialistic theory of development, Driesch again determinedly "traverses" his own earlier views. He does this, too, when he now rejects the reconciliation between causality and teleology as different modes of looking at things. The teleological now seems to him itself a factor playing a part in the chain of causes, and thus making it teleological. The key-word of all is to him the "entelechy" of Aristotle.
In his last work on "The Soul," Driesch follows the impossibilities of the mechanical theories from the domain of vital processes into that of behaviour and voluntary actions.
The Views of Albrecht and Schneider.
An outlook and interpretation which Driesch(102) maintained for a while, but afterwards abandoned, has been developed in an original and peculiar fashion by Eugen Albrecht, Prosector and Pathologist in Munich.(103) It is the theory of different ways of looking at things. Albrecht indeed firmly adheres to the chemical and physical interpretation of vital processes, regards approximate completeness along these lines as the ideal of science, and maintains their essential sufficiency. But he holds that the mechanists have been mistaken and one-sided in that they have upheld this interpretation and mode of considering things as the sole and the "true"
one. According to our subjective att.i.tude to things and their changes, they appear to us in quite different series of a.s.sociations, each of which forms a complete series in itself, running parallel to the others, but not intruding to fill up gaps in them. Microscopic and macroscopic study of things ill.u.s.trate such separate and complete series. The cla.s.sical example for the whole theory is the psycho-physical parallelism. Psychical phenomena are not "explained" when the correlated line of material changes and the phenomena of the nervous system have been traced out. Similarly with the series of "vital" phenomena, "vital" interpretation from the point of view of the "living organism," runs parallel to, but distinct from the chemical and physical a.n.a.lyses of vital processes. But each of these parallel ways of regarding things is "true." For the current separation of the "appearance" and "nature" of things is false, since it a.s.sumes that only one of the possible ways of regarding things, _e.g._, the mechanical-causal mode of interpretation is essential, and that all the others deal only with a.s.sociated appearance.
The idea that only one or two of these series can represent the "true nature" of the phenomenon "can only be called cheap dogma." Each series is complete in itself, and every successive phase follows directly and without a break from the antecedent one, which alone explains it. In this lies the relative justification of the ever-recurring reactions to "vitalism."
This theory of Albrecht"s has all the charms and difficulties, or impossibilities, of parallelistic interpretations in general. Its validity might be discussed with reference to the particular case of psycho-physical parallelism.(104)
To make a sound basis for itself it would require first to clear up the causality problem, and to answer, or at least definitely formulate the great question whether causing (Bewirkung) is to be replaced by mere necessary sequence-for this is where it ends. The conclusion which, with regard to biological methods and ideals, seems to make all concessions to the purely mechanical mode of interpretation, is not sufficiently obvious from the premisses. If the vital series be a "real" one, we should expect that a "vitalistic" mode of interpretation, with methods and aims of its own, would be required, just as a special science of psychology is required. The a.s.sumption that each series is complete without a break, and that an all-including a.n.a.lysis of vital processes in terms of mechanical processes must ultimately be possible, is a _pet.i.tio principii_, and breaks down before the objections raised by the vitalists. The most central problem in the whole matter, namely, the relation of the causal to the teleological, has not been touched. These two concepts would, of course, not yield "parallels," but would be different points of view, which could eventually be applied to each series.
K. Camillo Schneider,(105) Privatdozent in Vienna, uses the soul, the psychical in the true sense, as the explanation of the vital. What had been thought secretly and individually by some of the vitalists already mentioned, but had, so to speak, cropped up only as the incidentally revealed reverse side of their negations of mechanism, Schneider attempts definitely to formulate into a theory. The chief merit of his book on "Vitalism" is to be found, in Chapters II. to X., in his thorough discussion of the chemical, physical, and mechanical theories along the special lines of each.
The list of critics might be added to, and the number of standpoints in opposition to mechanism greatly increased. This diversity of standpoint, and the individual way in which each independent thinker reacts from the mechanical theory shows that here, as also in regard to Darwin"s theory of selection, we have to do with a dogmatic theory and a forced simplification of phenomena, not with an objective and calm consideration of things as they are. It is a theory where _simplex_ has become _sigillum falsi_.
How all this affects the Religious Outlook.
These denials and destructive criticisms of the mechanical theory, which are now continually cropping up, lead, as must be obvious, towards a deeper conception and interpretation of reality in general, and towards a religious conception in particular. Unquestionably the most important fact in connection with them is the fresh revelation of the depth of things and of appearance, the increased recognition that our knowledge is only leading us towards mystery.
It is indeed questionable whether anything more than this can be said in regard to the problem of life, whether we ought not to content ourselves with recognising the limits of our knowledge, and reject all positive statements that go beyond these limits. For the mechanists are undoubtedly right in this, that "entelechy," "the idea of the whole," "co-operation,"
"guidance," "psychical factors," and the like, are only names for riddles, and do not in themselves const.i.tute knowledge.(106) The case here is somewhat similar to what we have already seen in connection with "antinomies." They, too, give us no positive insight into the true nature of things, but they at any rate prove to us that we have not yet understood what that is. And, just as they show us that our knowledge of the world as it appears to us can never be complete, so here it appears that we come upon inexplicabilities even within the domain accessible to our knowledge. Thus the religious conception of the world gains something here as from the antinomies, namely, a fresh proof that the world which appears to us and can be comprehended by us, proclaims its true nature and depths, but does not reveal them. Perhaps there is still another gain. For in any case the vital processes and the marvels of evolution and development are examples of the way in which physical processes are constantly subject to a peculiar guidance, which certainly cannot be explained from themselves or in terms of mechanism, organisation, and the like. All attempts to demonstrate this in detail, all "explanations" in terms of dynamic co-operation, of dominants, of ideas, or anything else, are vague, and seem to go to pieces when we try to take firm hold of them.
But the fact remains none the less.
May not this be a paradigm of the processes and development of the world at large, and even of evolution in the domain of history? Here, too, all ideas of guidance, of endeavour after an aim, &c., which philosophical study of history or religious intuition seems to find, make shipwreck against the fact that every attempt to demonstrate their nature, fails.
All these theories of influx, concursus, and so on, whether transcendental or immanent factors be employed, immediately become wooden, and never admit of verification in detail. But precisely the same is true of the dominance of the "idea," or of the "law of evolution," or of the "potential of development" in every developing organism. Yet incomprehensible and undemonstrable in detail as this "dominance" is, and completely as it may be concealed behind the play of physical causes, it is there, none the less.
CHAPTER X. AUTONOMY OF SPIRIT.
The aim of our study has been to define our att.i.tude to naturalism, and to maintain in the teeth of naturalism the validity and freedom of the religious conception of the world. This seemed to be cramped and menaced by those "reductions to simpler terms" which we have already discussed.
But one of these reductions, the most important of all, we have not yet encountered, and it remains to be dealt with now. In comparison with this one all others are relatively unimportant, and it is easy to understand how some have regarded the problem of the relations of the naturalistic and the religious outlook as beginning at this point, and have neglected everything below it. For we have now to consider the attempt of naturalism to "reduce" spirit itself to terms of nature, either to derive it from nature, or, when that is recognised as quite too confused and impossible, to make it subject to nature and her system of laws, or to similar laws, and thus to rob it of its freedom and independence, of its essential character as above nature and free from it, and to bring it down to the level of an accompanying shadow or a mere reverse side of nature. The aggressive naturalism which we have discussed has from very early times exercised itself on this point, and has instinctively and rightly felt that herein lies the kernel of the whole problem under dispute. It has for the most part concentrated its interest and its attacks upon the "immortality of the soul." But while this was often the starting-point, the nature of soul, and spirit, and consciousness in general have been brought under discussion and subjected to attacks which sought to show how vague and questionable was the reality of spirit as contrasted with the palpable, solid and indubitable reality of the outer world. Prominence was given to the fact that the spiritual side of our nature is dependent on and conditioned by the body and bodily states, the external environment, experiences and impressions. These were often the sole, and always the chief subjects of the doctrine of the vulgar naturalism. But the same is true of the naturalism of the higher order, as we described it in Chapter II. In order to acquire definite guiding principles of investigation, it makes the attempt to find the true reality of phenomena in the mechanical, corporeal, physiological processes, and to take little or no account of the co-operation, the interpolation, the general efficiency of sensation, perception, thought, or will, and to treat them as though they were a shadow and accompaniment of reality, but not as an equivalent, much less a preponderating const.i.tuent of it. Out of these fundamental principles of investigation, and out of the opposition and doubt with which the spiritual is regarded, there is compounded the current mongrel naturalism, which, without precision in its ideas, and without any great clearness or logical consequence in its views, is thoroughly imbued with the notion that that only is truly real which we can see, hear, and touch-the solid objective world of matter and energy, and that "science" begins and ends with this. As for anything outside of or beyond this, it is at most a beautiful dream of fancy, with which it is quite safe to occupy oneself as long as one clearly understands that of course it is not true. "Nature" is the only indubitable reality, and mind is but a kind of _lusus_ or _luxus naturae_, which accompanies it at some few places, like a peculiarly coloured aura or shadow, but which must, as far as reality is concerned, yield pre-eminence to "Nature" in every respect.
The religious conception is deeply and essentially antagonistic to all such attempts to range spirit, spiritual being, and the subjective world under "nature," "matter," "energy," or whatever we may call what is opposed to mind and ranked above it in reality and value. The religious conception is made up essentially of a belief in spirit, its worth and pre-eminence. It does not even seek to compare the reality and origin of spirit with anything else whatever. For all its beliefs, the most sublime and the crudest alike, conceal within them the conviction that fundamentally spirit alone has truth and reality, and that everything else is derived from it. It is a somewhat pitiful mode of procedure to direct all apologetic endeavours towards the one relatively small question of "immortality," thus following exactly the lines usually adopted by the aggressive exponents of naturalism, and thus allowing opponents to dictate the form of the questions and answers. It is quite certain that all religion which is in any way complete, includes within itself a belief in the everlastingness of our spiritual, personal nature, and its independence of the becoming or pa.s.sing away of external things. But, on the one hand, this particular question can only be settled in connection with the whole problem, and, on the other hand, it is only a fraction of the much farther-reaching belief in the reality of spirit and its superiority to nature. The very being of religion depends upon this. That it may be able to take itself seriously and regard itself as true; that all deep and pious feelings, of humility and devotion, may be cherished as genuine and as founded in truth; that it behoves it to find and experience the n.o.ble and divine in the world"s course, in history and in individual life; that the whole world of feeling with all its deep stirrings and mysteries is of all things the most real and true, and the most significant fact of existence-all these are features apart from which it is impossible to think of religion at all. But they all depend upon the reality, independence and absolute pre-eminence of spirit. Freedom and responsibility, duty, moral control and self-development, the valuation of life and our life-work according to our life"s mission and ideal aims, even according to everlasting aims, and "sub specie aeterni," the idea of the good, the true and the beautiful-all things apart from which religion cannot be thought of-all these depend upon spirit and its truth. And finally "G.o.d is Spirit": religion cannot represent, or conceive, or possess its own highest good and supreme idea, except by thinking in terms of the highest a.n.a.logies of what it knows in itself as spiritual being and reality. If spirit is not real and above all other realities; if it is derivable, subordinate and dependent, it is impossible to think of anything whatever to which the name of "G.o.d" can be given. And this is as true of the refined speculations of the pantheistic poetic religions, as of the idea of G.o.d in simple piety. The interest of religion as against the claims of naturalism includes all this. And it would be doing the cause of religion sorry service to extract from this whole some isolated question to which the mood of the time or traditional custom has given prominence. Our task must be to show that religion maintains its validity and freedom because of the truth and independence of spirit and its superiority to nature.
It is, of course, impossible to give an exhaustive treatment of this problem in a short study like this. The answer to this question would include the whole range of mental science with all its parts and branches.
Mental science, from logic and epistemology up to and including the moral and aesthetic sciences, proves by its very existence, and by the fact that it cannot be reduced to terms of natural science, that spirit can neither be derived from nor a.n.a.lysed into anything else. And it is only when we have mastered all this that we can say how far and how strongly knowledge and known realities corroborate religion and its great conclusions as to spirit and spiritual existence, how they reinforce it and admit its validity and freedom. Since this is so, all isolated and particular endeavours in this direction can only be a prelude or introduction, and a more or less arbitrary selection from the relevant material of facts and ideas. And nothing more than this is aimed at in the following pages.
Naturalistic Attacks on the Autonomy of the Spiritual.
The attacks that have been made by naturalism upon the independence and freedom of the spiritual are so familiar to every one-even from school days-through books of the type of Buchner"s "Kraft und Stoff," and Haeckel"s "The Riddle of the Universe," and other half or wholly materialistic popular dogmatics, that it is unnecessary to enter into any detail. Very little that is new has been added in this connection to the attack made by Plato on himself in the "Phaedo" through Simmias and Kebes.
It is only apparently that the modern attacks have become more serious through the deepened knowledge of natural science. At all times they have been as serious and as significant as possible, and the religious and every other idealistic conception of the universe has always suffered from them. It is plain that here, if anywhere, "faith goes against appearances," and that in the last resource we have to postulate free moral resolution, the will to believe, the desire for the ideal, for freedom, and for the eternity of the spirit, and the confidence of the spirit in itself. All this is, or at least ought to be, self-evident and generally admitted.
Let us once more take a brief survey of the reasons on the other side and arrange them in order.
That nature is everything and spirit very little seems to follow from a very simple circ.u.mstance. There are whole worlds of purely natural and corporeal existence without mind, sensation, or consciousness, which, quite untroubled by their absence, simply exist according to the everlasting laws of matter and energy. But nowhere do we find spirit or mind without a material basis. All that is psychical occurs in connection with a physical being, and with relatively few physical beings. Spirit seems wholly bound up with and dependent upon the states, development, and conditions of material being. With the body of living beings there arises what we call "soul"; with the body it grows, gains content, changes, matures, ages, and disappears. According as the body is const.i.tuted and composed, as it is influenced by heredity, race, and selection, by nutrition, mode of life, climate, and other circ.u.mstances, there are developed in a hundred different ways what we call the natural disposition or character, inclinations, virtues or vices, pa.s.sions or temperaments.
Even the names given to the different temperaments emphasise this dependence of what is innermost in us, the deepest tendencies of our being, on the bodily organisation and the nature of its physiological const.i.tution. The man whose blood flows easily and freely is called sanguine, and the melancholic is the victim of his liver. According as our organs are good or bad, function freely or sluggishly, our mood rises or sinks, we are bold or cowardly, languid or impetuous, and enthusiasm is often enough only a peculiar name for a state which, physiologically expressed, might be called alcoholic poisoning. There is one soul in the sound body, another in the sickly. Fever, and the impotence of the soul against it, made Holbach a materialist. If the brain be diseased, that marvellous order of psychical processes which we call reasoning is broken; the "soul" is wholly or partly eliminated; it fades away, or becomes nothing more than a confused disconnected medley of images and desires.
Even artificial interference with, and changes in the bodily organisation react upon the mind. The removal of the thyroid gland may result in idiocy. Castration not only prevents the "breaking" of the voice in the Sistine choristers, it damps the fires of life to dulness, and makes of the impetuous Abelard a comfortable discursive father-confessor. The mind is bound up almost piece by piece with its material basis. Through the "localisation" of psychic processes in the particular parts of the brain, naturalism has enormously strengthened the impression that existed even among the ancients, that sensation and imagination are nothing more than, let us say, what the note is to a tightly stretched string. Cerebrum and cerebellum are regarded as the seats of different psychic processes. The secret of the higher processes is believed to be hidden in the grey matter of the cortex of the cerebrum. We seek and find in the various lobes and convolutions of the brain the "centres" for the different capacities, the power of sight, of smell, of moving the arms, of moving the legs, of a.s.sociating ideas, of co-ordinated speech, and so on. When brain and spinal cord are injured or removed piece by piece from a pigeon or a frog, it seems as if the "soul" were eliminated piece by piece,-the capacity for spontaneous free co-ordination, for voluntary action, for the various sense-impressions, and so on from the higher to the lower. It has even been maintained that the different feelings and perceptions which are gradually acquired can be apportioned among the individual cells of the brain in which they are localised, and the thought-processes, the a.s.sociations of percepts, the origin of consecutive ideas, the rapid and easy recalling of memory-images, and the process of voluntary control, of instincts, can be explained as due to the "gradual laying down of nerve-paths" between the different centres and areas of localisation in the brain. All this seems to refute utterly the old belief in the unity and personality of the soul. It is different in youth and in age, and indeed varies continually. It is the ever-varied harmony of the notes of all the strings which are represented by the fibres and ganglion-cells of the nerve-substance. It apparently can not only be completely confused and brought to disharmony, but it may be halved and divided. An almost terrifying impression was produced when Trembley in 1740 made the experiment of cutting a "hydra" in two, and showed that each of the halves became a complete animal, so that obviously each of the two halves of the soul grew into a new hydra-soul. And Trembley"s hydra was only the precursor of all the cut-up worms, of the frogs, birds, and guinea-pigs that have been beheaded, or have had their brain removed, or their nerves cut, and have furnished further examples of this divisibility of "souls."
If the independence of the spiritual is thus shown to be a vain a.s.sumption, the alleged difference between the animal and the human Psyche is much more so. Not from the days of Darwinism alone, but from the very beginning, naturalism has opposed this claim to distinctiveness. But it is due to Darwinism that the fundamental similarity of the psychical in man and animals has come to be regarded as almost self-evident. The mental organisation of man, as well as his corporeal organisation, is traced back through gradual stages to animal antecedents, and in thus tracing it there are two favourite methods of procedure, which are, however, apt to be mutually destructive.
On the one hand, some naturalists regard the animal anthropomorphically, insist on its likeness to man, discovering and extolling, not without emotion, all the higher and n.o.bler possessions of the human mind, intellectual capacities, reason, reflection, synthesis, fancy, the power of forming ideas and judgments, of drawing conclusions and learning from experience, besides will in the true sense, ethical, social and political capacities, aesthetic perceptions, and even fits of religion in elephants, apes, dogs, down even to ants and bees, and these naturalists reject old-fashioned explanations in terms of instinct, and find the highest already contained in the lowest. Those of another school are inclined to regard man theriomorphically, to insist on his likeness to animals, explaining reason in terms of perception and sensation, deriving will from impulse and desire, and ethical and aesthetic valuations from physiological antecedents and purely animal psychological processes, thus, in short, seeking to find the lowest in the highest. (We have already met with an a.n.a.logous instance of a similarly fallacious double-play on parallel lines.) So it comes about that both the origin and the development of the psychical and spiritual seem to be satisfactorily cleared up and explained, and at the same time a new proof is adduced for its dependence upon the physical. For what is true of all other parts of the organisation, of the building up and perfecting of every member and every system of organs, the bony skeleton, the circulatory system, the alimentary ca.n.a.l, that they can be referred back to very simple beginnings, and that their evolution may be traced through all its stages-is equally true of the nervous system in general and of the brain in particular. It increases more and more in volume and in intricacy of structure, it expands the cranial cavity and diversifies its convolutions.
And the more it grows, and the more complex it becomes, the more do the mental capacities increase in perfection, so that here again it seems once more apparent that the psychical is an accompaniment and result of the physical.
Popular naturalism usually stops short here, and contents itself with half-truths and inconsequences, for it navely admits that psychical processes, sensation, perception, will, have a real influence upon the physical, and, not perceiving how much the admission involves, it does not trouble itself over the fact that, for instance in the so-called voluntary movements of the body, in ordinary behaviour, the psychical, and the will, in particular, is capable of real effect, and can move hand and foot and the whole body, and thus has a real reciprocal relation with the physical.
This form of popular naturalism sometimes amuses itself with a.s.suming a psychical inwardness even in non-living matter, and admitting the co-operation of psychical motives even in regard to it.
But it is far otherwise with naturalism in the strict sense, which takes its fundamental principles and its method of investigation seriously. It is aware that such half-and-half measures interrupt the continuity of the system at the most decisive point. And therefore with the greatest determination it repeats along psychological lines the same kind of treatment that it has previously sought to apply to biological phenomena: the corporeal must form a sequence of phenomena complete in itself and not broken into from without. All processes of movement, all that looks as if it happened "through our will," through a resolve due to the intervention of a psychical motive, every flush of shame that reddens the cheek, every stroke executed by the hand, every sound-wave caused by tongue and lips, must be the result of conditions of stimulation and tension in the energy of the body itself.
This is the meaning of all those psycho-physical experiments that have been carried on with so much ingenuity and persistence (usually a.s.sociated with attempts to explain vital phenomena in terms of mechanism). First, they attempt to interpret the expressions of will, feeling and need, the spontaneous activities and movements of the lowest forms of life-protists-as "pure reflexes," as processes which take place in obedience to stimuli, and thus are ultimately due to chemical and physical influences and causes without the intervention of a psychical motive; and, secondly, when this has been apparently or really achieved, the theory of irritability and reflex mechanism is pushed from below upwards, until even the most intricate and complex movements and operations of our own body, which we have wrongly distinguished as acts or behaviour from mere processes of stimulation, are finally recognised as reflexes and liberations due to stimuli. Some stimulus or other, from light or sound or something else, is, according to this theory, conducted to the nervous centre, the ganglion, the spinal cord, the cerebellum or the cerebrum.