1 It can hardly be necessary to call to mind that the determination of the “Alogical” and “Logical,” here deduced from the nature of the two principles “Will” and “unconscious intuitive Idea,” had already been proved by the inductive path. The chapter on the Misery of Existence, namely, had inductively proved that the existence of this world is worse than would be its non-existence; that therefore the “That” of the world, or its existence, must owe its origin to an irrational or alogical principle, but at the same time also that this irrational principle, which proceeds to make the world into a wretched one, is volition. On the other hand, it has been shown by all the preceding investigations that the “What” of the world is contrived most judiciously and wisely, and thereby points to the action of a wise and logical principle, which we have perceived in its manifestation to be unconscious intuitive presentation. It seemed to me expedient to show here once more that the contrary course also leads to the understanding of the Whole, i.e., that from the very nature of the pyschical elementary functions “willing and perceiving,” expanded into attributes of the All-One, follows atonce the alogical and logical character of the same, because in this manner the organic connection of all the terms in the traversed circle of thought becomes fay more conspicuous.
APPENDIX.
THE PHYSIOLOGY OF THE NERVE-CENTRES.
I .
Introduction.—The deep obscurity in which the functions of the central organs of the nervous system were wrapt until a few generations ago, has in the course of the present century been cleared up at many points, and in the last decennium these points, illuminated by the light of knowledge, have so increased that a certain comprehension of the facts as a connected whole is now within our reach. However conscious the possessors of this knowledge may still be of its incompleteness and superficiality, it must yet be welcomed as a first foundation of the physiology of the central organs, and is already in a position to furnish hints in different directions, which are of value partly for the psychological, partly for the natural-philosophical elaboration of experience.
Unfortunately, until a short time ago there existed no work which collected into a clear whole, and thereby made accessible to wider circles the communications with respect to this particular branch of physiology that are scattered in scientific books and journals. Perhaps Maudsley in the first physiological part of his “Physiology and Pathology of Mind” had come nearest to the mark; however, the second edition of this work bears the remote date 1868, and cannot therefore contain the results of the most recent progress of science.1 On the other hand, the “Grundzüge der physiologischen Psychologie” of Professor Wilhelm Wundt (Leipzig: Engelmann, 1873 and 1874) fulfil the function of a compendium in an eminent degree, and along with a physiology of the sense-preceptions (in the 2d and 3d secs.) offer substantially a physiology of the nervous system, and specially of its central organs (in the 1st, 4th, and 5th secs.) To be sure this compendium, just on account of the wealth and the concentration of its contents, is more a book for study and for reference than for the general reader, and the sobriety of the elaboration of the mass of material amounts almost to dryness, by the author avoiding with almost painful anxiety every flight of thought beyond the empirical data. Of unfavourable influence in this direction was evidently the influence of the dry and unfruitful Herbartian philosophy, by which Wundt is unmistakably affected, notwithstanding his frequent criticism of the fundamental views of Herbart. The doctrine of the emotions and impulses (in chap. xx.) loses almost all value by this dependence on Herbart and by the retention of his error, “That it is not the emotions which govern the ideas, but that the emotions rather spring from the ideas themselves” (p. 818), or that “all manifestations of will arise from ideas” (and those conscious ones) (p. 622). This perverse conception of course prevents him from at all comprehending the unconscious life of the feelings and impulses, its connection with the inmost core of individuality, the character, and the thoroughgoing dependence of the intellectual life both in the healthy and in the morbid condition on the sphere of the will. But just that which is wanting in Wundt is with Maudsley a regulating fundamental idea of his conception of the healthy and morbid life of the mind, and he attains by means of it the most surprising results.
Thus Wundt and Maudsley are complementary to one another. To the richer and more precise material of the former the latter brings the fine psychological observation of a tried mental physician, and by his often ingenious side-remarks offers an abundance of valuable stimulus to thought. The fundamental importance for the conscious of the unconscious psychical life, the thorough dependence of the former on the latter, as well as the primacy of the will, is with Maudsley a firm conviction. As predecessors in respect of the knowledge of unconscious mental life, he cites, in his unacquaintance with German philosophy, hardly any one but Hamilton, Carlyle, and Jean Paul Friedrich Richter.
For Wundt, who, in his earlier studies on the genesis of sense-perception, had independently reached the theory of unconscious inferences, the hypothesis of Herbart that the will results from the dynamic of ideas was fraught with serious consequences, in that he was induced thereby to limit the scope of his own earlier doctrine. And undoubtedly the theory of unconscious inference cannot but appear a very venturesome and doubtful hypothesis when completely isolated and arbitrarily limited by the denial of unconscious mental life in all other directions. Nevertheless Wundt’s restriction of the doctrine of unconscious inference (which, according to his own statement on p. 708, is thoroughly accepted by the more recent “Psychology,” so far as it does not take a Nativistic direction) merely amounts to this, that the unconscious connection of those moments which we reproduce in discursive logical form is not to be regarded as a discursive one (which I myself have always and everywhere emphatically asserted); and only because Wundt does not observe that the form of Logic in and of itself is anything but discursive, but first becomes so through reception into the form of consciousness, only for that reason does the acknowledgment of a logical connection in the unconscious genesis of perception appear to him hazardous (cp. pp. 424, 460–461, 637, 708–711). The error of Wundt, in refusing to acknowledge the essence of the logical save in the discursive form of reflection, seems to stand in close connection with his other erroneous opinion, that consciousness also only consists in the form of discursive reflection, i.e., in the connection between ideas separated in time, brought about by memory and reflection (cp. pp. 825–827, 829, 837). It is, however, not evident why a conscious centre should not be conceived which once in a lifetime, and then never again, has a perception, and yet retains this in full clearness of consciousness. Whether this perception leaves behind a memorial trace, whether this trace suffices to lead to reproduction on renewed excitement, and whether the intelligence of the organ suffices to recognise this reproduction as such (i.e., as memory), all that, is for the consciousness of the first perception entirely indifferent and without influence. Wundt thus mistakes in two directions the derived and secondary character of conscious reflection. In the first place, he fails to see that all discursiveness of conscious ideation is composed of single acts of consciousness, each of which possesses the intuitive evidence of sense; and, secondly, that all that is logical in the discursive sequence rests on the implicit logical connection of the moments of unconscious intuition. By taking as the type of consciousness in general his cerebral consciousness in the form most familiar to him of discursive reflection, without going back to its genetic elements, Wundt lapses into false conclusions on two sides; he denies the character of the logical as of consciousness when he misses the characteristics of discursive reflection.
These preliminary remarks may suffice to prove that even the two best books which we possess for acquiring an insight into the physiology of the central organs of the nervous system, taken singly, do not meet the wants of the layman, whilst to treat them as complementary requires a tolerable amount of labour and independent criticism. I think therefore that the following att
empt to discuss the most important points of our present knowledge, in all brevity, and leaving on one side all anatomical and physiological detail, will not be unwelcome to wider circles of the scientifically educated public.
2. Nerve-Fibre and Ganglion-Cell .—All the nervous elements of the organism are divisible into two clearly distinguishable kinds—conducting fibres and ganglionic cells. When the organism is intact, the conducting fibres are not determined to isolated, independent action, but merely serve to propagate or transfer a stimulus: (1.) From the peripheral sense-organs to ganglionic cells; (2.) from ganglionic cells to bundles of muscular fibres or secreting membranes; (3.) from one ganglionic cell to another. They thus serve to connect periphery and centre, or to unite several centres. The ganglionic cells, on the other hand, exercise the central functions; they receive the impulses propagated from the periphery, independently modify the same, and either neutralise them by their internal resistance, or are determined to a partial liberation of their reserved force, which then leads to peripheral actions by shorter or longer circuits and by centrifugal paths. The ganglionic cells, moreover, influence the nutrition of the nerve-fibres which proceed from them; nerves severed from their centres of innervation become atrophied (Wundt, p. 107).
But now it would not be correct so to conceive the differentiation as if the conducting elements were only passive translators, the ganglionic cells only active organs; the conducting fibres also possess their own activity, and also the grey nerve-substance made up of ganglionic cells may serve to propagate stimuli. Only because the path of resistance in the nerve-fibre is relatively much smaller than in the ganglionic cell is it more suited for conduction than the latter; and only because in the ganglion-cell the stored-up force is much greater than in the nerve-fibre is it more fitted than the latter for active operations. Until the transferred excitement is extinguished through the resistance on conduction every stimulus is also propagated in the grey matter, unless the energy therein contained can be discharged in another direction, where the path of resistance is less. Thus, e.g., the grey matter of the spinal cord after section of the white strands consisting of conducting fibres is unmistakably capable of the propagation of not too feeble stimuli; and the circumstance that with often-repeated conduction in a particular direction the nerve-substance adapts itself to this function, thus the resistance is diminished by habit, makes possible the phenomenon so important for the existence of the organism of the spontaneous compensation of disturbances by the vicarious function, not only of other plexi of fibres, but also even of the grey matter (Wundt, p. 271).
The molecular accommodation of nervous matter to the work most frequently thrust upon it also makes it explicable why the nerve-fibres that are in connection with the organs of sense are most exercised in centripetal, the fibres ending in muscles, on the other hand, most in centrifugal conduction, and meet with less resistance in the corresponding direction. That they do not under normal circumstances conduct in the reverse direction is in any case not provable, since we have no means of making the effect perceptible, if such a conduction takes place. In motor nerves the already-mentioned dependence of the nutritive condition on the corresponding ganglion cells, in sensory nerves the centrifugal current of innervation of attention and the central mode of origin of illusions of the senses, tells, however, for the existence of such opposite nerve currents. However, these reversed nervous currents are in any case of another constitution and form in their vibrations than the normal ones, and since the adaptation and customary diminution of the path of resistance has always reference only to one particular kind of stimulus, the same nerve may very well be employed in the centrifugal conduction of this and the centripetal propagation of that vibration, whilst it opposes considerable resistance to the particular conduction in the opposite sense. That for the rest this resistance also is not insurmountable has been shown by the experiments of Philipeaux and Vulpian, in which they succeeded in forming a union between the cut ends of neighbouring motor and sensory nerves, and in thereby obtaining a considerable inversion of the direction of function (Wundt, p. 227). The experiment proves beyond a doubt that the most important thing for the nervous process is the form of vibration, which is determined by the peripheral and central end-organs and handed over to the fibre, and that there can henceforth be no more talk of “specific energies” of nerves in the sense of an absolute immutability. When, on the other hand, Wundt grants (p. 361 ff.) that exercise in processes of a particular form of vibration and direction of propagation is able to impregnate nervous matter with such a molecular disposition “that every disturbance of the molecular equilibrium that occurs calls forth this particular mode of motion;” when further he is obliged to admit that this adaptation is only partly individually acquired, but rests in the main on an innate, inherited predisposition, it is not obvious why the older expression “specific energy” should not be also further retained in the revised modern sense; at the most, one might convert it into the other: “specific disposition.”
This “specific disposition” becomes an actual “energy” by representing not merely a diminution of the resistance of the path to a particular form of vibration, but, at the same time, a certain tension or potential energy, which with given stimuli is liberated as living force or energy of motion. Thus the work which, e.g., the galvanised motor nerve-fibre performs in preparing a muscular contraction is by no means a mere propagation of the received energy in unchanged form, but it is an effect from its own store of force, for whose liberation the stimulus only gives the external impulse. But now without an internal regulation any stimulus which oversteps the threshold would suffice to discharge the whole force stored up in the nerve-fibre; the reaction would be violent, and the nerve would for a long time be incapable of the repetition of a similar performance. In the mechanism of the nerve, therefore, along with the exciting potencies inhibitory ones must also be inserted, which help to fix the threshold-value of the stimulus, and to limit the discharge of nerve-fibre according to intensity and duration. If the curve of contraction of a stimulated frog’s thigh be graphically represented on a vibrating pendulum, which renders perceptible to the senses the course of the reaction, there first occurs a well-marked rise, which illustrates the growing predominance of the exciting potencies, but then a quick descent, which terminates in a depression below the level of zero. After this transitory predominance of the inhibitory influences, the excitement dies away in weaker waves (Wundt, pp. 247–253). The more capable of performance the nerve is, the greater are not only its exciting, but also its inhibitory powers; the exhaustion is shown in still higher degree in the diminution of the inhibitory influences (whereby especially the duration of the reaction is prolonged) than in diminished strength of the reaction. The difference of the reaction on weak and strong stimuli is less in the exhausted than in the fresh nerve.—An increase of irritability results with quickly succeeding repetition of the same stimulus, when the impressions are in a certain measure added together.
Quite analogously, only in changed relations of intensity are the processes set up in the ganglion-cell. One is able to make a comparison between them by causing the same scale of stimuli to act at one time directly on the motor nerve, at another time on the sensory nerves of the same half of the body issuing at the same height of the spinal cord. Ganglion-cell and nerve-fibre are related to one another pretty much as a boiler with a valve not easily to be moved to one furnished with a valve moving with facility. From the latter the steam more easily escapes because with less tension, whilst with the former the valve is only opened by vapours of greater tension, thus also streaming out with greater force (Wundt, p. 268). Because the ganglion-cell offers a far greater resistance than the nerve, it absorbs stimuli which call forth considerable reactions on direct application to the nerves; the threshold of stimulation is thus raised. In the same way, also, above the threshold of stimulation the period of latent stimulation is longer, because greater resistances, stronger inhibitory potencies must
be overcome. If, on the other hand, the reaction has once occurred, the greater store of energy of the ganglion-cell discharges also a greater energy, i.e., the reaction is stronger with similar stimuli, and is, moreover, even with such a choice of the stimuli that the heights of contraction become equal, of longer duration (Wundt, p. 261 ff.) The summation of rapidly succeeding similar stimuli is still more perceptible and of still greater importance in the ganglion-cell than in the nerve. The aggregate activity of rhythmically recurrent stimuli, which taken singly lie below the threshold of stimulation, is the key to the understanding of the genesis of most sensations of moderate strength, which are almost all of them due to the combination of stimuli, each one of which would by itself (as, e.g., an isolated wave of sound in a tone) be ineffectual. The condition of exhaustion, too, is manifested altogether in the same way as in the nerve; a special form of exhaustion is, however, that due to nerve-poisons (e.g., for the ganglion-cells of the spinal cord by strychnine). Although the duration of latent stimulation is increased in poisoning by strychnine, yet the irritability is considerably enhanced (even beyond the irritability of the motor nerve), and every stimulus acts in the same manner as with the healthy ganglion-cell a whole series of similar stimuli; all reactions become stronger and more persistent, vehement even to convulsion; small and great stimuli soon call forth reactions of like strength, and finally, the spinal cord reacts on every stimulus with convulsions (Wundt, pp. 263–264).
Philosophy of the Unconscious Page 100
