In conclusion, we can now more closely consider the question of the difference between the conscious and the unconscious will. A will, the content of which is formed by an unconscious idea, could at the most be consciously perceived according to its empty form of volition, and acts of will of that kind could then at the most only be discriminated by consciousness as different in degree; on the other hand, it can no longer be perceived by consciousness as this specific will, since its specific nature is only determined by its content. Accordingly, for such a will the application of the word "conscious" is unconditionally excluded, as in no case can more be said than that this specific will becomes conscious. Moreover, experience also teaches us that we know so much the less of a will the fewer the ideas or feelings accompanying it which reach the cerebral consciousness. Accordingly, it almost seems as if will as such were not generally accessible to consciousness, but became so only through its marriage with the idea. (This is proved, in fact, in Chap. iii. C.) However that may be, we can now assert that an unconscious will is a will with unconscious idea as content, for a will with conscious idea as content will always be conscious to us. If, in saying this, the distinction between conscious and unconscious will is only traced back to the equally difficult distinction between conscious and unconscious idea, yet an essential simplification of the problem is thereby obtained.

V.

THE UNCONSCIOUS IN REFLEX ACTIONS.

"AT the present time those actions are called reflex in which the existing stimulus does not directly affect either a contractile tissue or a motor nerve, but a nerve which imparts its state of excitement to a central organ, whereupon, through the mediation of the latter, the stimulus overflows on to motor nerves, and then for the first time is made apparent by muscular movements."1 This explanation seems to me as good a one as the physiologists are able to give, and no qualification of the same can be found which does not exclude certain classes of reflex action generally recognised by this name; and yet it is easy to see that it is much wider than physiology intends, since all movements and actions find a place among them, whose antecedent is not a thought which has arisen spontaneously in the brain, but is directly or indirectly a sense-impression. To pursue further this gradual passage of the lowest reflex movements into conscious voluntary actions, we must examine various examples.

If a freshly excised frog's heart, which pulsates slowly, be irritated by the prick of a needle, there arises independently of the rhythm of the beat a systole (contraction) in the normal succession of the parts. Before the complete extinction of irritability a time occurs when the

1 Wagner's Handwörterbuch der Physiologie, vol. ii. p. 542, article "Nervous Physiology," by Volk mann. On the historical develop. ment of the notion of reflex movement, and for an estimate of the views

of earlier investigators, which often come very near the truth, compare also the excellent memoir of J. W. Arnold: "The Doctrine of Reflex Functions."

irritation is only succeeded by a local contraction of decreasing extent. If the heart be divided when it is still powerful, but in such a way that there remain connecting portions between the parts, stimulation of the one part, in which a ganglion is contained in the muscular substance, produces contraction of both parts; on the other hand, irritation of the other part, which contains no ganglion, is only succeeded by local contraction. It follows from this, that the normal systole sequent on stimulation. is no simple phenomenon of the stimulus of a contractile tissue, but a reflex movement mediated by the embedded ganglia. Other experiments, e.g., the division of the spinal cord by small cross sections, &c., render it probable that any nerve-centre may effect reflex actions. The more this nerve-centre is developed the higher is the degree of propriety and adroitness in complicated movements exhibited in its reflex actions. Volkmann says (Hwb. ii. 545): "When different muscles are combined to produce a reflex movement, whether synchronous or successive, the combination is always mechanically appropriate. I mean, the simultaneously active muscles support one another, e.g., in producing a flexure, and those which are active in succession unite in the judicious continuation and completion of the already commenced movement. If a decapitated frog in an extended position be stimulated in the hind leg sufficiently powerfully, the flexors and adductors of both legs first of all act in combination, next the legs are drawn towards the body, the extensors. are combined for joint extension, and the total result is a more or less regular actual movement, whether of swimming or leaping.

66 In many cases the reflectorial movements have not only the character of fitness, but even a certain dash of intention. Young dogs whose cerebrum and cerebellum I had destroyed, sparing the medulla oblongata, when I took them roughly by the ears tried to get rid of my hand with the fore-paw. One often sees decapitated frogs rub

a violently filliped part of the skin (only possible by an alternating play of the antagonists), and tortoises, which are injured after decapitation, withdraw into their carapace." The medulla oblongata, as the most developed nerve-centre after the brain, is also that which effects the most complicated reflex movements, as, e.g., respiration with its modifications: sobbing, sighing, laughing, crying, coughing; also sneezing on irritation of the nasal membrane, swallowing, and vomiting on gentle pressure (by a morsel) or tickling of the throat and palate; laughing ensues on tickling the external skin, coughing on irritation of the larynx.

Very important for the whole life of man, and indicative of much more complicated events in the central organs, are the reflex movements called forth by sense-perceptions; certainly a class of phenomena to which physiology has not yet given sufficient attention, because they can only be studied with the whole living body, and partly only psychologically in one's own person. It is, however, manifest that this mode of investigation has great advantages over that on mutilated corpses or animals with their brains removed, since in organisms which have just suffered death, or undergone the severest operations, or have been treated with strychnine, one can by no means assume a normal capacity of reacting on the part of the lower central organs, which stand in such direct correspondence with the destroyed parts. Moreover, in decapitated animals the medulla oblongata and the large cerebral ganglia, which probably should be reckoned to the spinal cord, or at least not to the brain, have also been removed. All this sufficiently explains the purposeless character of the reflex movements in some of these experiments, where one is unable to eliminate the pathological elements.

The proximate reflex movements called forth by a senseimpression consist in this, that the particular sense-organ is brought into the position, tension, &c., requisite for clear

VOL. I.

I

perception. In touch there arises a movement to and fro of the finger; in taste, secretion of saliva and movement to and fro of the sapid matter in the mouth; in smelling, dilatation of the nostrils and short, quick inspirations; in hearing, tension of the tympanic membrane and movements of the ears and head; in vision, convergence of both optic axes towards the point of greatest stimulation, accommodation of the lens for distance, and of the iris to the intensity of light. All these movements, with the exception of the last named, can also be executed voluntarily, but only by means of the idea of the altered sense-impression; only with difficulty or not at all by the direct idea of the movements. E.g., when the investigating oculist holds up his finger as a mark for the patient and bids him look up towards the right, there frequently occur the most distorted movements of the eyes and eyelids, but not the one desired. With enhanced vividness of the impression, the head, arms, and whole body not seldom take involuntary part in these reflex actions. Further, through the medium of the ear reflex movements are set up in the organs of speech, for, as is well known, children and animals learn to talk in consequence of the involuntary impulse which compels them to reproduce what has been heard. The like occurs in the catching of melodies, where the phenomenon is more easily observed, and in adults also. Without this reflexion it would be impossible to train birds to whistle tunes. The reflex compulsion to utter words one is accustomed to hear spoken may even be observed in our own thinking. Here, according to a process exemplified in a still higher degree in the production of dreamimages and hallucinations, the thought of the word which is not yet an object of sense causes a centrifugal current of innervation towards the auditory nerve, as the reflex consequence of which a centripetal current brings back the auditory sensation of the word, and this calls forth in the organs of speech the reflex movements of the loud