That which we know psychologically of suggestion lies, on the one hand, in the sphere of consciousness, and in the observed motor, vasomotor, secretory, and similar reactions, on the other hand. But how does the matter stand when viewed in a physiological light? What takes place physiologically in those hypoconceived mechanisms which connect the suggestion with its action, and into which hypnosis supplies us with a fleeting, incomplete, merely subjective, and therefore psychological insight by means of sporadic associations of superconceived processes, with the contents of the hypoconsciousness?

Meynert, Wernicke, Munk, Exner, Sachs, and others, have attempted, on the evidence of the results obtained in the anatomy of the brain, to form an idea of the mechanism of the neurokymes of the brain. The synthetic introspection of the latter represents consciousness. The contents of consciousness must always remain fragmentary to us, for the reasons already given. Physiology alone can lead to a doctrine of the mechanism of the mind, as it can supply a complete chain of argument. It is true that we do not possess the key to the mechanisms of life; but we can attempt to explain it, notwithstanding, biologically and approximately, with the help of conclusions by analogy. In my opinion, Oscar Vogt has made the best attempt to explain the dynamism of the brain. I propose to give extracts from his explanation.

Oscar Vogt's Hypothetical Views 1 on the Nature and Psycho-logical Import of Hypnotism. - Vogt, in his excellent work, calls the massed mechanism of the brain, which corresponds to a psychological process, "constellation." This constellation is the product of conscious and unconscious (hypoconscious) processes. It influences both the quality and the intensity of the central excitability. It can even exceed in importance, in virtue of its assimilating activity, the peripheral stimulation for the quality of the central excitability. The apparent freedom of will is based on this sort of thing.

Vogt accepts parallelism terminologically, but interprets it in the light of monistic identity, and not of dualism. Peripheral stimuli of too powerful a nature produce unconsciousness instead of hyperaesthetic phenomena of consciousness in response to a cutting off caused by vasomotor changes. Our qualitative and quantitative psychological powers of differentiating are based on a passive becoming conscious of physiological differences (in this, for example, Vogt accepts the identity theory).

1 Oscar Vogt: "Contributions to our Knowledge of the Nature and Psycho- logical Import of Hypnotism," Zeitschrift fur llypnotismus, 1895-1896 (Leipzig: Ambrosius Barth).

Wherever phenomena of consciousness appear, these tend at once to become synthetic processes, so that man from his youth upward already possesses complex psychical phenomena. The synchronous irritability of the individual elements of the contents of consciousness leads to their association, which becomes fixed by habit. A primary degree of fixation is necessary for a psychological synthesis. Further fixation causes recognition, and still further fixation causes associative reproduction capability. There are simultaneous and consecutive associations.

Wundt uses the term "assimilation" for the fact that in the whole psychological area of the memory of man only those sensations occur which are associated by the co-irritation of the impressions of memory, and not isolated sensations in general. For this reason new elements in alternating sequence are intermingled with the same conception at each repetition, and the conception is in consequence never quite identical - e.g., the conception of a rose.

The principle of psychical synthesis is thus that complete complexes of elements of consciousness are never bound together or intermingled, but only the individual elements. In order that it can be reproduced, an association must therefore be fixed, in so far that it can be excited in its entirety from each of its elements.

Vivid pictures of the imagination are qualitatively much more nearly related to sensations in highly dissociable persons.

The intensity of a conception depends on the intensity of the excitability of the individual elements, while its clearness (Lehmann) depends on the extent of the same - i.e., on the number of elements excited at the same time. These are therefore different things.

Next, psychical energy of an individual forms a constant under constant conditions of nutrition. This may be taken to mean, for example, that one cannot suffer intensely from toothache, and at the same time follow a play intently. The intensity of one process necessitates a weakening of that of others.

Associations move in accordance with the law of energy, in the order arranged by habit, always in the direction of least resistance. When this appears not to be the case, the cause is hypoconceived.

Vogt explains attention as follows: The center whose metabolism is increasing receives functional stimuli from the centers whose metabolism is decreasing. As a matter of fact, vastly more peripheral stimuli for the senses travel up to the brain than are recognized (felt). These numerous neurokymes, arriving in the brain, are all deflected to the situation where a marked excitability is taking place, and the latter becomes thereby increased. If two centers are equally excited, the neurokymes arriving are divided correspondingly. If a certain center (A) is alone excited, and a neurokyme from without arrives suddenly at a second center (B), exciting it intensely, all the neurokymes will be deflected to B, and the excitability of A will diminish. In this way the attention will be diverted from A to B. Illusions can be produced in a similar manner. For example, suppose that a person is expecting some one. A sound is heard, and this person believes that he can recognize the footsteps of the person expected. The marked expectation has so strengthened the impression of the memory of the well-known footsteps that it drowns the real noise with which it is assimilated, and thus causes the illusion.

These considerations induced Vogt to revert to the old views of Schiff, which state that deflections of the energy of stimulation cause neurodynamic inhibitions, and these are to be regarded as compensation phenomena for conduction taking place in other directions. In this way it is not only the situation of the stimulation, but also its intensity, which influences the quality of the action. Freusberg found, by way of example, that a mild stimulus to the penis of a dog produces an erection, but a stronger stimulus to the erected penis leads to relaxation, but causes at the same time a reflex excitation of a leg move-ment. This is due to a part of the stronger congested energy of stimulation being radiated from the erection center, and reaching in this way the center for the reflex excitation of the leg. Since the latter is more strongly excitable, all the neuro-kymes then travel to it, and the penis in consequence relaxes. A number of similar facts support Vogt's view that the increased intensity of attention is referred to an opening up of a path by attracted neurokymes.

Vogt further adopts Hering's view that all psychical phenomena, movements included, are caused by peripheral stimuli, and that there is no such thing as pure centrogenous movement. Bering showed, for example, that a decapitated frog becomes completely motionless as soon as one divides all the posterior spinal roots. But the direction in which the peripheral neurokymes travel to the central nervous system naturally depends on their constellation for the moment.

Dissociations are constellations deflected from the usual normal condition during waking. Here one meets with all sorts of transitions, from a mild warping of judgment to dreaming.

The diminution of excitability, which we call inhibition, takes the shape normally of a change of nutrition.

A lessening of metabolism causes exhaustion, so that the dissimilation overbalances the assimilation. Anaemia of the brain, which is always associated with sleep, causes a similar process, but is introduced by tiring (dissociation). In a dissociated dream the neurokyme is congested in one center, as a result actually of this anaemia. This prevents the awakening of associated contra-conceptions, and increases the intensity of the dream.