ASSOCIATION
The elements of our consciousness, as the foregoing discussion has taught us, stand in general combinations with each other. Even where objective impressions lack steady combinations, we are accustomed to construct such by means of subjective sensations and feelings. The single beats of a row on the metronome are as such isolated, but we combine them into a rhythmical whole by means of our feelings of strain and relaxation, and by means of weak accompanying muscle-sensations. We have seen that in this way the different ideational compounds, the complex feelings, the emotions, and the volitional processes are all resultants of the psychical processes of combination. Now, how are these combinations constituted, and what laws are they subject to? Psychologists generally have called them "Associations," since the English philosophy of the eighteenth century turned its attention to the importance of this process of combination. The opinion has often been expressed that this one concept is sufficient to include under it all psychical processes of combination. We shall soon see, however, that thereby a very important and characteristic difference is left out of account. We shall choose this difference, since it certainly influences all processes of consciousness, as our chief principle in a division of these combinations. This distinctive characteristic consists in the fact that one set of psychical combinations acts of its own accord, i.e. without the accompaniment of those feelings of activity which we learnt were constituent parts of the processes of apperception and volition; whereas another set is closely connected with these activities. At the same time, further distinctive characteristics in the combination processes run parallel to this one. Let us therefore call only those generally passive combination processes associations, and the active ones apperceptive combinations, or for shortness apperceptions. If we limit in this way the concept "association" in contra-distinction to the ordinary use of the term, still we must enlarge it considerably on the other side, if we wish to do justice to all the combinations of this sort that really exist. The old theory of association was founded exclusively on the observation of the memory-processes. With such a process we are accustomed to take note, first of all, merely of the ideational compounds of consciousness, and secondly, the ideas in such a schematic memory-process are arranged regularly in a temporal succession; for example, an outward impression acts first of all upon consciousness, and then we remember something previous that was similar to this impression, or stood in relation to it. Now these memory-processes, as a closer inspection will show, make up a remarkably small part of our associations. They are in fact of much less importance than many other forms. As soon as we compare this form with other forms, we recognise at once that it is merely a secondary form.
If we wish to arrange associations according to their simplicity and the closeness of their combinations, we can start with the following simple experiment. If we make the string of a piano sound by plucking it in the middle, then, as the science of physics teaches us, not only does the whole string vibrate, but each half vibrates as well in a smaller degree, and in general each third part, each fourth, &c., in ever decreasing amplitudes. These segments, which decrease in length according to the numerical series 1, 2, 3, &c., correspond to tones of increasing pitch—the half string corresponds to the octave, the third part to the fifth of the octave, the fourth to the double octave, and so on. If these high tones are then produced alone, one after another, by making the corresponding part of the string vibrate each time, and if we then return to the tone of the whole string, we can then, if we listen attentively, hear clearly, along with the stronger sounding fundamental tone, these overtones, or at least those nearest to the fundamental. We therefore say that the clang of a string, or of any other musical source, does not only consist of the one tone according to which we determine its pitch, but also of a series of overtones, which give it its timbre or clang-colour. This expression itself points to the fact that in hearing a clang there takes place psychologically an association, which is of a specially intimate kind. The above-described experiment of comparing a clang with some of its overtones teaches us that these latter really exist in sensation, and that we can perceive them with very intense attention. Nevertheless under ordinary circumstances we do not perceive them as independent tones, but they appear to us massed together only as a specific modification of the fundamental tone, and we call this its clang-colour or timbre. An association of this kind, in which the sensation-components are so fused into the resulting product that they can no longer be clearly perceived as isolated component parts, is called a fusion. Such a fusion can be either a very close one or a very loose one. A single clang is for example a close fusion, a chord is a loose one. The separate fundamental tones of a chord are bound fairly closely into one whole, but we can hear at least some of them quite plainly.
Similar fusions occur in the various senses, and they become very complicated owing to the fact that sensation-elements of several senses are joined together at the same time. The disappearance of the components into one resulting product brings it about that we cannot directly perceive the separate elements that make up this product by means of direct sensation, as is in part possible in the case of clang-fusions. We are forced to make use of an indirect method. We proceed from the principle, that each sensation, a change in which is of essential influence on the resulting idea, belongs to the components of this idea. A pronounced case of this kind is seen very clearly in spatial ideas of the senses of touch and sight. If any part of the skin is touched with a little rod, we can, as is well known, with a fair degree of certainty apprehend the place touched, without looking at it. Now in the pathological cases of partial paralysis, it is shown that there are two kinds of sensations that are of essential influence on this localisation. Firstly, it is considerably disturbed by a partial suspension of the outer cutaneous sensitivity. In this case the patient often localises the impression on a place far removed from the place touched. Secondly, complete or partial paralysis of the muscles in the region of the place touched, e.g. the muscles of the arm and hand in the case of a touch sensation on the hand, causes just as much confusion in localisation. In this case as well the patient may localise the impression on an absolutely wrong part of the body. Therefore we must presuppose that neither cutaneous nor muscle sensations alone are the original cause of the idea of the place touched, but that both together by fusion give rise to this idea. After this has once happened, the quality of the touch sensation which is peculiar to each part of the skin and which varies with the place of the impression, can in itself bring about a localisation. That in general both components, i.e. cutaneous and movement sensations, must fuse together in order to produce an idea of a certain place or locality, is clearly shown in blind people, and especially in those born blind. In their case the sense of sight, which determines the whole perception of space for those who can see, is wanting, and we observe in them a continuous and very lively co-operation of cutaneous sensations and movements of touch.
Exactly corresponding to these relations in the sense of touch are the phenomena that we observe in the formation of visual spatial ideas. Here as well we notice two sensation-components regularly working together. The one consists of the sensations of the retina. Analogous to the touch sensations of the skin, they vary in quality not only according to the constitution of the outer impressions, but also according to the part of the retina which is affected by the impression. The other component consists of the extremely delicate sensations which accompany the positions and movements of the eye. They vary in their intensity according to the length of the distance through which the movement travels, just like the sensations of movement of the other muscles of the body. We notice, therefore, that changes in the position of the retinal elements, which may occur in inflammations of the inside of the eye, or abnormalities in the mechanism of the eye-movements may disturb considerably our spatial perception. They cause sometimes apparent dislocations in the objects seen, and at other times illusions as to their size and distance. These influences can be demonstrated on the normal eye by means of experiments. By making the movement of the eye more difficult, we cause the length of a distance to be over-valued. If we compare two straight lines of exactly the same length, one of which is interrupted by a number of transverse lines, so that a continuous movement of the eye is hindered, then this divided line appears longer than the undivided one. We can also by systematic experiments change the normal relation between eye-movements and retinal sensations. It will then be observed that our vision slowly begins to adapt itself to this new relation between the eye-movements and the position of the retinal elements. This can be done by wearing spectacles with prismatic glasses for a considerable length of time. At first all objects appear distorted. A straight line appears curved, a circle looks like an oval, and so on. If the spectacles are worn for several days, these distortions disappear. It may happen that distortions again appear when the glasses are discarded. This phenomenon can scarcely be accounted for except in the following manner. The retinal sensations by means of local differences in quality, which we may call qualitative local signs, correspond to definite sensations of movement graduated as to intensity, which we may call intensive local signs. Their relation to the centre of the retina probably determines this correspondence. Now our experiment with the prismatic glasses shows that this relation is neither an absolutely permanent nor an innate one, but that it is acquired by practice. It is acquired by the function itself, and therefore, when the functional relations are changed, gives way to a different relation or correspondence. This combination possesses distinctly the character of an association, and in so far as in it the sensation-components only appear as modified elements of the resulting spatial idea, it also possesses the characteristics of a fusion. In contradistinction, however, to the intensive fusions of clangs and chords, this possesses the special characteristic, that it consists of elements out of different senses. For the qualitative local signs belong to the sense of sight or to the sense of touch if we are dealing with spatial cutaneous perceptions which are exactly analogous to visual perceptions; whereas the intensive local signs belong to sensations of movement or muscle sensations. Both together form a complex system of local signs.
Just as sensations fuse together into more or less complex ideas, so also do feelings fuse together into complex compounds, in which single elements appear to bear the rest, which act in a modifying manner upon the form, something analogous to the overtones of a clang. These affective fusions are again bound up most closely with the ideational fusions that correspond to them. The impression of a musical chord is composed of both. Only in a psychological analysis can we separate the ideational from the affective associations, which are the essential causes of the æsthetic character of the chord. One of the most important and simplest affective fusions of this kind is that of the so-called "common or organic feeling." It consists of an indefinite number of organic feelings, to which more or less lively feelings are joined, which in this case pre-eminently belong to the class of pleasant-unpleasant feelings. In this case, just as in the case of a chord, certain elements are predominant, while the others are merely modifying concomitants. Our general state of health, e.g. freshness and activeness or general displeasure and exhaustion, is essentially a product of this affective complex, in which under normal conditions the sensuous feelings joined to the strain and movement sensations of the muscles play the most important part.
A most important form of fusion consists of the impressions of our sense of hearing and of our organs of locomotion. These impressions are the intermediaries of our ideas of time. If we divide up into their elements the processes of consciousness caused by metronome beats of a medium rapidity, we find two classes—those that belong to the class of sensations and those that belong to feelings. As sensations we have first of all the single metronome beats divided from each other by empty intervals. These are not the only sensations. As we have shown above, there is also a weak sensation of strain which probably arises from the tensor muscle of the tympanum, and which lasts continuously from one beat to the other. To this is joined a further sensation in the mimic muscles surrounding the ear. The whole process, therefore, looked at from the point of view of sensation, appears as a continuous sensation-process, which is interrupted at regular intervals by stronger impulses arising from the objective impressions of the beats. To all this, however, as we saw before, there is added the regularly alternating feelings of strain and relaxation, which determine the rhythmical ideas. All these elements of sensation and feeling form in reality an indivisible whole. If a temporal idea is to arise, none of these components may be wanting, if the sensations are wanting, the feelings have, so to speak, no foundation. They can only arise if sensation impressions are present, upon which the feelings of expectation and realisation can be founded. On the other land the sensations remain unconnected, they lack a combination into a successive row, if the feelings of strain and relaxation are not present, for they directly help in the apprehension of the equality or inequality of the successive periods of time. If the beats are allowed to follow each other so slowly that the last one disappears out of the scope of consciousness when the new one enters, then the idea of time becomes absolutely uncertain. The same thing happens if, on the other hand, the time is so rapid that feelings of strain and relaxation cannot arise. In both cases it is obvious that any uncertain idea of time is only possible by reason of other extraneous factors. Just as all our objective measures of time, from the course of the sun to the vibrations of a tuning-fork used to measure time, depend upon regular periodic movements, so also is our subjective time-consciousness absolutely dependent upon rhythmical ideas. These arise first of all from our movements of locomotion, and then in a much richer and finer form are transmitted to us by our sense of hearing. In all these cases, however, the resulting idea of time can be divided up into a substratum of sensation and into an affective process of strain and relaxation, of expectation and realisation. In the idea of time they fuse perfectly together, so that the influence of these factors can only be shown by the essential changes, which the resulting idea undergoes, if one of these sensation or affective factors is altered in some marked degree.
Just as elements of consciousness are joined together by fusion into compounds, so these compounds themselves undergo manifold changes, out of which new combinations arise. Of great importance among these associations of the second class are those which we shall call assimilations and dissimilations. As ideational combinations they can be easily demonstrated, whereas the corresponding affective associations are joined to them rather as secondary components or form a special class of complex feelings, which are connected with the processes of recollection, recognition, memory, &c., and which we shall treat of in detail later on.
Let us first of all glance at some of the most important phenomena in connection with assimilation and dissimilation. To begin with the simplest case, we let one object of sight work in an assimilating manner upon another. We can achieve this most readily if we first of all make the difference between the two objects very small, and if secondly we bring them into a familiar relationship to each other, and so promote the idea of their identity. For example, we draw from one and the same centre sectors of a circle, and make one less than the others only by a few degrees. In spite of this we are inclined to apprehend all the sectors as equal. The larger ones work assimilatively upon the smaller one. To cause the opposite process of dissimilation, we draw one large sector among several smaller sectors. This appears, in contrast to the surrounding smaller sectors, very much enlarged, and we can convince ourselves of this by drawing on another piece of paper a sector of the same size as the one changed by dissimilation. This independent sector will then appear smaller than the one of its own size that is lying among the smaller sectors. This dissimilative change is generally called a contrast. We must not, however, confuse this dissimilative contrast with the contrast of feelings, where it is not a case of the formation of apparent differences in size, but of qualitative contrasts, such as pleasure and displeasure, or the increase of these.