§ [15]. Ideation
The same laws which govern the supplementing of impressions by images, govern also the supplementing of images by other images. We refer to the appearance of images supplementing other images by the word remembering, or ideation.
What we remember is always deficient in details compared with what we perceive. Remember a landscape, a street scene, a well-known person. Innumerable details are always lacking in the idea, although they were present in the corresponding percept. These details which are lacking may be either parts separable from the object, or mere attributes of sensation inseparable from the sensation. On the other hand, ideas are richer than percepts. They contain elements obtained from other similar perceptions and added by association, as when the idea of a landscape is enriched by a tower, the idea of a person by a beard, which actually are not present at these places.
Ideas are also strongly influenced and altered by other ideas which happen to be in consciousness at the same time (“set of the mind”); for instance by questions, particularly by questions in the negative form—“did you not,” “was this not,”—by the wish to make a good impression upon others, and by similar factors. We may have no intention of exaggerating, in Falstaff’s fashion, the significance of our deeds; nevertheless our memories become gradually modified so that the uncommon, the important, the valuable in them is emphasized, and the common, the insignificant, the unpleasant is obliterated. Wherever our memories are fragmentary and indefinite, they offer but slight resistance to questions attacking this point, for instance: Do you believe that the gentleman was as tall as you are?
Memories are thus, not exceptionally, but universally inaccurate representations of that which has been perceived. This has recently been proved by direct experimental tests. Since percepts, although they rest on a foundation of external stimulation, are so strongly influenced by the mind’s own manner of functioning, the existence of this influence in the case of imagery, lacking such a foundation, is not surprising. Although memories are but rarely totally misleading, mankind has long ago learned to rely upon memory in all important business and legal transactions only when there is agreement between the memories of several witnesses. The changeableness of memory is particularly strong in the child’s mind. The perceptual experiences have not been so often repeated as in the adult mind, and the practical importance of accuracy of remembering has not made itself so much felt. For both reasons the child’s memory is very unreliable.
The word imagination is frequently used to signify a specially strong ability to modify memories by associated images. Thus we speak of the imagination of the child—but also of the artist and the scientist. Without imagination the scientist would not succeed in his task of making the phenomena of nature more comprehensible by showing the consequences of the remotest relations between things. It is clear, however, that imagination is not a fundamental “faculty” of the mind, separable from other “faculties,” but a result of the fundamental laws governing mental functions.
Let us turn to the fragmentary nature of reproduced experience and discuss its significance. That previous experience can be reproduced only in fragments is the direct result of the selective power of attention, which asserts itself in both perception and ideation. Not every quality of a thing presented is equally interesting. A child having a watch takes interest mainly in the ticking and in the glitter of the golden case. Meeting a dog, he gives attention to the terrifying bark and the multiplicity of legs. Suppose now that the dog regularly occurred together with a special impression, perhaps a spoken word; then the recurring of this symbol will tend to reproduce in the child’s mind the image of the dog. But the pressure of many competing tendencies does not permit the reproduction of all the qualities of the dog which have become conscious on former meetings with this animal. Only an extract, so to speak, of these qualities is reproduced, and this is made up of those which were formerly especially interesting,—the bark and the legs.
Another factor determining the selection of special qualities of a thing for reproduction is the frequency with which each quality reappears in things which are different in certain respects, but in other respects belong to the same class. The trees of a forest beside which I am walking have many individual differences. But certain features are common to all the trees. These common features reappear again and again, while each of the other features appears only now and then. The same can be said of various dogs met on the street, of various tones of a violin, and so on. If the perception of the trees is experienced together with a certain other percept which may serve as a symbol for the trees, for example the word tree, the association of the symbol with those regularly repeated qualities becomes firmly established, whereas the association with the other, more or less varying qualities, remains comparatively feeble. The result is that the symbol tends to reproduce almost exclusively the former qualities. These come to make up a separate group of images, a general idea.
The laws of attention, practice, and memory, together with the simple uniformity of nature just mentioned, produce thus a peculiar result. They remove ideation from the accidents of external events in an incomparably higher degree than perception. They bring about ideas of the separate qualities of the things perceived, abstractions, and ideas of common features, general ideas. In many cases an idea is both an abstraction and a general idea. Examples of such ideas to which no equally simple concrete object corresponds, are the idea of a mere length, the color red, sight, a dog in general, a tree in general.