Movement is another thing difficult to represent or imagine. You can determine for yourself immediately whether you can imagine even a slightly complicated movement. I can imagine one individual condition of a movement after another, sequentially, but I can not imagine the sequence. As Herbart says somewhere, a successive series of images is not a represented succession. But if we can not imagine this latter, what do we imagine is not what it ought to be. According to Stricker,[202] the representation of movement is a quale which can not be given in terms of any other sensory quality, and no movement can be remembered without the brain’s awakening a muscle-movement. Experience verifies this theory. The awakening of the muscular sense is frequently obvious whenever movement is thought of, and we may then perceive how, in the explanation or description of a movement, the innervation which follows the image in question, occurs. This innervation is always true. It agrees at least with what the witness has himself perceived and now tries to renew in his story. When we have him explain, for example, how some man had been choked, we may see movements of his hands which, however slight and obscure, still definitely indicate that he is trying to remember what he has seen, and this irrelevantly of what he is saying. This makes it possible to observe the alterations of images in the individual in question, an alteration which always occurs when the images are related to movements.
It follows further from the fact that movements are difficult to represent that the witness ought not to be expected accurately to recall them. Stricker says that for a long time he could not image a snow-fall, and succeeded only in representing one single instant of it. Now what is not capable of representation, can not well be recalled, and so we discover that it merely causes trouble to ask the witness to describe point by point even a simple sequence. The witness has only successive images, and even if the particular images are correct, he has nothing objective for the succession itself, nothing rooted in the sequence. He is helped, merely, by the logic of events and his memory—if these are scanty, the succession of images is scanty, and therefore the reproduction of the event is inadequate. Hence this scantiness is as little remarkable as the variety of description in various witnesses, a variety due to the fact that the sequentialization is subjective.
Drawing is a confirmation of the fact that we represent only a single instant of motion, for a picture can never give us a movement, but only a single state within that movement. At the same time we are content with what the picture renders, even when our image contains only this simple moment of movement. “What is seen or heard, is immediately, in all its definiteness, content of consciousness” (Schuppe)—but its movement is not.
The influence of time upon images is hardly indifferent. We have to distinguish the time necessary for the construction of an image, and the time during which an image lasts with uniform vividness. Maudsley believes the first question difficult to answer. He leans on Darwin, who points out that musicians play as quickly as they can apprehend the notes. The question will affect the lawyer in so far as it is necessary to determine whether, after some time, an image of an event may ensue from which it is possible to infer back to the individuality of the witness. No other example can be used here, because on the rocky problem of the occurrence of images are shattered even the regulative arts of most modern psychophysics.
The second problem is of greater significance. Whether any practical use of its solution can be made, I can not say, but it urges consideration. Exner has observed that the uniform vividness of an image lasts hardly a second. The image as a whole does not disappear in this time, but its content endures unchanged for so long at most. Then it fades in waves. The correctness of this description may be tested by anybody. But I should like to add that my observations of my own images indicate that in the course of a progressive repetition of the recall of an image its content is not equally capable of reproduction. I believe, further, that no essential leaps occur in this alteration of the content of an idea, but that the alteration moves in some definite direction. If, then, I recall the idea of some object successively, I will imagine it not at one time bigger, then smaller, then again bigger, etc.; on the contrary, the series of images will be such that each new image will be either progressively bigger or progressively smaller.
If this observation of mine is correct and the phenomenon is not purely personal, Exner’s description becomes of great value in examination, which because of its length, requires the repeated recall of standardizing images, and this in its turn causes an alteration in the ideational content. We frequently observe that a witness persuades himself into the belief of some definite idea in the course of his examination, inasmuch as with regard to some matter he says more and more definite things at the end than at the beginning. This may possibly be contingent on the alteration of frequently recalled ideas. One could make use of the process which is involved in the reproduction of the idea, by implying it, and so not being compelled to return endlessly to something already explained.
How other people construct their ideas, we do not, as we have seen, know, and the difficulty of apprehending the ideas or images of other people, many authorities clearly indicate.[203]
Topic 4. INTELLECTUAL PROCESSES.
Section 46. (a) General Considerations.
Lichtenberg said somewhere, “I used to know people of great scholarship, in whose head the most important propositions were folded up in excellent order. But I don’t know what occurred there, whether the ideas were all mannikins or all little women—there were no results. In one corner of the head, these gentlemen put away saltpeter, in another sulphur, in a third charcoal, but these did not combine into gunpowder. Then again, there are people in whose heads everything seeks out and finds everything else, everything pairs off with everything else, and arranges itself variously.” What Lichtenberg is trying to do is to indicate that the cause of the happy condition of the last-named friends is imagination. That imagination is influential, is certain, but it is equally certain that the human understanding is so different with different people as to permit such phenomena as Lichtenberg describes. I do not want to discuss the quantity of understanding. I shall deal, this time, with its quality, by means of which the variety of its uses may be explained. It would be a mistake to think of the understanding as capable of assuming different forms. If it were it would be possible to construct from the concept understanding a group of different powers whose common quality would come to us off-hand. But with regard to understanding we may speak only of more or less and we must think of the difference in effect in terms only of the difference of the forms of its application. We see the effects of the understanding alone, not the understanding itself, and however various a burning city, cast iron, a burn, and steaming water may be, we recognize that in spite of the difference of effect, the same fire has brought about all these results. The difference in the uses of the understanding, therefore, lies in the manner of its application. Hence these applications will help us, when we know them, to judge the value of what they offer us. The first question that arises when we are dealing with an important witness who has made observations and inferences, is this: “How intelligent is he? and what use does he make of his intelligence? That is, What are his processes of reasoning?”