Criminal Psychology - Hans Gross (list of e readers .TXT) 📗

is lacking in the ordinary function of seeing; nevertheless it is permissible to conceive the psychical function of ordinary perception as unconscious inferences, inasmuch as this name will completely distinguish them from the commonly so-called conscious inferences.

 

The last-named condition is of especial importance to us. We need investigation to determine the laws of the influence of optical and acoustical knowledge upon perception. That these laws are influential may be verified easily. Whoever is ignorant, e. g., that a noise is reflected back considerably, will say that a wagon is turning from the side from which the noise comes, though if he knows the law, if he knows that fact, his answer would be reversed. So, as every child knows that the reflection of sound is frequently deceptive, everybody who is asked in court will say that he believes the wagon <p 190>

to be on the right side though it might as well have been on the left. Again, if we were unaware that light is otherwise refracted in water than in air we could say that a stick in the water has been bent obtusely, but inasmuch as everybody knows this fact of the relation of light to water, he will declare that the stick appears bent but really is straight.

 

From these simplest of sense-perceptions to the most complicated, known only to half a dozen foremost physicists, there is an infinite series of laws controlling each stage of perception, and for each stage there is a group of men who know just so much and no more. We have, therefore, to assume that their perceptions will vary with the number and manner of their accomplishments, and we may almost convince ourselves that each examinee who has to give evidence concerning his sense-perception should literally undergo examination to make clear his scholarly status and thereby the value of his testimony. Of course, in practice this is not required.

First of all we judge approximately a man’s nature and nurture and according to the impression he makes upon us, thence, his intellectual status. This causes great mistakes. But, on the other hand, the testimony is concerned almost always with one or several physical events, so that a simple relational interrogation will establish certainly whether the witness knows and attends to the physical law in question or not. But anyway, too little is done to determine the means a man uses to reach a certain perception. If instantaneous contradictions appear, there is little damage, for in the absence of anything certain, further inferences are fortunately made in rare cases only. But when the observation is that of one person alone, or even when more testify but have accidentally the same amount of knowledge and hence have made the same mistake, and no contradiction appears, we suppose ourselves to possess the precise truth, confirmed by several witnesses, and we argue merrily on the basis of it. In the meantime we quite forget that contradictions are our salvation from the trusting acceptance of untruth—

and that the absence of contradiction means, as a rule, the absence of a starting point for further examination.

 

For this reason and others modern psychology requires us to be cautious. Among the others is the circumstance that perceptions are rarely pure. Their purity consists in containing nothing else than perception; they are mixed when they are connected with imaginations, judgments, efforts, and volitions. How rarely a perception is pure I have already tried to show; judgments almost <p 191>

always accompany it. I repeat too, that owing to this circumstance and our ignorance of it, countless testimonies are interpreted altogether falsely. This is true in many other fields. When, for example, A. Fick says: “The condition we call sensation occurs in the consciousness of the subject when his sensory nerves are stimulated,”

he does not mean that the nervous stimulus in itself is capable of causing the condition in question. This one stimulus is only a single tone in the murmur of countless stimuli, which earlier and at the same time have influenced us and are different in their effect on each man. Therefore, that single additional tone will also be different in each man. Or, when Bernstein says that “Sensation, i. e., the stimulation of the sensorium and the passage of this stimulation to the brain, does not in itself imply the perception of an object or an event in the external world,” we gather that the objectivity of the perception works correctively not more than one time out of many. So here again everything depends upon the nature and nurture of the subject.

 

Sensations are, according to Aubert, still more subjective. “They are the specific activity of the sense organs, (not, therefore, passive as according to Helmholtz, but active functions of the sense organs).

Perception arises when we combine our particular sensations with the pure images of the spirit or the schemata of the understanding, especially with the pure image of space. The so-called ejection or externalization of sensations occurs only as their scheme and relation to the unity of their object.”

 

So long as anything is conceived as passive it may always recur more identically than when it is conceived as active. In the latter case the individuality of the particular person makes the perception in a still greater degree individual, and makes it almost the creature of him who perceives. Whether Aubert is right or not is not our task to discover, but if he is right then sense-perception is as various as is humanity. The variety is still further increased by means of the comprehensive activity which Fischer[1] presupposes. “Visual perception has a comprehensive or compounding activity. We never see any absolute simple and hence do not perceive the elements of things. We see merely a spatial continuum, and that is possible only through comprehensive activity—especially in the case of movement in which the object of movement and the environment must both be perceived.” But each individual method of “comprehension” is different. And it is uncertain whether this <p 192>

is purely physical, whether only the memory assists (so that the attention in biased by what has been last perceived), whether imagination is at work or an especial psychical activity must be presupposed in compounding the larger elements. The fact is that men may perceived an enormous variety of things with a single glance.

And generally the perceptive power will vary with the skill of the individual. The narrowest, smallest, most particularizing glance is that of the most foolish; and the broadest, most comprehensive, and comparing glance, that of the most wise. This is particularly noticeable when the time of observation is short. The one has perceived little and generally the least important; the other has in the same time seen everything from top to bottom and has distinguished between the important and the unimportant, has observed the former rather longer than the latter, and is able to give a better description of what he has seen. And then, when two so different descriptions come before us, we wonder at them and say that one of them is untrue.[1b]

 

[1] E. L. Fischer: Theorie der Gesichtswahrnehmung. Mainz 1891.

 

[1b] Cf. Archiv, XVI, 371.

 

The speed of apperception has been subjected to measurement by Auerbach, Kries, Baxt, von Tigerstedt and Bergqvist, Stern, Vaschide, Vurpass, etc. The results show 0.015 to 0.035 seconds for compounded images. Unfortunately, most of these experiments have brought little unanimity in the results and have not compared, e. g., the apperception-times of very clever people with those of very slow and stupid ones. In the variety of perception lies the power of presentation (in our sense of the term). In the main other forces assist in this, but when we consider how the senses work in combination we must conclude that they determine their own forms. “If we are to say that sense experience instructs us concerning the manifoldness of objects we may do so correctly if we add the scholium that many things could not be mentioned without synthesis.”

So D<o:>rner writes. But if we approach the matter from another side, we see how remarkable it is that human perceptions can be compared at all. Hermann Schwarz says “According to the opinion of the physicists we know external events directly by means of the organs, the nerves of which serve passively to support consciousness in the perception of such events. On the contrary, according to the opinion of most physiologists, the nerve fibers are active in the apprehension of external events, they modify it, alter it until it is well nigh unrecognizable, and turn it over to consciousness only after the original process has undergone still another trans-

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formation into new forms of mechanical energy in the ganglion cells of the outer brain. This is the difference between the physical theory of perception and the physiological.”

 

In this connection there are several more conditions pertaining to general sense-perception. First of all there is that so-called vicariousness of the senses which substitutes one sense for another, in representation. The *actual substitution of one sense by another as that of touch and sight, does not belong to the present discussion.

The substitution of sound and sight is only apparent. E. g., when I have several times heard the half-noticed voice of some person without seeing him, I will imagine a definite face and appearance which *are pure imagination. So again, if I hear cries for help near some stream, I see more or less clearly the form of a drowning person, etc. It is quite different in touching and seeing; if I touch a ball, a die, a cat, a cloth, etc., with my eyes closed, then I may so clearly see the color of the object before me that I might be really seeing it. But in this case there is a real substitution of greater or lesser degree.

 

The same vicariousness occurs when perception is attributed to one sense while it properly belongs to another. This happens particularly at such times when one has not been present during the event or when the perception was made while only half awake, or a long time ago, and finally, when a group of other impressions have accompanied the event, so that there was not time enough, if I may say so, properly to register the sense impression. So, e. g., some person, especially a close friend, may have been merely heard and later quite convincingly supposed to have been seen. Sensitive people, who generally have an acuter olfactory sense than others, attach to any perceived odor all the other appropriate phenomena.

The vicariousnesses of visual sensations are the most numerous and the most important. Anybody who has been pushed or beaten, and has felt the blows, will, if other circumstances permit and the impulse is strong enough, be convinced that he has seen his assaulter and the manner of the assault. Sometimes people who are shot at will claim to have seen the flight of the ball. And so again they will have seen in a dark night a comparatively distant wagon, although they have only heard the noise it made and felt the vibration. It is fortunate that, as a rule, such people try to be just in answering to questions which concern this substitution of one sense-perception for another. And such questions ought to be urgently put. That a false testimony can cause significant errors is as obvious as the fact <p 194>

that such substitutions are most frequent with nervous and imaginative persons.

 

Still more significant is that characteristic phenomenon, to us of considerable importance, which might be called retrospective illumination of perception. It consists in the appearance of a sense-perception under conditions of some noticeable interruption, when the stimulus does not, as a rule, give rise to that perception. I cite a simple example in which I first observed