Part II. OBJECTIVE CONDITIONS OF CRIMINAL INVESTIGATION: THE MENTAL ACTIVITY OF THE EXAMINEE.

Title A. General Conditions.

Topic I. OF SENSE-PERCEPTION.

Section 35.

Our conclusions depend upon perceptions made by ourselves and others. And if the perceptions are good our judgments may be good, if they are bad our judgments must be bad. Hence, to study the forms of sense-perception is to study the fundamental conditions of the administration of law, and the greater the attention thereto, the more certain is the administration.

It is not our intention to develop a theory of perception. We have only to extract those conditions which concern important circumstances, criminologically considered, and from which we may see how we and those we examine, perceive matters. A thorough and comprehensive study of this question can not be too much recommended. Recent science has made much progress in this direction, and has discovered much of great importance for us. To ignore this is to confine oneself merely to the superficial and external, and hence to the inconceivable and incomprehensible, to ignoring valuable material for superficial reasons, and what is worse, to identifying material as important which properly understood has no value whatever.

Section 36. (a) General Considerations.

The criminalist studies the physiological psychology[172] of the senses and their functions, in order to ascertain their nature, their influence upon images and concepts, their trustworthiness, their reliability and its conditions, and the relation of perception to the object. The question applies equally to the judge, the jury, the witness, and the accused. Once the essence of the function and relation of sense-perception is understood, its application in individual cases becomes easy.

The importance of sense-perception need not be demonstrated. “If we ask,” says Mittermaier, “for the reason of our conviction of the truth of facts even in very important matters, and the basis of every judgment concerning existence of facts, we find that the evidence of the senses is final and seems, therefore, the only true source of certainty.”

There has always, of course, been a quarrel as to the objectivity and reliability of sense-perception. That the senses do not lie, “not because they are always correct, but because they do not judge,” is a frequently quoted sentence of Kant’s; the Cyrenaics have already suggested this in asserting that pleasure and pain alone are indubitable. Aristotle narrows the veracity of sensation to its essential content, as does Epicurus. Descartes, Locke and Leibnitz have suggested that no image may be called, as mere change of feeling, true or false. Sensationalism in the work of Gassendi, Condillac, and Helvetius undertook for this reason the defense of the senses against the reproach of deceit, and as a rule did it by invoking the infallibility of the sense of touch against the reproach of the contradictions in the other senses. Reid went back to Aristotle in distinguishing specific objects for each sense and in assuming the truth of each sense within its own field.

That these various theories can be adjusted is doubtful, even if, from a more conservative point of view, the subject may be treated quantitatively. The modern quantification of psychology was begun by Herbart, who developed a mathematical system of psychology by introducing certain completely unempirical postulates concerning the nature of representation and by applying certain simple premises in all deductions concerning numerical extent. Then came Fechner, who assumed the summation of stimuli. And finally these views were determined and fixed by the much-discussed Weber’s Law, according to which the intensity of the stimulus must increase in the proportion that the intensity of the sensation is to increase; i.e., if a stimulus of 20 units requires the addition of 3 before it can be perceived, a stimulus of 60 units would require the addition of 9. This law, which is of immense importance to criminalists who are discussing the sense-perceptions of witnesses, has been thoroughly and conclusively dealt with by A. Meinong.[173]

“Modern psychology takes qualities perceived externally to be in themselves subjective but capable of receiving objectivity through our relation to the outer world.... The qualitative character of our sensory content produced by external stimuli depends primarily on the organization of our senses. This is the fundamental law of perception, of modern psychology, variously expressed, but axiomatic in all physiological psychology.”[174] In this direction Helmholtz[175] has done pioneer work. He treats particularly the problem of optics, and physiological optics is the study of perception by means of the sense of sight. We see things in the external world through the medium of light which they direct upon our eyes. The light strikes the retina, and causes a sensation. The sensation brought to the brain by means of the optic nerve becomes the condition of the representation in consciousness of certain objects distributed in space.... We make use of the sensation which the light stimulates in the mechanism of the optic nerve to construct representations concerning the existence, form, and condition of external objects. Hence we call images perceptions of sight. (Our sense-perception, according to this theory, consists, therefore, entirely of sensations; the latter constitute the stuff or the content from which the other is constructed). Our sensations are effects caused in our organs, externally, and the manifestation of such an effect depends essentially upon the nature of the apparatus which has been stimulated.

There are certain really known inferences, e.g., those made by the astronomer from the perspective pictures of the stars to their positions in space. These inferences are founded upon well-studied knowledge of the principles of optics. Such knowledge of optics 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 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 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[176] 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 is purely physical, whether only the memory assists (so that the attention is 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 perceive 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.[177]

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 Dörner 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 transformation 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 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 this fact. Since I was a child there had been in my bed-room a clock, the loud ticking of which habit of many years prevented my hearing. Once, as I lay awake in bed, I heard it tick suddenly three times, then fall silent and stop. The occurrence interested me, I quickly got a light and examined the clock closely. The pendulum still swung, but without a sound; the time was right. I inferred that the clock must have stopped going just a few minutes before. And I soon found out why: the clock is not encased and the weight of the pendulum hangs free. Now under the clock there always stood a chair which this time had been so placed as to be inclined further backward. The weight followed that inclination and so the silence came about.

I immediately made an experiment. I set the clock going again, and again held the weight back. The last beats of the pendulum were neither quicker nor slower, nor louder or softer than any others, before the sudden stoppage of the clock. I believe the explanation to be as follows: As customary noises especially are unheard, I did not hear the pendulum of the clock. But its sudden stopping disturbed the balance of sound which had been dominating the room. This called attention to the cause of the disturbance, i.e., the ticking which had ceased, and hence perception was intensified backwards and I heard the last ticks, which I had not perceived before, one after another. The latent stimulus caused by the ticking worked backward. My attention was naturally awakened only after the last tick, but my perception was consecutive.

I soon heard of another case, this time, in court. There was a shooting in some house and an old peasant woman, who was busy sewing in the room, asserted that she had just before the shooting heard a few steps in the direction from which the shot must have come. Nobody would agree that there was any reason for supposing that the person in question should have made his final steps more noisily than his preceding ones. But I am convinced that the witness told the truth. The steps of the new arrival were perceived subconsciously; the further disturbance of the perception hindered her occupation and finally, when she was frightened by the shot, the upper levels of consciousness were illuminated and the noises which had already reached the subconsciousness passed over the threshold and were consciously perceived.

I learned from an especially significant case, how the same thing could happen with regard to vision. A child was run over and killed by a careless coachman. A pensioned officer saw this through the window. His description was quite characteristic. It was the anniversary of a certain battle. The old gentleman, who stood by the window thinking about it and about his long dead comrades, was looking blankly out into the street. The horrible cry of the unhappy child woke him up and he really began to see. Then he observed that he had in truth seen everything that had happened before the child was knocked over—i.e., for some reason the coachman had turned around, turning the horses in such a way at the same time that the latter jumped sidewise upon the frightened child, and hence the accident. The general expressed himself correctly in this fashion: “I saw it all, but I did not perceive and know that I saw it until after the scream of the child.” He offered also in proof of the correctness of his testimony, that he, an old cavalry officer, would have had to see the approaching misfortune if he had consciously seen the moving of the coachman, and then he would have had to be frightened. But he knew definitely that he was frightened only when the child cried out—he could not, therefore, have consciously perceived the preceding event. His story was confirmed by other witnesses.

This psychological process is of significance in criminal trials, inasmuch as many actionable cases depend upon sudden and unexpected events, where retrospective illumination may frequently come in. In such cases it is most important to determine what actually has been perceived, and it is never indifferent whether we take the testimony in question as true or not.

With regard to the senses of criminals, Lombroso and Ottolenghi have asserted that they are duller than those of ordinary people. The assertion is based on a collection made by Lombroso of instances of the great indifference of criminals to pain. But he has overlooked the fact that the reason is quite another thing. Barbarous living and barbarous morals are especially dulling, so that indifference to pain is a characteristic of all barbarous nations and characters. Inasmuch as there are many criminals among barbarous people, barbarity, criminality and indifference to pain come together in a large number of cases. But there is nothing remarkable in this, and a direct relation between crime and dullness of the senses can not be demonstrated.

(b) The Sense of Sight.

Section 37. (1) General Considerations.

Just as the sense of sight is the most dignified of all our senses, it is also the most important in the criminal court, for most witnesses testify as to what they have seen. If we compare sight with the hearing, which is next in the order of importance, we discover the well-known fact that what is seen is much more certain and trustworthy than what is heard. “It is better to see once than to hear ten times,” says the universally-valid old maxim. No exposition, no description, no complication which the data of other senses offer, can present half as much as even a fleeting glance. Hence too, no sense can offer us such surprises as the sense of sight. If I imagine the thunder of Niagara, the voice of Lucca, the explosion of a thousand cartridges, etc., or anything else that I have not heard, my imagination is certainly incorrect, but it will differ from reality only in degree. It is quite different with visual imagination. We need not adduce examples of magnificence like the appearance of the pyramids, a tropical light; of a famous work of art, a storm at sea, etc. The most insignificant thing ever seen but variously pictured in imagination will be greeted at first sight with the words: “But I imagined it quite different!” Hence the tremendous importance of every local and material characteristic which the criminal court deals with. Every one of us knows how differently he has, as a rule, imagined the place of the crime to be; how difficult it is to arrive at an understanding with the witness concerning some unseen, local characteristic, and how many mistakes false images of the unseen have caused. Whenever I ciceroned anybody through the Graz Criminal Museum, I was continually assailed with “Does this or that look so? But I thought it looked quite different!” And the things which evoke these exclamations are such as the astonished visitors have spoken and written about hundreds of times and often passed judgments upon. The same situation occurs when witnesses narrate some observation. When the question involves the sense of hearing some misunderstanding may be popularly assumed. But the people know little of optical illusions and false visual perceptions, though they are aware that incorrect auditions are frequent matters of fact. Moreover, to the heard object a large number of more or less certain precautionary judgments are attached. If anybody, e.g., has heard a shot, stealthy footsteps, crackling flames, we take his experience always to be approximate. We do not do so when he assures us he has seen these things or their causes. Then we take them—barring certain mistakes in observation,—to be indubitable perceptions in which misunderstanding is impossible.

In this, again, is the basis for the distrust with which we meet testimony concerning hearsay. For we feel uncertain in the mere absence of the person whose conversation is reported, since his value can not be determined. But a part of the mistrust lies in the fact that it is not vision but the perennially half-doubted hearing that is in issue. Lies are assigned mainly to words; but there are lies which are visual (deceptions, maskings, illusions, etc.). Visual lies are, however, a diminishing minority in comparison with the lies that are heard.

The certainty of the correctness of vision lies in its being tested with the sense of touch,—i.e. in the adaptation of our bodily sense to otherwise existing things. As Helmholtz says, “The agreement between our visual perceptions and the external world, rests, at least in the most important matters, on the same ground that all our knowledge of the actual world rests on, upon the experience and the lasting test of their correctness by means of experiments, i.e., of the movements of our bodies.” This would almost make it seem that the supreme judge among the senses is the touch. But that is not intended; we know well enough to what illusions we are subject if we trust the sense of touch alone. At the same time we must suppose that the question here is one of the nature of the body, and this can be measured only by something similar, i.e., by our own physical characteristics, but always under the control of some other sense, especially the sense of sight.

The visual process itself consists, according to Fischer, “of a compounded series of results which succeed each other with extraordinary rapidity and are causally related. In this series the following elements may principally be distinguished.

(1) The physico-chemical process.

(2) The physiologico-sensory.

(3) The psychological.

(4) The physiologico-motor.

(5) The process of perception.”

It is not our task to examine the first four elements. In order clearly to understand the variety of perception, we have to deal with the last only. I once tried to explain this by means of the phenomenon of instantaneous photographs (cinematographs). If we examine one such representing an instant in some quick movement, we will assert that we never could have perceived it in the movement itself. This indicates that our vision is slower than that of the photographic apparatus, and hence, that we do not apprehend the smallest particular conditions, but that we each time unconsciously compound a group of the smallest conditions and construct in that way the so-called instantaneous impressions. If we are to compound a great series of instantaneous impressions in one galloping step, we must have condensed and compounded a number of them in order to get the image that we see with our eyes as instantaneous. We may therefore say that the least instantaneous image we ever see with our eyes contains many parts which only the photographic apparatus can grasp. Suppose we call these particular instances a, b, c, d, e, f, g, h, i, j, k, l, m; it is self-evident that the manner of their composition must vary with each individual. One man may compound his elements in groups of three: a, b, c,—d, e, f,—g, h, i, etc.; another may proceed in dyads: a, b,—c, d,—e, f,—g, h,—etc.; a third may have seen an unobservable instant later, but constructs his image like the first man: b, c, d,—l, m, n, etc.; a fourth works slowly and rather inaccurately, getting: a, c, d,—f, h, i,—etc. Such variations multiply, and when various observers of the same event describe it they do it according to their different characteristics. And the differences may be tremendous. Substitute numerals for letters and the thing becomes clear. The relative slowness of our apprehension of visual elements has the other consequence that we interpolate objects in the lacunæ of vision according to our expectations. The best example of this sort of thing would be the perception of assault and battery. When ten people in an inn see how A raises a beer glass against B’s head, five expect: “Now he’ll pound him,” and five others: “Now he’ll throw it.” If the glass has reached B’s head none of the ten observers have seen how it reached there, but the first five take their oath that A pounded B with the glass, and the other five that he threw it at B’s head. And all ten have really seen it, so firmly are they convinced of the correctness of their swift judgment of expectation. Now, before we treat the witness to some reproach like untruth, inattention, silliness, or something equally nice, we had better consider whether his story is not true, and whether the difficulty might not really lie in the imperfection of our own sensory processes. This involves partly what Liebmann has called “anthropocentric vision,” i.e., seeing with man as the center of things. Liebmann further asserts, “that we see things only in perspective sizes, i.e., only from an angle of vision varying with their approach, withdrawal and change of position, but in no sense as definite cubical, linear, or surface sizes. The apparent size of an object we call an angle of vision at a certain distance. But, what indeed is the different, true size? We know only relations of magnitude.” This description is important when we are dealing with testimony concerning size. It seems obvious that each witness who speaks of size is to be asked whence he had observed it, but at the same time a great many unexpected errors occur, especially when what is involved is the determination of the size of an object in the same plane. One need only to recall the meeting of railway tracks, streets, alleys, etc., and to remember how different in size, according to the point of view of the witness, various objects in such places must appear. Everybody knows that distant things seem smaller than near ones, but almost nobody knows what the difference amounts to. For examples see Lotze, “Medical Psychology,” Leipzig, 1852.

In addition we often think that the clearness of an object represents its distance and suppose that the first alone determines the latter. But the distinctness of objects, i.e., the perceptibility of a light-impression, depends also upon the absolute brightness and the differences in brightness. The latter is more important than is supposed. Try to determine how far away you can see a key-hole when the wall containing the door is in the shadow, and when there is a window opposite the key-hole. A dark object of the size of a key-hole will not be visible at one hundredth of the distance at which the key-hole is perceived. Moreover, the difference in intensity is not alone in consideration; the intensity of the object with regard to its background has yet to be considered. Aubert has shown that the accuracy of the distinction is the same when a square of white paper is looked at from an angle of 18´´, and when conversely a square of black paper on white background is looked at from an angle of 35´´. “When we put a gray paper in the sunshine, it may become objectively brighter than white paper in shadow. But this does not prevent us from knowing one as gray and the other as pure white. We separate the color of the object from the intensity of the incident light.” But this is not always so simple, inasmuch as we know in the case in hand which paper is gray and which white, which is in the sunlight and which in the shadow. But if these facts are not known mistakes often occur so that a man dressed in dark clothes but in full light will be described as wearing lighter clothes than one who wears light clothes in the shadow.

Differences of illumination reveal a number of phenomena difficult to explain. Fechner calls attention to the appearance of stars: “At night everybody sees the stars, in daylight not even Sirius or Jupiter is seen. Yet the absolute difference between those places in the heavens where the stars are and the environing places is just as great as in the night—there is only an increase in illumination.” Of still greater importance to us is the circumstance noted but not explained by Bernstein. If, in daylight, we look into a basement room from outside, we can perceive nothing, almost; everything is dark, even the windows appear black. But in the evening, if the room is ever so slightly illuminated, and we look into it from outside, we can see even small articles distinctly. Yet there was much intenser light in the room in question during the day than the single illumination of the night could have provided. Hence, it is asserted, the difference in this case is a standard one. In open day the eye is accustomed to the dominating brightness of daylight, beside which the subdued illumination of the room seems relatively dark. But in the evening one is in the dark, and hence even the little light of a single candle is enough to enable one to see. That this explanation is untrue is shown by the fact that the phenomenon is not regulated even when the circumstances in question are made identical. If, for example, you approach the window in daylight with your eyes shut, lean your forehead against the pane and shut out the light on the sides with your hands, and then open your eyes, you see as little in the room as when you looked into it without performing this ceremony. So again, if during the night you gazed at some near-by gas lamp and then glanced into the room, there is only a few moments’ indistinctness at most, after that the single candle is enough. The reason, then, must be different from the assigned one—but whatever it is, we need only to maintain that immediate judgment concerning numerous cases involving situations of this kind would be overhasty. It is often said that a witness was able to see this or that under such and such illumination, or that he was unable to see it, although he denies his ability or inability. The only solution of such contradictions is an experiment. The attempt must be made either by the judge or some reliable third person, to discover whether, under the same conditions of illumination, anything could be seen at the place in question or not.

As to what may be seen in the distance, experiment again, is the best judge. The human eye is so very different in each man that even the acute examination into what is known of the visual image of the Pleiades shows that the average visual capacity of classic periods is no different from our own, but still that there was great variety in visual capacity. What enormous visual power is attributed to half-civilized and barbarous peoples, especially Indians, Esquimos, etc.! Likewise among our own people there are hunters, mountain guides, etc., who can see so clearly in the distance that mere stories about it might be fables. In the Bosnian campaign of 1878 we had a soldier who in numerous cases of our great need to know the enemy’s position in the distance could distinguish it with greater accuracy than we with our good field-glasses. He was the son of a coal-miner in the Styrian mountains, and rather a fool. Incidentally it may be added that he had an incredible, almost animal power of orientation.

As we know little concerning far-sightedness, so also we are unable to define what near-sighted people can see. Inasmuch as their vision does not carry, they are compelled to make intellectual supplementations. They observe the form, action, and clothes of people more accurately than sharp-eyed persons, and hence recognize acquaintances at a greater distance than the latter. Therefore, before an assertion of a short-sighted man is doubted an experiment should be made, or at least another trustworthy short-sighted person should be asked for his opinion.

The background of objects, their movement and form have decided effects on the difference in visual perception. It is an ancient observation that lengthy objects like poles, wires, etc., are visible at incomparably greater distances than, e.g., squares of the same length. In examination it has been shown that the boundary of accurate perception can hardly be determined. I know a place where under favorable illumination taut, white and very thin telephone wires may be seen at a distance of more than a kilometer. And this demands a very small angle of vision.

Humboldt calls attention to the large number of “optical fables.” He assures us that it is certainly untrue that the stars may be seen in daylight from a deep well, from mines, or high mountains, although this has been repeatedly affirmed since Aristotle.

The explanation of our power to see very thin, long objects at a very great distance, is not our affair, but is of importance because it serves to explain a number of similar phenomena spoken of by witnesses. We have either incorrectly to deny things we do not understand, or we have to accept a good deal that is deniable. We will start, therefore, with the well-known fact that a point seen for a considerable time may easily disappear from perception. This has been studied by Helmholtz and others, and he has shown how difficult it is to keep a point within the field of vision for only ten or twenty minutes. Aubert examines older studies of the matter and concludes that this disappearance or confusion of an object is peripheral, but that fixation of a small object is always difficult. If we fix a distant point it is disappearing at every instant so that an accurate perception is not possible; if however we fix upon a long, thin body, e.g., a wire, it is unnecessary to fix a single point and we may see the object with a wandering eye, hence more clearly.

Helmholtz adds that weakly objective images disappear like a wet spot on warm tin, at the moment a single point is fixed, as does e.g., a landscape seen at night. This last acute observation is the basis of many a testimony concerning the sudden disappearance of an object at night. It has helped me in many an examination, and always to advantage.

In this connection the over-estimation of the moon’s illuminating power is not to be forgotten. According to Helmholtz the power of the full moon is not more than that of a candle twelve feet away. And how much people claim to have seen by moonlight! Dr. Vincent[178] says that a man may be recognized during the first quarter at from two to six meters, at full moon at from seven to ten meters, and at the brightest full moon, an intimate may be recognized at from fifteen to sixteen meters. This is approximately correct and indicates how much moonlight is over-estimated.

In addition to the natural differences of sight there are also those artificially created. How much we may help ourselves by skilful distinctions, we can recognize in the well-known and frequently-mentioned business of reading a confused handwriting. We aim to weaken our sense-perception in favor of our imagination, i.e. so to reduce the clearness of the former as to be able to test upon it in some degree a larger number of images. We hold the MS. away from us, look at it askant, with contracted eyebrows, in different lights, and finally we read it. Again, the converse occurs. If we have seen something with a magnifying glass we later recognize details without its help. Definite conditions may bring to light very great distinctions. A body close to the face or in the middle distance looks different according as one eye or both be used in examining it. This is an old story and explains the queer descriptions we receive of such objects as weapons and the like, which were suddenly held before the face of the deponent. In cases of murderous assault it is certain that most uncanny stories are told, later explained by fear or total confusion or intentional dishonesty, but really to be explained by nothing more than actual optical processes.

I do not believe that binocular vision is of much importance in the law; I know of no case in ordinary vision where it matters whether one or both eyes have been used. It is correct to assert that one side or the other of a vertically held hand will be clearer if, before looking at it with both eyes, you look at it with one or the other, but this makes little difference to our purpose. It must be maintained that a part of what we see is seen with one eye only,—if, e.g., I look at the sky and cover one eye with my hand, a certain portion of the heaven disappears, but I observe no alteration in the remaining portion. When I cover the other eye, other stars disappear. Therefore, in binocular vision certain things are seen with one eye only. This may be of importance when an effect has been observed first with both eyes, then with one; raising the question of the difference in observation—but such a question is rare.

There are two additional things to consider. The first is the problem of the influence of custom on increasing visual power in darkness. This power is as a rule undervalued. No animal, naturally, can see anything in complete darkness. But it is almost unbelievable how much can be seen with a very little light. Here again, prisoners tell numerous stories concerning their vision in subterranean prisons. One saw so well as to be able to throw seven needles about the cell and then to find them again. Another, the naturalist Quatremére-Disjonval, was able so accurately to observe the spiders in his cell as to make the observation the basis for his famous “Aranéologie.” Aubert tells of his having had to stay in a room so dark as to make it necessary for others to feel their way, but nevertheless being able to read books without detection because the others could not see the books.

How quickly we get used to darkness and how much more we see after a while, is well known. It is also certain that the longer you are in darkness the more you see. You see more at the end of a day than after a few hours, and at the end of a year, still more. The eye, perhaps, changes in some degree for just this purpose. But a prolonged use of the visual mechanism tends to hypertrophy—or atrophy, as the eyes of deep-sea fishes show. It is well, in any event, to be careful about contradicting the testimonies of patients who have long lived in the dark, concerning what they have seen. The power to see in the dark is so various that without examination, much injustice may be done. Some people see almost nothing at twilight, others see at night as well as cats. And in court these differences must be established and experimentally verified.

The second important element is the innervation of the muscles in consequence of movement merely seen. So Stricker points out, that the sight of a man carrying a heavy load made him feel tension in the muscles involved, and again, when he saw soldiers exercising, he almost was compelled openly to act as they. In every case the muscular innervation followed the visual stimulus.

This may sound improbable but, nevertheless, everybody to some degree does the identical things. And at law the fact may be of importance in cases of assault and battery. Since I learned it, I have repeatedly observed in such cases, from harmless assault to murder, that people, although they had not been seen to deal any blows, were often accused of complicity simply because they were making suspicious movements that led to the following inference: “They stuck their hands into their trousers pocket looking for a knife, clenched their fists, looked as if they were about to jump, swung their hands.” In many such cases it appeared that the suspects were harmless spectators who were simply more obvious in their innervation of the muscles involved in the assault they were eagerly witnessing. This fact should be well kept in mind; it may relieve many an innocent.

Section 38. (2) Color Vision.

Concerning color vision only a few facts will be mentioned: 1. It will be worth while, first of all, to consider whether color exists. Liebmann holds that if all the people were blind to red, red would not exist; red, i.e., is some cervical phantasy. So are light, sound, warmth, taste, etc. With other senses we have another world. According to Helmholtz, it is senseless to ask whether cinnabar is red as we see it or is only so as an optical illusion. “The sensation of red is the normal reaction of normally constructed eyes to light reflected from cinnabar. A person blind to red, will see cinnabar as black, or a dark grayish yellow, and this is the correct reaction for these abnormal eyes. But he needs to know that his eyes are different from those of other people. In itself the sensation is neither more correct nor less correct than any other even though those who can see red are in the great majority. The red color of cinnabar exists as such only in so far as there are eyes which are similar to those of the majority of mankind. As such light reflected from cinnabar may not properly be called red; it is red only for especial kinds of eyes.” This is so unconditionally incorrect that an impartial judge of photography says[179] that everything that normal eyes call violet and blue, is very bright, and everything they call green and red is very dark. The red-blind person will see as equal certain natural reds, greens and gray-yellows, both in intensity and shadow. But on the photograph he will be able to distinguish the differences in brightness caused by these three otherwise identical colors. We may, therefore, assume that colors possess objective differences, and that these objective differences are perceived even by persons of normal vision. But whether I am able to sense the same effect in red that another senses, and whether I should not call red blue, if I had the color-vision of another, is as impossible to discover as it is useless. When the question of color is raised, therefore, we will try to discover only whether the person in question has normal color-vision, or what the nature and degree of his abnormality may be.

2. It is not unimportant to know whether single tints are recognizable in the distance. There have been several examinations of this fact. Aubert[180] constructed double squares of ten millimeters and determined the angle of vision at which the color as such could be seen. His results were:

COLOR OF THE SQUARE WHITE BACKGROUND BLACK

White 39´´

Red 1´ 43´´ 59´´

Light Green 1´ 54´´ 1´ 49´´

Dirty Red 3´ 27´´ 1´ 23´´

Blue 5´ 43´´ 4´ 17´´

Brown 4´ 55´´ 1´ 23´´

Light Blue 2´ 17´´ 1´ 23´´

Orange 1´ 8´´ 0´ 39´´

Gray 4´ 17´´ 1´ 23´´

Rose 2´ 18´´ 3´ 49´´

Yellow 3´ 27´´ 0´ 39´´

It is interesting to notice that the angle for blue on a white background is almost nine times that for white, orange, or yellow on a black background. In cases where colors are of importance, therefore, it will be necessary to discover the color and the nature of its background before the accuracy of the witness can be established.

3. It is well known that in the diminution of brightnesses red disappears before blue, and that at night, when all colors have disappeared, the blue of heaven is still visible. So if anybody asserts that he has been able to see the blue of a man’s coat but not his red-brown trousers, his statement is possibly true, while the converse would be untrue. But there are no reliable or consonant accounts of the order in which colors disappear in increasing darkness. The knowledge of this order would help a great deal in the administration of criminal justice.

4. The retina will not see red at the periphery, because there are no red rods there. A stick of red sealing wax drawn across the eye from right to left, appears at the periphery of the visual field to be black. If, then, a witness has not looked right at a definitely red object, and has seen it askance, he has certainly not observed its color. The experiment may be made by anybody.

5. According to Quantz[181] objects in less refractable colors (red, orange, yellow, and purple) look 0.2 to 3.6% bigger against white, while blue, blue-green, and violet objects appear from 0.2 to 2.2% smaller. Dark and long-lined objects seem longer; bright and horizontal seem wider. And these facts are significant when witnesses judge of size.

6. If colors are observed through small openings, especially through very small holes, the nuances become essentially different and green may even seem colorless.

7. According to Aubert, sparkle consists of the fact that one point in a body is very bright while the brightness diminishes almost absolutely from that point; e.g., a glancing wire has a very narrow bright line with deep shadows on each side; a ball of mercury in a thermometer, a shining point and then deep shadow. When we see this we say it sparkles because we unite it with a number of similar observations. It is therefore conceivable that at a great distance, under conditions of sharp or accidental illuminations, etc., we are likely to see things as sparkling which do not do so in the least. With the concept “sparkling,” moreover, we tend to unite, at least under certain circumstances, definite images, and hence “glancing weapons” are often seen in places where there were only quite harmless dull objects. So also coins are seen to sparkle where really there are none.

Section 39. (3) The Blind Spot.

Everybody knows what the blind spot is, and every psychology and physiology text-book talks about it. But as a rule it is identified only with the little point and the tiny cross pictured in the text-books, and it is supposed that it does not much matter if the little cross, under certain circumstances, can not be seen. But it must not be forgotten that the size of the blind spot increases with the distance so that at a fairly great distance, possibly half the length of a room, the blind spot becomes so great that a man’s head may disappear from the field of vision. According to Helmholtz: “The effect of the blind spot is very significant. If we make a little cross on a piece of paper and then a spot the size of a pea two inches to the right, and if we look at the cross with the left eye closed, the spot disappears. The size of the blind spot is large enough to cover in the heavens a plate which has twelve times the diameter of the moon. It may cover a human face at a distance of 6´, but we do not observe this because we generally fill out the void. If we see a line in the place in question, we see it unbroken, because we know it to be so, and therefore supply the missing part.”

A number of experiments have been made with more or less success to explain the blind spot. It is enough for us to agree that we see habitually with both eyes and that the “spot as big as a pea” disappears only when we look at the cross. But when we fix our eyes on anything we pay attention to that only and to nothing else. And it is indifferent to us if an uninteresting object disappears, so that the moment we begin to care about the “spot as large as a pea,” it is immediately to hand and needs no imaginative completion. If it be objected that fixing with the eyes and being interested are not identical, we reply that a distinction is made only in experiment. You fix one point and are interested in the other because you expect it to disappear. And this experiment, as anybody will immediately recognize, has its peculiar difficulty, because it requires much concentration not to look at the point which interests us. This never happens in the daily life, and it will not be easy to fix a point which is not interesting.

At the same time there are conceivable cases in which objects seen askance may be of importance, and where the visual fixation of a single point will not reveal every reflection that fell on the blind spot. I have not met with a practical case in which some fact or testimony could be explained only by the blind spot, but such cases are conceivable.

Section 40. (c) The Sense of Hearing.

We have two problems with regard to sound—whether the witnesses have heard correctly, and whether we hear them correctly. Between both witnesses and ourselves there are again other factors. Correct comprehension, faithful memory, the activity of the imagination, the variety of influences, the degree of personal integrity; but most important is the consideration, whether the witness has heard correctly. As a general thing we must deny in most cases completely accurate reproduction of what witnesses have heard. In this connection dealing with questions of honor is instructive. If the question is the recall of slander the terms of it will be as various as the number of witnesses. We discover that the sense, the tendency of slander is not easily mistaken. At least if it is, I have not observed it. The witness, e.g., will confuse the words “scamp,” “cheat,” “swindler,” etc., and again the words: “ox,” “donkey,” “numbskull,” etc. But he will not say that he has heard “scamp” where what was said was “donkey.” He simply has observed that A has insulted B with an epithet of moral turpitude or of stupidity and under examination he inserts an appropriate term. Often people hear only according to meanings and hence the difficulty of getting them to reproduce verbally and directly something said by a third person. They always engage upon indirect narration because they have heard only the meaning, not the words. Memory has nothing to do with this matter, for when in examination, a witness is requested to reproduce directly what he has just heard, he will reproduce no more than the sense, not the words. Not to do so requires an unusual degree of intelligence and training.

Now if the witnesses only reproduced the actual meaning of what they heard, no harm would be done, but they tell us only what they suppose to be the meaning, and hence we get a good many mistakes. It does seem as if uneducated and half-educated people are able to shut their ears to all things they do not understand. Even purely sensory perception is organized according to intelligent capacity.

If this is kept in mind it will be possible correctly to interpret testimonies in those difficult instances in which one man narrates what he has heard from another concerning his own statement, and where it might be quite impossible to judge the nature and culture of this third person. There are a few other conditions to consider besides.

If we have to discover a person’s hearing power or his hearing power under definite conditions, it is best never to depend, in even slightly important cases, on vocal tests merely. The examination must be made by experts, and if the case is really subtle it must be made under the same circumstances of place and condition, and with the same people as in the original situation. Otherwise nothing certain can be learned.

The determination of auditory power is, however, insufficient, for this power varies with the degree any individual can distinguish a single definite tone among many, hear it alone, and retain it. And this varies not only with the individual but also with the time, the place, the voice, etc. In my bed-room, e.g., and in three neighboring rooms I have wall-clocks each of which is running. The doors of the room are open right and left. At night when everything is quiet, I can sometimes hear the ticking of each one of these clocks; immediately isolate one completely and listen to that so that the ticking of the other three completely disappears. Then again I may kindly command myself not to hear this ticking, but to hear one of the other three, and I do so, though I fail to hear two clocks together at just the same instant. On another day under similar circumstances I completely fail in this attempt. Either I hear none of the clocks in particular, or only for a short time, which results in the ticking’s being again lost in the general noise; or I do hear the ticking of one clock, but never of that which I have chosen to hear.

This incident is variously explicable and the experiment may be repeated with various persons. It indicates that auditory capacity is exceedingly differentiated and that there is no justification for aprioristic doubt of especial powers. It is, however, admittedly difficult to say how experiments can be made under control.

There are still a few more marvels. It is repeatedly asserted, e.g., by Tyndall, that a comparatively large number of people do not hear high tones like the chirping of crickets, although the normal hearing of such people is acute. Others again easily sense deep tones but distinguish them with difficulty because they retain only a roll or roar, but do not hear the individual tones.[182] And generally, almost all people have difficulty in making a correct valuation of the direction of sound. Wundt says that we locate powerful sounds in front of us and are generally better able to judge right and left than before and behind.[183] These data, which are for us quite important, have been subjected to many tests. Wundt’s statement has been confirmed by various experiments which have shown that sound to the right and the left are best distinguished, and sounds in front and below, in front to the right and to the left, and below, to the right and to the left, are least easily distinguished. Among the experimenters were Preyer, Arnheim, Kries, Münsterberg.

All these experiments indicate certain constant tendencies to definite mistakes. Sounds in front are often mistaken for sounds behind and felt to be higher than their natural head-level. Again, it is generally asserted that binaural hearing is of great importance for the recognition of the direction of sound. With one ear this recognition is much more difficult. This may be verified by the fact that we turn our heads here and there as though to compare directions whenever we want to make sure of the direction of sound. In this regard, too, a number of effective experiments have been made.

When it is necessary to determine whether the witness deposes correctly concerning the direction of sound, it is best to get the official physician to find out whether he hears with both ears, and whether he hears equally well with both. It is observed that persons who hear excellently with both ears are unfortunate in judging the direction of sound. Others again are very skilful in this matter, and may possibly get their skill from practice, sense of locality, etc. But in any case, certainty can be obtained only by experimentation.

With regard to the conduction of sound—it is to be noted that sound is carried astonishingly far by means of compact bodies. The distance at which the trotting of horses, the thunder of cannons, etc., may be heard by laying the ear close to the ground is a common-place in fiction. Therefore, if a witness testifies to have heard something at a great distance in this way, or by having laid his ear to the wall, it is well not to set the evidence aside. Although it will be difficult in such cases to make determinative experiments, it is useful to do so because the limits of his capacity are then approximated.

Under certain circumstances it may be of importance to know what can be heard when the head, or at least the ear, is under water. The experiment may be made in the bath-room, by setting the back of the head under water so that the ears are completely covered but the mouth and the eyes are free. The mouth must be kept closed so that there shall be no intrusion of sound through the Eustachian tube. In this condition practically no sound can be heard which must first pass through the air. If, therefore, anybody even immediately next to you, speaks ever so loud, you can hear only a minimum of what he says. On the other hand, noises that are conducted by compact bodies, i.e. the walls, the bath, and the water, can be heard with astonishing distinctness, especially if the bath is not detachable but is built into the wall. Then if some remote part of the building, e.g. some wall, is knocked, the noise is heard perfectly well, although somebody standing near the bath hears nothing whatever. This may be of importance in cases of accident, in certain attempts at drowning people, and in accidental eaves-dropping.

There are several things to note with regard to deaf persons, or such as have difficulty with their hearing. According to Fechner, deafness begins with the inability to hear high tones and ends with the inability to hear deep ones, so that it often happens that complainants are not believed because they still hear deep tones. Again, there are mistakes which rise from the fact that the deaf often learn a great deal from the movements of the lips, and the reading of these movements has become the basis of the so-called “audition” of deaf mutes. There are stories of deaf mutes who have perceived more in this way, and by means of their necessary and well-practised synthesis of impressions, than persons with good hearing power.

The differences that age makes in hearing are of importance. Bezold has examined a large number of human ears of different ages and indicates that after the fiftieth year there is not only a successive decrease in the number of the approximately normal-hearing, but there is a successively growing increase in the degree of auditory limitation which the ear experiences with increasing age. The results are more surprising than is supposed.

Not one of 100 people over fifty years of age could understand conversational speech at a distance of sixteen meters; 10.5% understood it at a distance of eight to sixteen meters. Of school children 46.5% (1918 of them) from seven to eighteen understood it at a distance of 20 meters plus, and 32.7% at a distance of from 16 to 8 meters. The percentage then is 10.5 for people over fifty as against 79.2 of people over seven and under 18. Old women can hear better than old men. At a distance of 4 to 16 meters the proportion of women to men who could hear was 34 to 17. The converse is true of children, for at a distance of 20 meters and more the percentage of boys was 49.9 and girls 48.2. The reason for this inversion of the relation lies in the harmful influences of manual labor and other noisy occupations of men. These comparisons may be of importance when the question is raised as to how much more a witness may have heard than one of a different age.

Section 41. (d) The Sense of Taste.

The sense of taste is rarely of legal importance, but when it does come into importance it is regularly very significant because it involves, in the main, problems of poisoning. The explanation of such cases is rarely easy and certain—first of all, because we can not, without difficulty, get into a position of testing the delicacy and acuteness of any individual sense of taste, where such testing is quite simple with regard to seeing and hearing. At the same time, it is necessary when tests are made, to depend upon general, and rarely constant impressions, since very few people mean the same thing by, stinging, prickly, metallic, and burning tastes, even though the ordinary terms sweet, sour, bitter, and salty, may be accepted as approximately constant. The least that can be done when a taste is defined as good, bad, excellent, or disgusting, is to test it in every possible direction with regard to the age, habits, health, and intelligence of the taster, for all of these exercise great influence on his values. Similarly necessary are valuations like flat, sweetish, contractile, limey, pappy, sandy, which are all dictated by almost momentary variations in well-being.

But if any denotation is to be depended upon, and in the end some one has to be, it is necessary to determine whether the perception has been made with the end or the root of the tongue.[184] Longet, following the experiments of certain others, has brought together definite results in the following table:

TASTE TONGUE-TIP TONGUE ROOT

Glauber’s salts salty bitter

Iodkalium “ “

Alum sour sweet

Glycerine none “

Rock candy “ “

Chlorate of strychnine “ “

Natrium carbonate “ alkaloid

In such cases too, particularly as diseased conditions and personal idiosyncrasies exercise considerable influences, it will be important to call in the physician. Dehn is led by his experiments to the conclusion that woman’s sense of taste is finer than man’s, and again that that of the educated man finer than that of the uneducated. In women education makes no difference in this regard.

Section 42. (e) The Sense of Smell.

The sense of smell would be of great importance for legal consideration if it could get the study it deserves. It may be said that many men have more acute olfactory powers than they know, and that they may learn more by means of them than by means of the other senses. The sense of smell has little especial practical importance. It only serves to supply a great many people with occasional disagreeable impressions, and what men fail to find especially necessary they do not easily make use of. The utility of smell would be great because it is accurate, and hence powerful in its associative quality. But it is rarely attended to; even when the associations are awakened they are not ascribed to the sense of smell but are said to be accidental. I offer one example only, of this common fact. When I was a child of less than eight years, I once visited with my parents a priest who was a school-mate of my father’s. The day spent in the parsonage contained nothing remarkable, so that all these years I have not even thought of it. A short time ago all the details I encountered on that day occurred to me very vividly, and inasmuch as this sudden memory seemed baseless, I studied carefully the cause of its occurrence, without success. A short time later I had the same experience and at the same place. This was a clew, and I then recalled that I had undertaken a voyage of discovery with the small niece of the parson and had been led into a fruit cellar. There I found great heaps of apples laid on straw, and on the wall a considerable number of the hunting boots of the parson. The mixed odors of apple, straw and boots constituted a unique and long unsmelled perfume which had sunk deep into my memory. And as I passed a room which contained the same elements of odor, all those things that were associated with that odor at the time I first smelt it, immediately recurred.

Everybody experiences such associations in great number, and in examinations a little trouble will bring them up, especially when the question deals with remote events, and a witness tells about some “accidental” idea of his. If the accident is considered to be an association and studied in the light of a memory of odor, one may often succeed in finding the right clew and making progress.

But accurate as the sense of smell is, it receives as a rule little consideration, and when some question concerning smell is put the answer is generally negative. Yet in no case may a matter be so easily determined as in this one; one may without making even the slightest suggestion, succeed in getting the witness to confess that he had smelled something. Incidentally, one may succeed in awakening such impressions as have not quite crossed the threshold of consciousness, or have been subdued and diverted. Suppose, e.g., that a witness has smelled fire, but inasmuch as he was otherwise engaged was not fully conscious of it or did not quite notice it, or explained it to himself as some kitchen odor or the odor of a bad cigar. Such perceptions are later forgotten, but with proper questioning are faithfully and completely brought to memory.

Obviously much depends on whether anybody likes certain delicate odors or not. As a rule it may be held that a delicate sense of smell is frequently associated with nervousness. Again, people with broad nostrils and well developed foreheads, who keep their mouths closed most of the time, have certainly a delicate sense of smell. People of lymphatic nature, with veiled unclear voices, do not have a keen sense of smell, and still duller is that of snufflers and habitual smokers. Up to a certain degree, practice may do much, but too much of it dulls the sense of smell. Butchers, tobacconists, perfumers, not only fail to perceive the odors which dominate their shops; their sense of smell has been dulled, anyway. On the other hand, those who have to make delicate distinctions by means of their sense, like apothecaries, tea dealers, brewers, wine tasters, etc. achieve great skill. I remember that one time when I had in court to deal almost exclusively with gypsies, I could immediately smell whether any gypsies had been brought there during the night.

Very nervous persons develop a delicateness and acuteness of smell which other persons do not even imagine. Now we have no real knowledge of how odors arise. That they are not the results of the radiation of very tiny parts is shown by the fact that certain bodies smell though they are known not to give off particles. Zinc, for example, and such things as copper, sulphur, and iron, have individual odors; the latter, particularly when it is kept polished by a great deal of friction,—e.g., in the cases of chains, key-rings kept in the pocket.

In defining the impressions of smell great difficulties occur. Even normal individuals often have a passionate love for odors that are either indifferent or disgusting to others (rotten apples, wet sponges, cow-dung, and the odor of a horse-stable, garlic, assafoetida, very ripe game, etc.). The same individual finds the odor of food beautiful when hungry, pleasant when full-fed, and unendurable when he has migraine. It would be necessary to make an accurate description of these differences and all their accompanying circumstances. With regard to sex, the sense of smell, according to Lombroso,[185] is twice as fine in men as in women. This is verified by Lombroso’s pupils Ottolenghi and Sicard, Roncoroni and Francis Galton. Experience of daily life does not confirm this, though many smokers among men rarely possess acute sense of smell, and this raises the percentage considerably in favor of women.

Section 43. (f) The Sense of Touch.

I combine, for the sake of simplicity, the senses of location, pressure, temperature, etc., under the general expression: sense of touch. The problem this sense raises is no light one because many witnesses tell of perceptions made in the dark or when they were otherwise unable to see, and because much is perceived by means of this sense in assaults, wounds, and other contacts. In most cases such witnesses have been unable to regard the touched parts of their bodies, so that we have to depend upon this touch-sense alone. Full certainty is possible only when sight and touch have worked together and rectified one another. It has been shown that the conception of the third dimension can not be obtained through the sense of sight. At the beginning we owe the perception of this dimension only to touch and later on to experience and habit. The truth of this statement is confirmed by the reports of persons who, born blind, have gained sight. Some were unable to distinguish by means of mere sight a silver pencil-holder from a large key. They could only tell them to be different things, and recognized their nature only after they had felt them. On the other hand, the deceptive possibilities in touch are seen in the well-known mistakes to which one is subjected in blind touching. At the same time practice leads to considerable accuracy in touch and on many occasions the sense is trusted more than sight—e.g., whenever we test the delicacy of an object with our finger-tips. The fineness of paper, leather, the smoothness of a surface, the presence of points, are always tested with the fingers. So that if a witness assures us that this or that was very smooth, or that this surface was very raw, we must regularly ask him whether he had tested the quality by touching it with his fingers, and we are certain only if he says yes. Whoever has to depend much on the sense of touch increases its field of perception, as we know from the delicacy of the sense in blind people. The statements of the blind concerning their contact sensations may be believed even when they seem improbable; there are blind persons who may feel the very color of fabrics, because the various pigments and their medium give a different surface-quality to the cloth they color.

In another direction, again, it is the deaf who have especial power. So, we are assured by Abercrombie that in his medical practice he had frequently observed how deaf people will perceive the roll of an approaching wagon, or the approach of a person, long before people with good hearing do so. For a long time I owned an Angora which, like all Angoras, was completely deaf, and her deafness had been tested by physicians. Nevertheless, if the animal was dozing somewhere and anybody came near it, she would immediately notice his steps, and would distinguish them, for she would jump up frightened, if the newcomer was unknown, and would stretch herself with pleasure in the expectation of petting if she felt a friend coming. She would sense the lightest touch on the object she occupied, bench, window-seat, sofa, etc., and she was especially sensitive to very light scratching of the object. Such sensitivity is duplicated frequently in persons who are hard of hearing, and whom, therefore, we are likely to doubt.

The sense of touch is, moreover, improved not only by practice, but also by the training of the muscles. Stricker asserts that he has frequently noticed that the observational capacity of individuals who make much use of their muscles is greater than among persons whose habits are sedentary. This does not contradict the truth established by many experiments that the educated man is more sensitive in all directions than the uneducated. Again, women have a better developed sense of touch than men, the space-sense and the pressure-sense being equivalent in both sexes. On these special forms of the touch-sense injections of various kinds have decided influence. The injection of morphine, e.g., reduces the space-sense in the skin. Cannabinum tannicum reduces sensibility and alcohol is swift and considerable in its effects. According to Reichenbach some sensitives are extreme in their feeling. The best of them notice immediately the approach and relative position of people, or the presence of another in a dark room. That very nervous people frequently feel air pressure, fine vibrations, etc., is perfectly true. And this and other facts show the great variety of touch impressions that may be distinguished. The sense of temperature has a comparatively high development, and more so in women than in men. At the lips and with the tips of the fingers, differences of two-tenths of a degree are perceived. But where an absolute valuation and not a difference is to be perceived, the mean variation, generally, is not much less than 4 degrees. E.g., a temperature of 19 degrees R. will be estimated at from 17 to 21 degrees. I believe, however, that the estimation of very common temperatures must be accepted as correct. E.g., anybody accustomed to have his room in winter 14 degrees R. will immediately notice, and correctly estimate, the rise or fall of one degree. Again, anybody who takes cold baths in summer will observe a change of one degree in temperature. It will, therefore, be possible to believe the pronouncements of witnesses concerning a narrow range of temperatures, but all the conditions of perception must be noted for the differences are extreme. It has been shown, e.g., that the whole hand finds water of 29 degrees R. warmer than water of 32 degrees R. which is merely tested with the finger. Further, Weber points out,[186] “If we put two adjacent fingers into two different warm fluids the sensations flow together in such a way that it is difficult to distinguish differences. But if we use two hands in this test, it is especially successful when we change the hands from one fluid to another. The closer the points on the skin which receive contemporary impressions, and perhaps, the closer the portions of the brain to which these impressions are sent, the more easily these sensations flow together; while again, the further they are from one another the less frequently does this occur.” In the practice of criminal law such matters will rarely arise, but estimations of temperature are frequently required and their reliability must be established.

It is important to know what a wounded man and his enemy feel in the first instant of the crime and in what degree their testimonies are reliable. First of all, we have to thank the excellent observations of Weber, for the knowledge that we find it very difficult to discover with closed eyes the angle made by a dagger thrust against the body. It is equally difficult to determine the direction from which a push or blow has come. On the other hand we can tell very accurately in what direction a handful of hair is pulled.

With regard to the time it takes to feel contact and pain, it is asserted that a short powerful blow on a corn is felt immediately, but the pain of it one to two seconds later. It may be that corns have an especial constitution, but otherwise the time assigned before feeling pain is far too long. Helmholtz made 1850 measurements which proved that the nervous current moves 90 feet a second. If, then, you prick your finger, you feel it a thirtieth of a second later. The easiest experiments which may be made in that regard are insufficient to establish anything definite. We can only say that the perception of a peripheral pain occurs an observable period after the shock, i.e., about a third of a second later than its cause.

The sensation of a stab is often identified as contact with a hot object, and it is further asserted that the wounded person feels close to the pain which accompanies the push or the cut, the cold of the blade and its presence in the depths of his body. So far as I have been able to learn from wounded people, these assertions are not confirmed. Setting aside individuals who exaggerate intentionally and want to make themselves interesting or to indicate considerable damage, all answers point to the fact that stabs, shots, and blows are sensed as pushes. In addition, the rising of the blood is felt almost immediately, but nothing else; pain comes much later. It is asserted by couleur-students[187] who have occasion to have a considerable number of duels behind them, that “sitting thrusts,” even when they are made with the sharpest swords, are sensed only as painless, or almost painless, blows or pushes. Curiously enough all say that the sensation is felt as if caused by some very broad dull tool: a falling shingle, perhaps. But not one has felt the cold of the entering blade.

Soldiers whose shot wounds were inquired into, often just a few minutes after their being wounded, have said unanimously that they had felt only a hard push.

It is quite different with the man who causes the wound. Lotze has rightly called attention to the fact that in mounting a ladder with elastic rungs one perceives clearly the points at which the rungs are fastened to the sides. The points at which an elastic trellis is fastened is felt when it is shaken, and the resistance of the wood when an axe is used on it. In the same way the soldier senses clearly the entrance of his sword-point or blade into the body of his enemy. The last fact is confirmed by the students. One can clearly distinguish whether the sword has merely beaten through the skin or has sunk deeply and reached the bone. And this sensation of touch is concentrated in the right thumb, which is barely under the hilt of the sword at the point where the grip rests.

The importance of the fact that the wounder feels his success lies in the possibility it gives him, when he wants to tell the truth, to indicate reliably whether and how far he has wounded his opponent. The importance of the testimony of the wounded man lies in its influence on determining, in cases where there were more than one concerned in the assault, which wound is to be assigned to which man. We often hear from the victim who really desires to tell the truth, “I was quite convinced that X dealt me the deep stab in the shoulder, but he has only pushed and not stabbed me—I did not perceive a stab.” Just the same, it was X who stabbed him, and if the examining judge explains the matter to the victim, his testimony will be yet more honest.

There are still a few other significant facts.

1. It is well known that the portion of the skin which covers a bone and which is then so pulled away that it covers a fleshy part, can not easily identify the point of stimulation. Such transpositions may be made intentionally in this experiment, but they occur frequently through vigorous twists of the body. When the upper part of the body is drawn backwards, while one is sitting down, a collection of such transpositions occur and it is very hard then to localize a blow or stab. So, too, when an arm is held backward in such a way as to turn the flat of the hand uppermost. It is still more difficult to locate a wound when one part of the body is held by another person and the skin pulled aside.

2. The sensation of wetness is composed of that of cold and easy movement over surface. Hence, when we touch without warning a cold smooth piece of metal, we think that we are touching something wet. But the converse is true for we believe that we are touching something cold and smooth when it is only wet. Hence the numerous mistakes about bleeding after wounds. The wounded man or his companions believe that they have felt blood when they have only felt some smooth metal, or they have really felt blood and have taken it for something smooth and cold. Mistakes about whether there was blood or not have led to frequent confusion.

3. Repetition, and hence summation, intensifies and clarifies the sensation of touch. As a consequence, whenever we want to test anything by touching it we do so repeatedly, drawing the finger up and down and holding the object between the fingers; for the same reason we repeatedly feel objects with pleasant exteriors. We like to move our hands up and down smooth or soft furry surfaces, in order to sense them more clearly, or to make the sensation different because of its duration and continuance. Hence it is important, every time something has to be determined through touch, to ask whether the touch occurred once only or was repeated. The relation is not the same in this case as between a hasty glance and accurate survey, for in touching, essential differences may appear.

4. It is very difficult to determine merely by touch whether a thing is straight or crooked, flat, convex or concave. Weber has shown that a glass plate drawn before the finger in such wise as to be held weakly at first, then more powerfully, then again more powerfully seems to be convex and when the reverse is done, concave. Flatness is given when the distance is kept constant.

5. According to Vierordt,[188] the motion of a point at a constant rate over a sizable piece of skin, e.g., the back of the hand from the wrist to the finger tips, gives, if not looked at, the definite impression of increasing rapidity. In the opposite direction, the definiteness is less but increases with the extent of skin covered. This indicates that mistakes may be made in such wounds as cuts, scratches, etc.

6. The problem may arise of the reliability of impressions of habitual pressure. Weber made the earliest experiments, later verified by Fechner, showing that the sensation of weight differs a great deal on different portions of the skin. The most sensitive are the forehead, the temples, the eyelids, the inside of the forearm. The most insensitive are the lips, the trunk and the finger-nails. If piles of six silver dollars are laid on various parts of the body, and then removed, one at a time, the differences are variously felt. In order to notice a removal the following number must be taken away:

One dollar from the top of the finger, One dollar from the sole of the foot, Two dollars from the flat of the hand, Two dollars from the shoulder blade, Three dollars from the heel, Four dollars from the back of the head, Four dollars from the breast, Five dollars from the middle of the back, Five dollars from the abdomen.

Further examinations have revealed nothing new. Successful experiments to determine differences between men and women, educated and uneducated, in the acuteness of the sense of pressure, have not been made. The facts they involve may be of use in cases of assault, choking, etc.

Topic 2. PERCEPTION AND CONCEPTION.

Section 44.

What lawyers have to consider in the transition from purely sensory impressions to intellectual conceptions of these impressions, is the possibility of later reproducing any observed object or event. Many so-called scientific distinctions have, under the impulse of scientific psychology, lost their status. Modern psychology does not see sharply-drawn boundaries between perception and memory, and suggests that the proper solution of the problem of perception is the solution of the problem of knowledge.[189]

With regard to the relation of consciousness to perception we will make the distinctions made by Fischer.[190] There are two spheres or regions of consciousness: the region of sensation, and of external perception. The former involves the inner structure of the organism, the latter passes from the organism into the objective world. Consciousness has a sphere of action in which it deals with the external world by means of the motor nerves and muscles, and a sphere of perception which is the business of the senses.

External perception involves three principal functions: apprehension, differentiation, and combination. Perception in the narrower sense of the term is the simple sensory conscious apprehension of some present object stimulating our eyes. We discover by means of it what the object is, its relation to ourselves and other things, its distance from us, its name, etc.

What succeeds this apprehension is the most important thing for us lawyers, i.e. recognition. Recognition indicates only that an object has sufficiently impressed a mind to keep it known and identifiable. It is indifferent what the nature of the recognized object is. According to Hume the object may be an enduring thing (“non-interrupted and non-dependent on mind”), or it may be identical with perception itself. In the latter case the perception is considered as a logical judgment like the judgment: “It is raining,” or the feeling that “it is raining,” and there recognition is only the recognition of a perception. Now judgments of this sort are what we get from witnesses, and what we have to examine and evaluate. This must be done from two points of view. First, from the point of view of the observer and collector of instances who is seeking to discover the principle which governs them. If this is not done the deductions that we make are at least unreliable, and in most cases, false. As Mach says, “If once observation has determined all the facts of any natural science, a new period begins for that science, the period of deduction.” But how often do we lawyers distinguish these two periods in our own work.[191]

The second point of importance is the presence of mistakes in the observations. The essential mistakes are classified by Schiel under two headings. Mistakes in observation are positive or negative, wrong observation or oversight. The latter occurs largely through preconceived opinions. The opponents of Copernicus concluded that the earth did not move because otherwise a stone dropped from the top of a tower would reach the ground a little to the west. If the adherents of Copernicus had made the experiment they would have discovered that the stone does fall as the theory requires. Similar oversights occur in the lawyer’s work hundreds of times. We are impressed with exceptions that are made by others or by ourselves, and give up some already tried approach without actually testing the truth of the exception which challenges it. I have frequently, while at work, thought of the story of some one of the Georges, who did not like scholars and set the following problem to a number of philosophers and physicists: “When I put a ten pound stone into a hundred pound barrel of water the whole weighs a hundred and ten pounds, but when I put a live fish of ten pounds into the barrel the whole still weighs only a hundred pounds?” Each one of the scholars had his own convincing explanation, until finally the king asked one of the foot-men, who said that he would like to see the experiment tried before he made up his mind. I remember a case in which a peasant was accused of having committed arson for the sake of the insurance. He asserted that he had gone into a room with a candle and that a long spider’s web which was hanging down had caught fire from it accidentally and had inflamed the straw which hung from the roof. So the catastrophe had occurred. Only in the second examination did it occur to anybody to ask whether spider’s web can burn at all, and the first experiment showed that that was impossible.

Most experiences of this kind indicate that in recognizing events we must proceed slowly, without leaping, and that we may construct our notions only on the basis of knowledge we already possess. Saint Thomas says, “Omnes cognitio fit secundum similitudinem cogniti in cognoscente.” If this bit of wisdom were kept in mind in the examination of witnesses it would be an easier and simpler task than usual. Only when the unknown is connected with the known is it possible to understand the former. If it is not done the witness will hardly be able to answer. He nowhere finds support, or he seeks one of his own, and naturally finds the wrong one. So the information that an ordinary traveler brings home is mainly identical with what he carries away, for he has ears and eyes only for what he expects to see. For how long a time did the negro believe that disease pales the coral that he wears? Yet if he had only watched it he would have seen how foolish the notion was. How long, since Adam Smith, did people believe that extravagance helps industry, and how much longer have people called Copernicus a fool because they actually saw the sun rise and set. So J. S. Mill puts his opinions on this matter. Benneke[192] adds, “If anybody describes to me an animal, a region, a work of art, or narrates an event, etc., I get no notion through the words I hear of the appearance of the subject. I merely have a problem set me by means of the words and signs, in the conception of the subject, and hence it depends for truth mainly upon the completeness of earlier conceptions of similar things or events, and upon the material I have imaginatively at hand. These are my perceptual capital and my power of representation.”

It naturally is not necessary to ask whether a narrator has ever seen the things he speaks of, nor to convince oneself in examination that the person in question knows accurately what he is talking about. At the same time, the examiner ought to be clear on the matter and know what attitude to take if he is going to deal intelligibly with the other. I might say that all of us, educated and uneducated, have apprehended and remember definite and distinct images of all things we have seen, heard, or learned from descriptions. When we get new information we simply attach the new image to the old, or extinguish a part of the old and put the new in its place, or we retain only a more or less vigorous breath of the old with the new. Such images go far back; even animals possess them. One day my small son came with his exciting information that his guinea pig, well known as a stupid beast, could count. He tried to prove this by removing the six young from their mother and hiding them so that she could not see what happened to them. Then he took one of the six, hid it, and brought the remaining five back to the old lady. She smelled them one after the other and then showed a good deal of excitement, as if she missed something. Then she was again removed and the sixth pig brought back; when she was restored to her brood, she sniffed all six and showed a great deal of satisfaction. “She could count at least six.” Naturally the beast had only a fixed collective image of her brood, and as one was missing the image was disturbed and incorrect. At the same time, the image was such as is created by the combination of events or circumstances. It is not far from the images of low-browed humanity and differs only in degree from those of civilized people.