According to Berkeley and Hume recognition is not directed upon a different object, nor does it presuppose one; the activity of recognition consists either in the exhibition or the creation of the object. Recognition lends the idea an independence which does not belong to it and in that way turns it into a thing, objectifies it, and posits it as substantial. Maudsley makes use of the notion that it is possible to represent any former content of consciousness as attended to so that it may again come into the center of the field of consciousness. Dorner[3] explains recognition as follows: "The possible is not only the merely possible in opposition to the actual; it is much more proper to conceive being as possible, i. e., as amenable to logical thinking; without this there could be no recognition." Klpe[4] concerns himself with the problem of the difference between perceptive images and memory images and whether the latter are only weaker than the former as English philosophers and psychologists a.s.sert. He concludes that they are not so.[3] H Dorner: Das menschliche Erkennen. Berlin 1877.[4] O. Klpe: Grundriss der Psychologie. Leipzig 1893.When we take all these opinions concerning memory together we conclude that neither any unity nor any clear description of the matter has been attained. Ebbinghaus's sober statement may certainly be correct: "Our knowledge of memory rises almost exclusively from the observation of extreme, especially striking cases. Whenever we ask about more special solutions concerning the detail of what has been counted up, and their other relations of dependence, their structure, etc., there are no answers."

n.o.body has as yet paid attention to the simple daily events which const.i.tute the routine of the criminalists. We find little instruction concerning them, and our difficulties as well as our mistakes are thereby increased. Even the modern repeatedly cited experimental investigations have no direct bearing upon our work.We will content ourselves with viewing the individual conceptions of memory and recollection as occurring in particular cases and with considering them, now one, now the other, according to the requirements of the case. We shall consider the general relation of "reproduction" to memory. "Reproduction" we shall consider in a general sense and shall subsume under it also the so-called involuntary reproductions which rise in the forms and qualities of past events without being evoked, i. e., which rise with the help of unconscious activity through the more or less independent a.s.sociation of ideas. Exactly this unconscious reproduction, this apparently involuntary activity, is perhaps the most fruitful, and we therefore unjustly meet with unexceptionable distrust the later sudden "occurrence," especially when these occurrences happen to defendant and his witnesses. It is true that they frequently deceive us because behind the sudden occurrence there often may be nothing more than a better training and instruction from experienced cell-mates; though very often the circ.u.mstances are such that the suspect has succeeded through some released prisoner, or by a blackened letter, in sending a message from his prison, by means of which false witnesses of alibi, etc., are provided. Distrust is in any event justified, when his most important witnesses suddenly "occur" to the accused. But this does not always happen, and we find in our own experience evidence of the fact that memory and the capacity to recall something often depend upon health, feeling, location, and chance a.s.sociations which can not be commanded, and happen as accidentally as anything in life can. That we should remember anything at all depends upon the point of time. Everybody knows how important twilight may be for memory. Indeed, twilight has been called the visiting-hour of recollection, and it is always worth while to observe the situation when anybody a.s.serts that some matter of importance occurred to him in the twilight. Such an a.s.sertion merits, at least, further examination. Now, if we only know how these occurrences const.i.tute themselves, it would not be difficult to study them out and to estimate their probability. But we do not know, and we have to depend, primarily, on observation and test. Not one of the theories applied is supported by experience altogether.They may be divided into three essential groups.1. What is received, fades away, becomes a "trace," and is more or less overlaid by new perceptions. When these latter are ever set aside, the old trace comes into the foreground.2. The ideas sink, darken, and disintegrate. If they receive support and intensification they regain complete clearness.3. The ideas crumble up, lose their parts. When anything occurs that reunites them and restores what is lost, they become whole again.Ebbinghaus maintains, correctly enough, that not one of these explanations is universally satisfactory, but it must be granted that now one, now another is useful in controlling this or that particular case. The processes of the destruction of an idea, may be as various as those of the destruction and restoration of a building. If a building is destroyed by fire, I certainly can not explain the image given by merely a.s.suming that it was the victim of the hunger of time. A building which has suffered because of the sinking of the earth I shall have to image by quite other means than those I would use if it had been destroyed by water.For the same reason when, in court, somebody a.s.serts a sudden "occurrence," or when we want to help him and something occurs to him, we shall have to proceed in different fashion and determine our action empirically by the conditions of the moment. We shall have to go back, with the help of the witness, to the beginning of the appearance of the idea in question and study its development as far as the material permits us. In a similar manner we must make use of every possibility of explanation when we are studying the disappearance of ideas. At one point or another we shall find certain connections. One chief mistake in such reconstructive work lies in overlooking the fact that no individual is merely pa.s.sive when he receives sensations; he is bound to make use of a certain degree of activity. Locke and Bonnet have already mentioned this fact, and anybody may verify it by comparing his experiments of trying to avoid seeing or hearing, and trying actively to see or to hear. For this reason it is foolish to ask anybody how it happened that he perceived less than another, because both have equally good senses and were able to perceive as much. On the other hand, the grade of activity each has made use of in perception is rarely inquired into, and this is the more unfortunate because memory is often propor- tionate to activity. If, then, we are to explain how various statements concerning contemporaneous matters, observed a long time ago, are to be combined, it will not be enough to compare the memory, sensory acuteness, and intelligence of the witnesses. The chief point of attention should be the activity which has been put in motion during the sense-perception in question.Section 53. (b) The Forms of Reproduction.Kant a.n.a.lyzes memory: 1. As apprehending something in memory.2. As retaining it for a long time.3. As immediately recalling it.One might, perhaps add, as 4: that the memory-image is most conformable to the actual one. This is not identical with the fact that we recollect at all. It is to be a.s.sumed that the forms of memory- images vary very much with different persons, because each individual verifies his images of various objects variously. I know two men equally well for an equal time, and yet have two memory- images of them. When I recall one, a life-sized, moving, and moved figure appears before me, even the very man himself; when I think of the other, I see only a small, bare silhouette, foggy and colorless, and the difference does not require that the first shall be an interesting and the second a boresome individual. This is still clearer in memory of travels. One city appears in recollection with size, color and movement, real; the other, in which I sojourned for the same length of time and only a few days later, under similar conditions of weather, etc., appears like a small, flat photograph. Inquiry reveals that this is as true of other people as of me, and that the problem of memory is much differentiated by the method of recollection. In fact, this is so little in doubt that at some periods of time there are more images of one sort than of another and what is a rule for one kind of individual is an exception for another.Now there is a series of phenomena for which we possess particular types of images which often have little to do with the things themselves. So Exner says: "We might know the physiognomy of an individual very accurately, be able to pick him out among a thousand, without being clear about the differences between him and another; indeed, we often do not know the color of his eyes and hair, yet marvel when it suddenly becomes different."Kries[1] calls attention to another fact: "When we try to mark in memory the contour of a very well-known coin, we deceive ourselves, unbelievably-when we see the coin the size we imagine it to be, we wonder still more."[1] v. Kries: BeitrLotze shows correctly that memory never brings back a blinding flash of light, or the over-powering blow of an explosion with the intensity of the image in proper relation to the impression. I believe that it is not necessary to go so far, for example, and hold that not even the sparkling of a star, the crack of a pistol, etc., are kept in memory with more than partial implication of the event. Maudsley points out correctly that we can have no memory of pain-"because the disturbance of nervous elements disappears just as soon as their integrity is again established." Perhaps, also, because when the pain has disappeared, the tertium comparationis is lacking. But one need not limit oneself to pain, but may a.s.sert that we lack memory of all unpleasant sensations. The first time one jumps into the water from a very high spring-board, the first time one's horse rises over a hurdle, or the first time the bullets whistle past one's ear in battle, are all most unpleasant experiences, and whoever denies it is deceiving himself or his friends. But when we think of them we feel that they were not so bad, that one merely was very much afraid, etc. But this is not the case; there is simply no memory for these sensations.This fact is of immense importance in examination and I believe that no witness has been able effectively to describe the pain caused by a body wound, the fear roused by arson, the fright at a threat, not, indeed, because he lacked the words to do so, but because he had not sufficient memory for these impressions, and because he has nothing to-day with which to compare them. Time, naturally, in such cases makes a great difference, and if a man were to describe his experiences shortly after their uncomfortable occurrence he would possibly remember them better than he would later on. Here, if the examiner has experienced something similar, years ago, he is likely to accuse the witness of exaggeration under the belief that his own experience has shown the thing to be not so bad. Such an accusation will be unjust in most instances. The differences in conception depend to a large degree on differences in time, and consequent fading in memory. Several other particular conditions may be added.Kant, e. g., calls attention to the power we have over our fancy: "In memory, our will must control our imagination and our imagina- tion must be able to determine voluntarily the reproduction of ideas of past time."But these ideas may be brought up not only voluntarily; we have also a certain degree of power in making these images clearer and more accurate. It is rather foolish to have the examiner invite the witness to "exert his memory, to give himself the trouble, etc." This effects nothing, or something wrong. But if the examiner is willing to take the trouble, he may excite the imagination of the witness and give him the opportunity to exercise his power over the imagination. How this is done depends naturally upon the nature and education of the witness, but the judge may aid him just as the skilful teacher may aid the puzzled pupil to remember. When the pianist has completely forgotten a piece of music that he knew very well, two or three chords may lead him to explicate these chords forward or backward, and then-one step after another-he reproduces the whole piece. Of course the chords which are brought to the mind of the player must be properly chosen or the procedure is useless.There are rules for the selection of these clews. According to Ebbinghaus: "The difference in the content of the recollected is due to discoverable causes. Melodies may become painful because of their undesirable obstinacy in return. Forms and colors do not usually recur, and if they do, they do so with noticeable claims on distinctness and certainty. Past emotional conditions are reproduced only with effort, in comparatively pallid schemes, and often only by means of the accompanying movements." We may follow these clews, in some directions at least, to our advantage. Of course, n.o.body will say that one should play tunes to witnesses in order to make them remember, because the tunes have sunk into the memory with such undesirable obstinacy as to be spurs to recollection. It is just as futile to operate with forms and colors, or to excite emotional conditions. But what has been said leads us back to the ancient rule of working so far as is possible with the constantly well-developed sense of location. Cicero already was aware of this "Tanta vis admonitionis inest in locis, id quidem infinitum in hac urbe, quoc.u.mque enim ingredimur, in aliquam historiam vestigium possumus." Indeed he deduces his whole doctrine of memory from the sense of location, or he at least justifies those who do so.If, then, we bring a witness, who in our court house recollects nothing, in loc.u.m rei sitae, all the mentioned conditions act favor- ably.[1] The most influential is the sense of location itself, inasmuch as every point at which something significant occurred not only is the content of an a.s.sociation, but is also the occasion of one. It is, moreover, to be remembered that reproduction is a difficult task, and that all unnecessary additional difficulties which are permitted to accrue, definitely hinder it. Here, too, there is only a definite number of units of psychical energy for use, and the number which must be used for other matters is lost to the princ.i.p.al task. If, e. g., I recall an event which had occurred near the window of a definite house, I should have considerable difficulty to recall the form of the house, the location of the window, its appearance, etc., and by the time this attempt has barely begun to succeed, I have made so much effort that there is not sufficient power left for the recollection of the event we are really concerned with. Moreover, a mistake in the recollection of extraneous objects and the false a.s.sociations thereby caused, may be very disturbing to the correctness of the memory of the chief thing. If, however, I am on the spot, if I can see everything that I had seen at the time in question, all these difficulties are disposed of.[1] Cf. Schneikert in H. Gross's Archiv, XIII, 193.We have still to count in the other conditions mentioned above. If acoustic effects can appear anywhere, they can appear in the locality where they first occurred. The same bell ringing, or a similar noise, may occur accidentally, the murmur of the brook is the same, the rustle of the wind, determined by local topography, vegetation, especially by trees, again by buildings, varies with the place. And even if only a fine ear can indicate what the difference consists of, every normal individual senses that difference unconsciously. Even the "universal noise," which is to be found everywhere, will be differentiated and characteristic according to locality, and that, together with all these other things, is extraordinarily favorable to the a.s.sociation of ideas and the reproduction of the past. Colors and forms are the same, similar orders may occur, and possibly the same att.i.tudes are awakened, since these depend in so great degree upon external conditions. Now, once these with their retrospective tendencies are given, the recollection of any contemporary event increases, as one might say, spontaneously. Whatever may especially occur to aid the memory of an event, occurs best at the place where the event itself happened, and hence, one can not too insistently advise the examination of witnesses, in important cases, only in loco rei sitae. Incidentally, the judge himself learns the real situation and saves himself, thereby, much time and effort, for he is enabled in a few words to render the circ.u.mstantial descriptions which have to be composed with so much difficulty when the things are not seen and must be derived from the testimonies of the witnesses themselves.Whoever does not believe in the importance of conducting the examination at the place of an event, needs only to repeat his examination twice, once at the court, and again at the place-then he certainly will doubt no more. Of course the thing should not be so done that the event should be discussed with the witness at the place of its occurrence and then the protocol written in the house of the mayor, or in an inn half an hour away-the protocol must to the very last stroke of the pen be written then and there, in order that every impression may be renewed and every smallest doubt studied and corrected. Then the differences between what has pa.s.sed, what has been later added, and what is found to-day can be easily determined by sticking to the rule of Uphues, that the recognition of the present as present is always necessary for the eventual recognition of the past. Kant has already suggested what surprising results such an examination will give: "There are many ideas which we shall never again in our lives be conscious of, unless some occasion cause them to spring up in the memory." But such a particularly powerful occasion is locality, inasmuch as it brings into play all the influences which our senses are capable of responding to.[1][1] Jost: ber GedOf course the possibility of artificially-stimulated memory disappears like all memory, with the lapse of time. As a matter of fact, we know that those of our experiences which concern particular persons and things, and which are recalled at the sight of those persons and things, become, later on, when the connections of images have been broken, capable only of awakening general notions, even though the persons or things are as absolutely present as before. But very unfavorable circ.u.mstances must have been at work before such a situation can develop.It is characteristic, as is popularly known, that memory can be intensified by means of special occasions. It is Hfler's opinion that the Spartan boys were whipped at the boundary stones of their country in order that they might recall their position, and even now-a-days our peasants have the custom, when setting up new boundary stones, of grasping small boys by the ears and hair in order that they shall the better remember the position of the new boundary mark when, as grown men, they will be questioned about it. This being the case, it is safer to believe a witness when he can demonstrate some intensely influential event which was contemporaneous with the situation under discussion, and which reminds him of that situation.Section 54. (c) The Peculiarities of Reproduction.The differences in memory which men exhibit are not, among their other human qualities, the least. As is well known, this difference is expressed not only in the vigor, reliability, and promptness of their memory, but also in the field of memory, in the accompaniment of rapid prehensivity by rapid forgetfulness, or slow prehensivity and slow forgetfulness, or in the contrast between narrow, but intense memory, and broad but approximate memory.Certain special considerations arise with regard to the field of greatest memory. As a rule, it may be presupposed that a memory which has developed with especial vigor in one direction has generally done this at the cost of memory in another direction. Thus, as a rule, memory for numbers and memory for names exclude each other. My father had so bad a memory for names that very frequently he could not quickly recall my Christian name, and I was his own son. Frequently he had to repeat the names of his four brothers until he hit upon mine, and that was not always a successful way.[1] When he undertook an introduction it was always: "My honored m-m-m,"-"The dear friend of my youth m-m-m." On the other hand, his memory for figures was astounding. He noted and remembered not only figures that interested him for one reason or another, but also those that had not the slightest connection with him, and that he had read merely by accident. He could recall instantaneously the population of countries and cities, and I remember that once, in the course of an accidental conversation, he mentioned the production of beetroot in a certain country for the last ten years, or the factory number of my watch that he had given me fifteen years before and had never since held in his hand. He often said that the figures he carried in his head troubled him. In this regard the symptom may be mentioned that he was not a good mathematician, but so exceptional a card player that n.o.body wanted to play with him. He noticed every single card dealt and could immediately calculate what cards each player had, and was able to say at the beginning of the game how many points each must have.[1] Cf. S. Freud Psychopathologie des Alltagsleben.Such various developments are numerous and of importance for us because we frequently are unwilling to believe the witness testifying in a certain field for the reason that his memory in another field had shown itself to be unreliable. Schubert and Drobisch cite examples of this sort of thing, but the observations of moderns, like Charcot and Binet, concerning certain lightning calculators (Inaudi, Diamandi, etc.), confirm the fact that the memory for figures is developed at the expense of other matters. Linn tells that Lapps, who otherwise note nothing whatever, are able to recognize individually each one of their numberless reindeer. Again, the Dutch friend of flowers, Voorhelm, had a memory only for tulips, but this was so great that he could recognize twelve hundred species of tulips merely from the dry bulbs.These fields seem to be of a remarkably narrow extent. Besides specialists (numismatists, zoologists, botanists, heralds, etc.) who, apart from their stupendous memory for their particular matters, appear to have no memory for other things, there are people who can remember only rhymes, melodies, shapes, forms, t.i.tles, modes, service, relationships, etc. V. Volkmar has devoted some s.p.a.ce to showing this. He has also called attention to the fact that the semi-idiotic have an astounding memory for certain things. This has been confirmed by other students. One of them, Du Potet,[1] who is perhaps the expert in the popular mind of the Austrian Alps, has made it especially clear. As in all mountainous regions there are a great number of those unfortunate idiots who, when fully developed, are called cretins, and in their milder form are semi-human, but do not possess intelligence enough to earn their own living. Nevertheless, many of them possess astounding memories for certain things. One of them is thoroughly conversant with the weather prophecy in the calendar for the past and the present year, and can cite it for each day. Another knows the day and the history of every saint of the Catholic church. Another knows the boundaries of every estate, and the name, etc., of its owner. Another knows each particular animal in a collective herd of cattle, knows to whom it belongs, etc. Of course not one of these unfortunates can read. Drobisch mentions an idiotic boy, not altogether able to speak, who, through the untiring efforts of a lady, succeeded finally in learning to read. Then after hasty reading of any piece of printed matter, he could reproduce what he had read word for word, even when the book had been one in a foreign and unknown tongue. Another author mentions a cretin who could tell exactly the birthdays and death-days of the inhabitants of his town for a decade.[1] Du Potet: Journal du Magnetisme, V. 245.It is a matter of experience that the semi-idiotic have an excellent memory and can accurately reproduce events which are really impressive or alarming, and which have left effects upon them. Many a thing which normal people have barely noticed, or which they have set aside in their memory and have forgotten, is remembered by the semi-idiotic and reproduced. On the contrary, the latter do not remember things which normal people do, and which in the latter frequently have a disturbing influence on the important point they may be considering. Thus the semi-idiotic may be able to describe important things better than normal people. As a rule, however, they disintegrate what is to be remembered too much, and offer too little to make any effective interpretation possible. If such a person, e. g., is witness of a shooting, he notices the shot only, and gives very brief attention to what precedes, what follows, or what is otherwise contemporary. Until his examination he not only knows nothing about it, but even doubts its occurrence. This is the dangerous element in his testimony. Generally it is right to believe his kind willingly. "Children and fools tell the truth," what they say bears the test, and so when they deny an event there is a tendency to overlook the fact that they have forgotten a great deal and hence to believe that the event had really not occurred.Similar experiences are yielded in the case of the memory of children. Children and animals live only in the present, because they have no historically organic ideas in mind. They react directly upon stimuli, without any disturbance of their idea of the past. This is valid, however, only for very small children. At a later age children make good witnesses, and a well-brought-up boy is the best witness in the world. We have only to keep in mind that later events tend in the child's mind to wipe out earlier ones of the same kind.[1] It used to be said that children and nations think only of the latest events. And that is universally true. Just as children abandon even their most precious toys for the sake of a new one, so they tell only the latest events in their experience. And this is especially the case when there are a great many facts- e. g., repeated mal-treatment or thefts, etc. Children will tell only of the very last, the earlier one may absolutely have disappeared from the memory.[1] F. Kemsies Gedern. Ztsch. f. pBolton,[1] who has made a systematic study of the memory of children, comes to the familiar conclusion that the scope of memory is measured by the child's capacity of concentrating its attention. Memory and acute intelligence are not always cognate (the latter proposition, true not for children alone, was known to Aristotle). As a rule girls have better memory than boys (it might also be said that their intelligence is generally greater, so long as no continuous intellectual work, and especially the creation of one's own ideas, is required). Of figures read only once, children will retain a maximum of six. (Adults, as a rule, also retain no more.) The time of forgetting in general has been excellently schematized by Ebbinghaus. He studied the forgetting of a series of thirteen nonsense syllables, previously learned, in such a way as to be able to measure the time necessary to re-learn what was forgotten. At the end of an hour he needed half the original time, at the end of eight hours two-thirds of that time. Then the process of loss became slower. At the end of twenty-four hours he required a third, at the end of six days a fourth, at the end of a month a clear fifth, of the time required at first.[1] T E. Bolton: The Growth of Memory in School Children. Am. Jour. Psych. IV.I have tested this in a rough way on various and numerous persons, and invariably found the results to tally. Of course, the measure of time alters with the memory in question, but the relations remain identical, so that one may say approximately how much may be known of any subject at the end of a fixed time, if only one ratio is tested. To criminalists this investigation of Ebbinghaus' is especially recommended.The conditions of prehensivity of particular instances are too uncertain and individual to permit any general identifications or differentiations. There are certain approximating propositions- e. g., that it is easier to keep in mind rhymed verse than prose, and definite rows and forms than block ma.s.ses. But, on the one hand, what is here involved is only the ease of memory, not the content of memory, and on the other hand there are too many exceptions -e. g., there are many people who retain prose better than verse. Hence, it is not worth while to go further in the creation of such rules. Forty or fifty years ago, investigations looking toward them had been pursued with pleasure, and they are recorded in the journals of the time.That aged persons have, as is well known, a good memory for what is long past, and a poor one for recent occurrences is not remarkable. It is to be explained by the fact that age seems to be accompanied with a decrease of energy in the brain, so that it no longer a.s.similates influences, and the imagination becomes dark and the judgment of facts incorrect. Hence, the mistakes are those of apperception of new things,-what has already been perceived is not influenced by this loss of energy.Again, it should not rouse astonishment that so remarkable and delicately organized a function as memory should be subject to anomalies and abnormalities of all kinds. We must take it as a rule not to a.s.sume the impossibility of the extraordinary phenomena that appear and to consult the expert about them.[1] The physician will explain the pathological and pathoformic, but there is a series of memory-forms which do not appear to be diseased, yet which are significantly rare and hence appear improbable. Such forms will require the examination of an experienced expert psychologist who, even when unable to explain the particular case, will still be able to throw some light on it from the literature of the subject. This literature is rich in examples of the same thing; they have been eagerly collected and scientifically studied in the earlier psychological investigations. Modern psychology, unfortunately, does not study these problems, and in any event, its task is so enormous that the practical problems of memory in the daily life must be set aside for a later time. We have to cite only a few cases handled in literature.