Chapter I: Memory (2)

_Failure of Memory accompanies failure of mental Power._--A decline of mental vigor, whether produced by disease or age, is usually attended with loss of memory to some extent. The first symptoms of this failure are usually forgetfulness of proper names and dates, and sometimes of words in general. A stroke of palsy frequently produces this result, and in such cases the name sometimes suggests the object, while the object no longer recalls the name. This is probably owing to the fact that the sign, being of less consequence than the thing signified, and making less impression on the mind, is more readily forgotten; hence the name, if suggested, recalls the thing, while, at the same time, the thing may not recall the name. In general, we pass more readily from the sign to the thing signified, than the reverse, and for the reason now given. Mr. Steward remarks, that this loss of proper names incident to old men, is chiefly observable in men of science, or those much occupied with important affairs--a fact resulting, he thinks, partly from their habits of general thought, and partly from their want of constant practice in that trivial conversation which is every moment recalling particulars to the mind.

_The Memory of the Aged._--In the principles which have been advanced, we find an explanation, I think, of some facts respecting memory, which every one has noticed, but of which the philosophy may not be at first sight apparent, Why is it that aged people forget? that, as we grow old, while perhaps other powers of the mind are still vigorous, the memory begins to lose its tenacity? Not, I suspect, from any special change which the brain undergoes, for why should such changes affect _this_ faculty more than any other? I should seek the explanation in a failure of one or other of the conditions already mentioned as essential to a good memory; either in the want of a sufficiently frequent coëxistence of associated ideas, or else in the want of a sufficiently vivid conception of them when presented; or, more likely, in both. And so the facts would indicate. Age involves usually the gradual failure and decay of the powers of perception; the ear fails to report what is said, the eye what is passing in space; and as memory is dependent on prior perception, of course a diminished activity of the one brings about a diminished activity of the other. In proportion as this ensues, the mind's interest in passing events is likely to fail, for what is no longer clearly apprehended no longer awakens the same interest and attention as formerly. This directly affects the vividness of conception, and indirectly also reacts upon the frequency of coëxistence, for what we do not clearly apprehend, nor feel much interest in, will not be likely often to recur to mind, nor shall we dwell upon it when presented. There is thus brought about, by the mutual action and reaction of the causes now specified, a failure more or less complete of the essential conditions of a retentive memory.

The old man dwells accordingly much in the _past_. His life is behind him, and not in advance. He is unobservant of passing events, because he neither clearly apprehends them, now that his connection with the outer world is in a measure interrupted by the decay of sense, nor does he much care about them, for the same reason. His attention and interest, withdrawn in a manner from these, revert to the past. Those things he remembers, the sports and companions of his youth, and the stirring events of his best and most active years, for those things _have_ been frequently associated in his mind, linked with each other, and with all the past of his life, and they _have_ deeply interested him. Hence they are remembered while yesterday is forgotten.

_Varieties of Memory._--Why is it, you ask, that memory seems to select for itself now one and now another field of operation, one man remembering dates, another events or facts in history, another words or pages of a book, while in each case the memory of other things, of every thing that lies beyond or without the favorite range of topics, is defective? Manifestly for much the same reason already given. The mind has its favorite subjects of investigation and thought; to these it frequently recurs, and dwells on them with interest; there is, consequently, frequency of coëxistence, and vividness of conception--the very conditions of retentiveness--while, at the same time, the mind being preöccupied with the given subjects, and the attention and interest withdrawn from other things, the memory of other things is proportionably deficient. We remember, in other words, just those things best, in which we are most interested, and with which we have most to do.

This explains why we forget names so readily. We have more _to do with_, and are more interested in, _persons_, than their names; the latter we have occasion to think of much less often than the former. The _sign_ occurs less frequently than the _thing signified_.

V. CULTIVATION OF MEMORY.

The principles already advanced furnish a clue to the proper and successful cultivation of the memory. Like all other powers, this may be cultivated, and to a wonderful degree; and, like all other powers, it gains strength by _use_, by exercise. The first and chief direction, then, if you would cultivate and strengthen this faculty of the mind, is, _exercise_ it; train it to do its work--to do it quickly, easily, accurately, and well--as you train yourself to handle the keys of an instrument, or to add up a column of figures with promptness and accuracy.

To be more specific.--As regards any particular thing which you wish to remember: 1. Grasp it fully, clearly, definitely in the mind; be sure you have it exactly--_it_, and not something like it or something about it. 2. Connect it with other things that are known; suffer it to link itself with other ideas and impressions already in the mind, that you may have something to recall it by. 3. Frequently revert to it, until you are sure that it has become a permanent possession, and one which you can at any time recall by any one of numerous connecting links. In this way you secure the two conditions already specified as essential, viz., frequency of coëxistence, and vividness of conception.

_Systems of artificial Memory._--A thing is recalled by the suggestion of any _coëxisting_ thought or feeling. Observing this, ingenious men have availed themselves of the principle of association to construct various mechanical or artificial systems of memory, usually termed _mnemonics_. The principle of the construction is this: should you see an elm or an oak-tree, or hear a particular tune whistled, at the same time that you were going through a demonstration in Euclid, you would be likely to think of the tree or the tune whenever next you had occasion to repeat that demonstration. The sight of the diagram would recall the associated object. They _stand together_ in your mind afterward. This we have already found to be the groundwork and chief element of all association of ideas and feelings, viz., _prior coëxistence_ in the mind. Suppose, now, you wish to fix in the mind the list of English kings. Make out a corresponding list of simple figures, or images of objects, giving each its invariable place in relation to the series: No. 1. a pump; No. 2. a goose, etc., till you reach a sufficient number, say a hundred. These are committed to memory, fixed indelibly in the mind. You then associate with those figures your English kings; Charles I. stands by the pump; Charles II. pursues the goose; James hugs the bear, and so on. These things thus once firmly linked together, remain afterward associated, and the figure serves at once to recall the associate monarch and to fix his place in the series. The same series of figures, of course, will serve for any number of different series of events, personages, etc., which are to be remembered.

_Utility questioned._--It may be seriously questioned, I think, whether such systems are of real value; whether they do not really weaken the memory and throw it into disuse, by departing from the ordinary laws and methods of suggestion, and substituting a purely artificial, arbitrary and mechanical process; whether, moreover, they really accomplish what they propose; whether, since the signs or figures have no natural relation to each other, and none to the things signified, but only the arbitrary relation imposed by the system, it is not really as difficult to fix the connection of the two things in your mind, _e. g._, to remember that Charles the Second is represented by a dog or by a goose, as it would be simply, and in the natural way, to remember the things themselves without any _such_ association.

_Extent to which the Memory may be cultivated._--The extent to which the cultivation of the memory may be carried by due training and care, is a topic worthy of some attention. Men of reflection and thought, and generally men of studious habits, literary men and authors, do not, for the most part, rely so much upon the memory as men of a more practical cast and of business pursuits; for this reason, viz., the want of due exercise, this faculty of their minds is not in the most favorable circumstances for development. Some striking exceptions, however, we shall have occasion presently to mention.

It has been already remarked, that prior to the art of printing, the cultivation of the memory was an object of far greater importance, to those who were destined for public life, than it is in modern times, and consequently instances of remarkable memory are much more frequently to be met with among the ancients than among the men of our times. The same remark will apply to men of different pursuits in any age: the more one has occasion to employ the memory, the more striking will be its development.

_Instances of extraordinary Memory._--Cyrus, it is said, knew the name of every officer, Pliny has it of every soldier, that served under him. Themistocles could call by name each one of the twenty thousand citizens of Athens. Hortensius could sit all day at an auction, and at evening give an account from memory of every thing sold, the purchaser, and the price. Muretus saw at Padua a young Corsican, says Mr. Stewart, who could repeat, without hesitation, thirty-six thousand names in the order in which he heard them, and then reverse the order and proceed backward to the first.

Dr. Wallis of Oxford, on one occasion, at night, in bed, proposed to himself a number of fifty-three places, and found its square root to twenty-seven places, and, without writing down numbers at all, dictated the result from memory twenty days afterward. It was not unusual with him to perform arithmetical operations in the dark, as the extraction of roots, _e. g._, _to_ forty _decimal_ places. The distinguished Euler, blind from early life, had always in his memory a table of the first six powers of all numbers, from one to one hundred. On one occasion two of his pupils, calculating a converging series, on reaching the seventeenth term, found their results differing by one unit at the fiftieth figure, and in order to decide which was correct, Euler went over the whole in his head, and his decision was found afterward to be correct. Pascal forgot nothing of what he had read, or heard, or seen. Menage, at seventy-seven, commemorates, in Latin verses, the favor of the gods, in restoring to him, after partial eclipse, the full powers of memory which had adorned his earlier life.

The instances now given are mentioned by Mr. Stewart but perhaps the most remarkable instance of great memory in modern times, is the case of the celebrated _Magliabechi_, librarian of the Duke of Tuscany. He would inform any one who consulted him, not only who had directly treated of any particular subject, but who had indirectly touched upon it in treating of other subjects, to the number of perhaps one hundred different authors, giving the name of the author, the name of the book, the words, often the page, where they were to be found, and with the greatest exactness. To test his memory, a gentleman of Florence lent him at one time a manuscript he had prepared for the press, and, some time afterward, went to him with a sorrowful face, and pretended to have lost his manuscript by accident. The poor author seemed inconsolable, and begged Magliabechi to recollect what he could, and write it down. He assured the unfortunate man that he would, and setting about it, wrote out the entire manuscript without missing a word. He had a _local_ memory also, knew where every book stood. One day the Grand Duke sent for him to inquire if he could procure a book which was very scarce. "No, sir," answered Magliabechi; "it is impossible: there is but _one_ in the world; that is in the Grand Seignior's library at Constantinople, and is the _seventh book, on the seventh shelf, on the right hand as you go in_."

VI. EFFECTS OF DISEASE ON THE MEMORY.

_Forgetfulness of certain Objects._--Of the effect of certain forms of disease, and also of age, in weakening the power of remembering names, I have already spoken. There are other effects, occasionally produced by disease upon this faculty of the mind, which are not so readily explained. In some cases, a certain class of objects, or the knowledge of certain persons, or of a particular language or some part of a language, as substantives, _e. g._, seems to be lost to the mind; in other cases, a certain portion of life is obliterated from the recollection. In cases of severe injury to the head, persons have forgotten some particular language; others have been unable to recall afterward the names of the most common objects, while the memory was at no loss for adjectives. A surgeon mentioned by Dr. Abercrombie, so far recovered from a fall as to give special directions respecting his own treatment, yet, for several days, lost all idea of having either a wife or children. The case of Mr. Tennent, who on recovering from apparent death, lost all knowledge of his past life, and was obliged to commence again the study of the alphabet, until after considerable time his knowledge suddenly returned to him, is too well known to require minute description.

_Former Objects recalled._--In other instances, precisely the reverse occurs. Disease brings back to mind what has been long forgotten. Thus, persons in extreme sickness, or at the point of death, not unfrequently converse in languages which they have known only in youth. The case cited by Coleridge, and so frequently quoted, of the German servant girl, who in sickness was heard repeating passages of Greek, Latin, and Hebrew, which she had formerly heard her master repeat, as he walked in his study, but of whose meaning she had no idea, is in point in this connection. So also is the case of the Italian mentioned by Dr. Rush, who died in New York, and who, in the beginning of his sickness, spoke English, in the middle of it, French, but on the day of his death, nothing but Italian. A Lutheran clergyman of Philadelphia told Dr. Rush that it was not uncommon for the Germans and Swedes of his congregation, when near death, to speak and pray in their native languages, which some of them had probably not spoken for fifty years. These facts are sufficiently numerous to constitute a class by themselves; they seem to fall under some law of the physical system not yet clearly understood, and are, therefore, in the present state of our knowledge, incapable of explanation.

_Inference often drawn from these Facts._--Certain writers have inferred, from the recurrence of things long forgotten, as in the cases now cited, that all knowledge is indestructible and that all which is necessary to the entire reproduction of the past life is the quickened activity of the mental powers an effect which is produced in the delirium of disease. From this they have derived an argument for future retribution Coleridge has made such use of it, and has been followed by Upham, and in part, at least, though with more caution, by Wayland.

_The true Inference._--It may be doubted, perhaps, whether the absolute indestructibility of all human knowledge is a legitimate inference from these facts. The most that can with certainty be concluded from them, is, not that all our past thoughts and consciousness _must_ or _will_ return, but that much of it _may_--perhaps all of it; and this is all we need to know in order to perceive the _possibility_ of a future retribution. It is enough to know, that in the constitution of the mind _means exist_ for recalling, in some way to us mysterious, and under certain conditions not by us fully understood, the objects of our former consciousness, in all the freshness and vividness of their past cognizance, long after they seem to have passed finally from the memory.

_Importance of a well-spent Life._--This simple fact, together with the well-known tendency of the mind in advancing age to revert to the scenes and incidents of early life, certainly presents in the clearest light the importance of a well-spent life, of a mind stored with such recollections as shall cast a cheerful radiance over the past, and brighten the uncertain future in those hours of gloom and despondency when the shadows lengthen upon the path of earthly pilgrimage, and life is drawing to a close. If the thoughts and impressions of the passing moment are liable, by some casual association, by some mysterious law of our being, under conditions which may at any moment be fulfilled, to recur at any time to subsequent consciousness, with all the minuteness and power of present reality, it becomes us, as we regard our own highest interests, to guard well the avenues of thought and feeling against the first approach of that which we shall not be pleased to meet again, when it will not be in our power to escape its _presence_, or avoid its recognition.

VII. INFLUENCE OF MEMORY ON THE HAPPINESS OF LIFE.

_The Pleasures of the Past thus retained._--Of the importance of this faculty as related to other intellectual powers, I have already spoken. I refer now to its value as connected with human happiness, as the source of some of the purest pleasures of life. The present, however joyous, is fleeting and evanescent. Memory seizes the passing moment, fixes it upon the canvas, and hangs the picture on the soul's inner chambers for her to look upon when she will. Thus, in an important sense, the former years are past, but not gone. We live them over again in memory.

_Instance of Niebuhr._--It is related of Carsten Niebuhr, the Oriental traveller, that "when old and blind, and so feeble that he had barely strength to be borne from his bed to his chair, the dim remembrance of his early adventures thronged before his memory with such vividness that they presented themselves as pictures upon his sightless eye-balls. As he lay upon his bed, pictures of the gorgeous Orient flashed upon his darkness as distinctly as though he had just closed his eyes to shut them out for an instant. The cloudless blue of the eastern heavens bending by day over the broad deserts, and studded by night with southern constellations, shone as vividly before him, after the lapse of half a century, as they did upon the first Chaldean shepherds whom they won to the worship of the host of heaven; and he discoursed with strange and thrilling eloquence upon those scenes which thus, in the hours of stillness and darkness, were reflected upon his inmost soul."

_The same Thing occurs often in old Age._--Something of this kind not unfrequently occurs in advanced life. Picture to yourself an old man of many winters. The world in which his young life began has grown old with him and around him, and its brightest colors have faded from his vision. The life and stir, the whirl and tumult of the busy world, the world of to-day and yesterday, move him not. He heeds but slightly the events of the passing hour. He lives in a past world. The scenes of his childhood, the sports and companions of his youth, the hills and streams, the bright eyes and laughing faces on which his young eyes rested, in which his young heart delighted--these visit him again in his solitude, as he sits in his chair by the quiet fireside. He lives over again the past. He wanders again by the old hills, and over the old meadows. He feels again the vigor of youth. He leads again his bride to the altar. He brings home toys for his children, and enters again into their sports. And so the extremes of life meet. Age completes the circuit, and brings us back to the starting-point. We close where we began. Life is a magic ring.

_The recollection of past Sorrow not always painful._--But life is not all joyous. Mingled with the brighter hues of every life are also much sadness and sorrow, and these, too, are to be remembered. It might be supposed that, while memory, by recalling the pleasing incidents of the past, might contribute much to our happiness, she would add, in perhaps an equal degree, to our sorrow, by recalling much that is painful to the thoughts. Such, however, I am convinced, is not the fact. The benevolence of the Creator has ordered it otherwise. To no one, perhaps, is memory the source of greater pleasure, strange as it may seem, than to the mourner. The very circumstances that tend to renew our grief, and keep alive our sorrow, in case of some severe calamity or bereavement, are still cherished with a melancholy satisfaction of which we would not be deprived. There is a luxury in our very grief, and in the remembrance of that for which we grieve. We would not forget what we have lost. Every recollection and association connected with it are sacred. Time assuages our grief, but impairs not the strength and sacredness of those associations, nor diminishes the pleasure with which we recall the forms we shall see no more, and the scenes that are gone forever. Every memento of the departed one is sacred; the books, the flowers, the favorite walks, the tree in whose shadow he was wont to recline, all have a significance and a value which the stricken heart only can interpret, and which memory only can afford.

_We recollect the Past as it was._--It is to be noticed, also, that, in such cases, the picture which memory furnishes is a transcript of the past as it was; the image is stereotyped and unchangeable. Other things change, we change; that changes not. It has a fixed value. A mother, for instance, loses a child of three years. It ever remains to her a child of three years. She remembers it as it was. She grows old; twenty summers and winters pass; yet as often as she visits the little mound, now scarce to be distinguished from the level surface, there comes to her recollection that little child as he was, when she hung, for the last time, over that pale, sweet face that she should see no more. She still thinks of him, dreams of him, as a child, for it is as such only that she remembers him.

Blessed boon, that gives us just the past; when all things change, fortunes vary, friends depart, the world grows unkind, and we grow old, the former things remain treasured in our memory, and we can stand as mourners at the grave of what we once were.

VIII. HISTORICAL SKETCH.--DIFFERENT THEORIES OF MEMORY.

_Ancient Theory._--The idea formerly, and almost universally entertained respecting the _modus operandi_ of the faculty we call memory, was, that in perception and the various operations of the senses, certain impressions are made on the sensorium--certain forms and types of things without, certain _images_ of them--which remain when the external object is no longer present, and become imprinted thus on the mind. Such, certainly, was the doctrine of the earliest Greek commentators on Aristotle. Such, I must think, is substantially the doctrine of Aristotle himself.

_Theory of Aristotle._--His idea is, that memory, as well as imagination, primarily and directly, relates only to sensible objects, and gives us only _images_ of these objects, and even when it gives us strictly intellectual objects, gives us these only by images. One cannot _think_, he says, without images. Its source and origin, then, he concludes, is the sensibility, and so it pertains to _animals_, as well as men; only to those, however, which have the perception of time, since memory is a modification of sensation or intellectual conception, under the condition of _time past_. Such being, in his view, the nature and source of memory, he goes on to ask how it is that only a modification (or state) of the mind being present, and the object itself absent, one recalls that absent object?

"Manifestly," he replies, "we must believe that the impression which is produced, in consequence of the sensation, in the soul, and in that part of the body which perceives the sensation, is analogous to a species of painting, and that the perception of that impression constitutes precisely what we call memory. The movement which then takes place in the mind _imprints there a sort of type of the sensation_ analogous to the _seal which one imprints on wax with a ring_. Hence it is that those who by the violence of the impression, or by the ardor of age are in a great excitement (movement) have not the memory of things, as if the movement and seal had been applied to running water. In the case of others, however, who are in a sort cold, as the plaster of old edifices, the very _hardness_ of the part which receives the impression prevents the image from leaving the least trace. Hence it is that young children and old men have so little memory. It is the same with those who are too lively, and those who are too slow. Neither remember well. The one class are too _humid_, the other too hard. The image dwells not in the soul of the one, makes no impression whatever on that of the other.

"How is it now," he goes on to ask, "that this stamp, impression, image, or painting, in us, a mere mode of the mind, can recall the absent object?" His answer is, that the impression or image is a _copy_ of that object, while, at the same time, it is, in itself considered, only a modification of our mind, just as a painting is a mere picture, and yet a _copy_ from nature. (Parva Naturalia: Memory, ch. 1.)

_Defence of Aristotle._--Sir W. Hamilton defends Aristotle against the strictures of Dr. Reid, upon this subject, by the supposition that he used these expressions not in a literal, but in a figurative or analogical sense. The figure, however, if it be one, is very clearly and boldly sustained, and constitutes, in fact, the whole explanation given of the process of memory--the entire theory. Take away these expressions, and you take away the whole substance of his argument, the whole solution of the problem. Sensation, or intellectual conception, produces an _impression_ on the soul, and _imprints there a type_ of itself, not unlike a painting or the stamp of a seal on wax, and the _perception_ of this is _memory_. Such is in brief his theory.

_Theory of Hobbes._--Not far remote from this was the theory of Hobbes, who regarded memory as a decaying or vanishing sense; that of Hume, who represents it as merely a somewhat weaker impression than that which we designate as perception; and that of the celebrated Malebranche, who accounted for memory by making it to depend entirely on the changes which take place in the fibres of the brain. "For even as the branches of a tree which have continued some time bent in a certain form, still preserve an aptitude to be bent anew after the same manner, so the fibres of the brain having once received certain impressions by the course of the animal spirits, and by the action of objects, retain a long time some facility to receive these same dispositions. Now the memory consists only in this faculty, since we think on the same things when the brain receives the same impressions."

He goes on to explain how, as the brain undergoes a change in different periods of life, the mind is affected accordingly. "The fibres of the brain in children are soft, flexible, and delicate; a riper age dries, hardens, and strengthens them; but in old age they become wholly inflexible." ... "For as we see the fibres which compose the flesh harden by time, and that the flesh of a young partridge is, without dispute, more tender than that of an old one, so the fibres of the brain of a child or youth will be much more soft and delicate than those of persons more advanced in years."

_Strictures upon this Theory._--Without disputing what is here stated as to the difference in the fibres of the brain at different periods of life, it remains to be proved that all this has any thing to do with the differences of memory in different persons, or with the phenomena of memory in general.

These theories, it will be observed, all assume that in perception and sensation some physical effect is produced on the system, which remains after the original sensation or perception has ceased to act, and that memory is the _result_ of that remaining effect, the perception, or conscious cognizance of it by the mind. The process is a purely physiological one. Without insisting on the expressions made use of to represent this process, all which convey the idea strongly of a mechanical effect--type imprinted on the soul, impression made on it as of a seal on wax, image, picture, copy, etc.; allowing these to be mere metaphors; allowing, moreover, that the essential fact all along assumed, is a fact, viz., that in sensation, perception, etc., some physical effect is produced on the sensorium; there are still two essential propositions to be established before we can admit any of these theories: 1. That this physical effect _remains_ any time after the cause ceases to operate; 2. That if so, it is in any way concerned in the production of memory; and even if these points could be made out, it would still be an open question, in WHAT way, possible or conceivable, this effect or impression on the sensorium gives rise to the phenomenon of memory; for this is, after all, the chief thing to be explained.