The objects that are put away for safe-keeping differ in one respect from those things which are stored away in the memory. The material object is the same, whether we visit and inspect it from day to day or not. The banker's dollars are not increased in fineness or value by his handling them over carefully every day. Not so with intellectual coin. The more frequently we re-examine our knowledge and pass it under review, the more does it become fixed in its character, the more full and exact in its proportions. Handling it does not wear it out. Even giving it away does not diminish it. In short, so far as the cultivation of the memory is concerned, the next best thing we can do, after reducing our knowledge to due order, is to give it a frequent and thorough re-examination. Constant, almost endless repetition is the inexorable price of sound mental accumulation.
A distinction is to be made between memory as a power of the mind and the remembrance of particular facts. One or two examples will illustrate this difference. The late Dr. Addison Alexander, of the Theological Seminary at Princeton, had memory as an intellectual power to a degree almost marvellous. The following instance may be cited. On one occasion, a large class of forty or fifty were to be matriculated in the Seminary in the presence of the Faculty. The ceremony of matriculation was very simple. The professors and the new students being all assembled, in a large hall, each student in turn presented himself before the professors, had his credentials examined by them, and if the same proved satisfactory, entered his name in full and his residence, in the register. When the matriculation was complete and the students had retired, there was some bantering among the professors as to which of them should take the register home and prepare from it an alphabetical roll,—a work always considered rather tedious and irksome. After a little hesitation, Dr. Alexander said, "There is no need of taking the register home; I will make the roll for you;" and, taking a sheet of paper, at once, from memory, without referring to the register, and merely from having heard the names as they were recorded, he proceeded to make out the roll, giving the names in full and giving them in their alphabetical order. This was a prodigious feat of pure memory; for in order to make the alphabetical arrangement in his mind, before committing it to paper, he must have had the entire mass of names present in his mind by a single act of the will. Some of the wonderful games of chess performed by Paul Morphy are dependent in part upon a similar power of memory, by which the player is enabled to keep present in his mind, without seeing the board, a long series of complicated evolutions, past as well as prospective and possible. The same is true of every great military strategist.
In all these cases, there is an act of pure memory, a direct and positive power of summoning into the mind its past experiences, such as can only take place where, either by natural gift or by special training, the memory as a faculty of the mind is in a high state of vigor. But there are other cases, in which a man is enabled to recall a great number of particular facts by a species of artifice or trick, which does not imply any special mental power, and the study of which does not tend, in any marked degree, to develop such power. More than thirty years ago, the late Professor Dod, of Princeton College, in lecturing to a class on the subject of light, was explaining the solar spectrum, and after exhibiting the solar ray, divided into its seven primary colors, violet, indigo, blue, green, yellow, orange, and red, said, "If you will form a mnemonic word of the first letters of each of these words, you will be able, without further effort, to remember the order of the prismatic colors the rest of your lives," and he accordingly wrote upon the board and pronounced the uncouth and almost unpronounceable word, Vibgyor, which probably not one of us has ever forgotten. An ingenious Frenchman some years ago traversed the country and collected large audiences by his exhibitions of skill in this species of artifice, and by undertaking to initiate his hearers in the method of remembering prodigious numbers of historical facts by means of such artificial contrivances. Mnemotechny, the name which he gave to his invention, is merely a trick of the memory. It is a means of remembering a particular set of facts or things by the aid of contrivances purely artificial and arbitrary. Its possession does not imply, and its cultivation does not produce, real mnemonic power. It undoubtedly has its uses. But it is rather wealth gained by a lottery ticket than a wealth-producing power acquired by wise habits of business.
In teaching the young, it is well not to neglect either of these principles. We should give our children from time to time ingenious and interesting contrivances for remembering important facts. These contrivances, if judicious in plan and execution, will be great helps to them. We may in this way bridge over the difficulty of remembering many of the important facts and dates in history.
I would not discourage these artificial methods. Though they are mere tricks, they are valuable. But they have by no means the same value as those methods of teaching which cultivate and produce true mnemonic power. This power, like every other mental power, is given in unequal measure to different individuals. Like every other mental power, also, it grows mainly by exercise. No power of the mind is more capable of development. I have mentioned some things which tend to the growth of this power, such as presenting knowledge to children in logical and orderly arrangement, and frequent re-examination of knowledge already obtained. Perhaps there is no quickener and invigorator of the memory equal to that of reciting to a judicious teacher before a large class of fellow-students. By a proper and skilful use of the art of questioning, under the excitement of answering before a large class, the mnemonic power is subjected to a healthy and invigorating test, and all such exercises promote powerfully the mental growth. A child may absorb knowledge by mere solitary reading and study, just as a sponge absorbs water, but the knowledge so acquired readily evaporates, or is squeezed out. Something is needed to fix in the mind the knowledge that has been lodged there, and no process is more effectual to this end than that of class recitation. It is by telling other people what we have learned, that we learn it more effectually, and make it more completely our own. A good teacher, by good methods of recitation, can do more than all other persons and all other things to secure a sound and healthy growth of memory in the young.
Another thing highly necessary in cultivating a really good memory, is attaining the utmost possible clearness in our ideas. If the knowledge, when it first comes into the mind, is clearly and sharply defined, so that we really know a thing, instead of having vague and confused notions about it, we shall be the more likely to remember it permanently. Nothing is more conducive towards giving these sharp and definite impressions than the use of visible illustrations. Actual exhibition before a class of the objects talked about, actual experiments of the operations described, and the constant use of the chalk and the blackboard, presenting even abstract truths in concrete and visible symbols, as is done in algebra, chemistry, and logic, are among the means by which, chiefly, knowledge becomes well defined to the mind. Such is the constitution of the mind, that we have a clearer apprehension of what we see than of what comes to us through any other sense, and the knowledge which comes to us by means of the sight, is, of all kinds of knowledge, the most lasting and the most easily recalled. Hence, in teaching, it is hardly possible to exaggerate the importance of visible illustration.
Another condition extremely favorable to the growth of memory, is the existence of a considerable degree of mental excitement at the time that knowledge enters the mind. Metals weld easily only at a white heat. If we would obtain a vigorous grasp of knowledge, and incorporate it thoroughly into our other mental products, so that it shall become really ours, there should be the glow of mental heat at the time of our acquiring such knowledge. Ideas that come into the mind when we are in an apathetic state, make no permanent lodgment. Hence the importance of exciting a lively interest in that which is the subject of study. If the teacher has failed to excite this interest, and finds in his class no animation, no sympathy, no eagerness of attention, he may be sure that he is not accomplishing much. The child must, if possible, acquire a fondness for that which is to be remembered. Love, in fact, is the parent of memory.
VIII.
KNOWLEDGE BEFORE MEMORY.
I have had frequent occasion to urge upon teachers the importance of cultivating the memory of their pupils. The old-fashioned plan of requiring the young to commit to memory precious truths, in those very words in which wise and far-thinking men have handed them down to us, has too much gone out of use. I have felt called upon, therefore, from time to time, to recall to the minds of teachers the unspeakable importance of early exercising the memory of children, and of storing their memories with wise sayings and rules. I would not take back anything I have said on this subject, but rather repeat and reiterate it. At the same time, I am aware that there is an extreme in this direction, and I therefore put in a word of caution.