CHAPTER XVIII.

MEMORY.

Analysis of the Phenomenon of Memory.-Memory proper, or secondary memory as it might be styled, is the knowledge of a former state of mind after it has already once dropped from consciousness; or rather it is the knowledge of an event, or fact, of which meantime we have not been thinking, with the additional consciousness that we have thought or experienced it before.

The first element which such a knowledge involves would seem to be the revival in the mind of an image or copy of the original event. And it is an assumption made by many writers that such revival of an image is all that is needed to constitute the memory of the original occurrence. But such a revival is obviously not a memory, whatever else it may be; it is simply a duplicate, a second event, having absolutely no connection with the first event except that it happens to resemble it. The clock strikes to-day; it struck yesterday; and may strike a million times ere it wears out. The rain pours through the gutter this week; it did so last week; and will do so in sæcula sæculorum. But does the present clock-stroke become aware of the past ones, or the present stream recollect the past stream, because they repeat and resemble them? Assuredly not. And let it not be said that this is because clock-strokes and gutters are physical and not psychical objects; for psychical objects (sensations, for example) simply recurring in successive editions will remember each other on that account no more than clock-strokes do. No memory is involved in the mere fact of recurrence. The successive editions of a feeling are so many independent events, each snug in its

own skin. Yesterday's feeling is dead and buried; and the presence of to-day's is no reason why it should resuscitate along with to-day's. A farther condition is required before the present image can be held to stand for a past original.

That condition is that the fact imaged be expressly referred to the past, thought as in the past. But how can we think a thing as in the past, except by thinking of the past together with the thing, and of the relation of the two? And how can we think of the past? In the chapter on Time-perception we have seen that our intuitive or inimediate consciousness of pastness hardly carries us more than a few seconds backward of the present instant of time. Remoter dates are conceived, not perceived; known symbolically by names, such as 'last week,' '1850'; or thought of by events which happened in them, as the year in which we attended such a school, or met with such a loss. So that if we wish to think of a particular past epoch, we must think of a name or other symbol, or else of certain concrete events, associated therewithal. Both must be thought of, to think the past epoch adequately. And to refer any special fact to the past epoch is to think that fact with the names and events which characterize its date, to think it, in short, with a lot of contiguous associates.

But even this would not be memory. Memory requires more than mere dating of a fact in the past. It must be dated in my past. In other words, I must think that I directly experienced its occurrence. It must have that 'warmth and intimacy' which were so often spoken of in the chapter on the Self, as characterizing all experiences 'appropriated' by the thinker as his own.

A general feeling of the past direction in time, then, a particular date conceived as lying along that direction, and defined by its name or phenomenal contents, an event imagined as located therein, and owned as part of my experi ence, such are the elements of every object of memory.

Retention and Recall.-Such being the phenomenon of memory, or the analysis of its object, can we see how it comes to pass? can we lay bare its causes?

Its complete exercise presupposes two things:

1) The retention of the remembered fact; and

2) Its reminiscence, recollection, reproduction, or recall. Now the cause both of retention and of recollection is the law of habit in the nervous system, working as it does in the association of ideas.'

Association explains Recall.-Associationists have long explained recollection by association. James Mill gives an account of it which I am unable to improve upon, unless it might be by translating his word 'idea' into 'thing thought of,' or 'object.'

"There is," he says, 66 a state of mind familiar to all men,

in which we are said to remember. In this state it is certain we have not in the mind the idea which we are trying to have in it. How is it, then, that we proceed, in the course of our endeavor, to procure its introduction into the mind? If we have not the idea itself, we have certain ideas connected with it. We run over those ideas, one after another, in hopes that some one of them will suggest the idea we are in quest of; and if any one of them does, it is always one so connected with it as to call it up in the way of association. I meet an old acquaintance, whose name I do not remember, and wish to recollect. I run over a number of names, in hopes that some of them may be associated with the idea of the individual. I think of all the circumstances in which I have seen him engaged; the time when I knew him, the persons along with whom I knew him, the things he did, or the things he suffered; and if I chance upon any idea with which the name is associated, then immediately I have the recollection; if not, my pursuit of it is vain. There is another set of cases, very familiar, but affording very important evidence on the subject. It frequently happens that there are matters which we desire not to forget. What is the contriv

ance to which we have recourse for preserving the memory —that is, for making sure that it will be called into existence when it is our wish that it should? All men invariably employ the same expedient. They endeavor to form an association between the idea of the thing to be remembered and some sensation, or some idea, which they know beforehand will occur at or near the time when they wish the remembrance to be in their minds. If this association is formed and the association or idea with which it has been formed occurs, the sensation, or idea, calls up the remembrance, and the object of him who formed the association is attained. To use a vulgar instance: a man receives a commission from his friend, and, that he may not forget it, ties a knot in his handkerchief. How is this fact to be explained? First of all, the idea of the commission is associated with the making of the knot. Next, the handkerchief is a thing which it is known beforehand will be frequently seen, and of course at no great distance of time from the occasion on which the memory is desired. The handkerchief being seen, the knot is seen, and this sensation recalls the idea of the commission, between which and itself the association had been purposely formed."

In short, we make search in our memory for a forgotten idea, just as we rummage our house for a lost object. In both cases we visit what seems to us the probable neighborhood of that which we miss. We turn over the things under which, or within which, or alongside of which, it may possibly be; and if it lies near them, it soon comes to view. But these matters, in the case of a mental object sought, are nothing but its associates. The machinery of recall is thus the same as the machinery of association, and the machinery of association, as we know, is nothing but the elementary law of habit in the nerve-centres.

It also explains retention. And this same law of habit is the machinery of retention also. Retention means liability to recall, and it means nothing more than such liability. The only proof of there being retention is that

recall actually takes place. The retention of an experience is, in short, but another name for the possibility of thinking it again, or the tendency to think it again, with its past surroundings. Whatever accidental cue may turn this tendency into an actuality, the permanent ground of the tendency itself lies in the organized neural paths by which the cue calls up the memorable experience, the past associates, the sense that the self was there, the belief that it all really happened, etc., as previously described. When the recollection is of the 'ready' sort, the resuscitation takes place the instant the cue arises; when it is slow, resuscitation comes after delay. But be the recall prompt or slow, the condition which makes it possible at all (or, in other words, the 'retention of the experience) is neither more nor less than the brain-paths which associate the experience with the occasion and cue of the recall. When slumbering, these paths are the condition of retention; when active, they are the condition of recall.

Brain-scheme. A simple scheme will now make the whole cause of memory plain. Let n be a past event, o its setting' (concomitants, date,

N

M

self present, warmth and intimacy, etc., etc., as already set forth), and m some present thought or fact which may appropriately become the occasion of its recall. Let the nerve-centres, active in the thought of m, n, and o, be represented by M, N, and 0, respectively; then the existence of the paths symbolized by the lines between M and N and N and O will be the fact indicated by the phrase 'retention of the event " in the memory,' and the excitement of the brain along these paths will be the condition of the event n's actual recall. The retention of n, it will be observed, is no mysterious storing up of an 'idea' in an unconscious state. It is not a fact of the mental order at all. It is a

FIG. 62,