Our ignorance concerning memory is as great as its universal importance,
and as our indebtedness to it for what we are and possess. At best we
have, when explaining it, to make use of images.
Plato accounts for memory in the “Theaetetus” by the image of the seal
ring which impresses wax; the character and duration of the impression
depends upon the size, purity, and hardness of the wax. Fichte says,
“The spirit does not conserve its products,--the single ideas,
volitions, and feelings are conserved by the mind and constitute the
ground of its inexhaustibly retentive memory.... The possibility of
recalling what has once been independently done, this remains in the
spirit.” James Sully compares the receptivity of memory with the
infusion of dampness into an old MS. Draper also brings a physical
example: If you put a flat object upon the surface of a cold, smooth
metal and then breathe on the metal and, after the moisture has
disappeared, remove the object, you may recall its image months after,
whenever you breathe on the place in question. Another has called memory
the safe of the mind. It is the opinion of E. Hering[214] that what we
once were conscious of and are conscious of again, does not endure as
image but as echo such as may be heard in a tuning fork when it is
properly struck. Reid asserts that memory does not have present ideas,
but past things for its object. Natorp explains recollection as an
identification of the unidentical, of not-now with now. According to
Herbart and his school,[215] memory consists in the possibility of
recognizing the molecular arrangements which had been left by past
impressions in the ganglion cells, and in reading them in identical
fashion. According to Wundt and his pupils, the problem is one of the
disposition of the central organs. And it is the opinion of James Mill
that the content of recollection is not only the idea of the remembered
object, but also the idea that the object had been experienced before.
Both ideas together constitute the whole of that state of mind which we
denote as memory. Spinoza[216] deals freely with memory, and asserts
that mankind does not control it inasmuch as all thoughts, ideas,
resolutions of spirits, are bare results of memories, so that human
freedom is excluded. Uphues[217] distinguishes between memory and the
conception which is presupposed in the recognition of an object
different from that conception. This is the theory developed by
Aristotle.
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[218] 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.” Külpe[219] 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 assert. He concludes that they are not
so.
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.”
Nobody has as yet paid attention to the simple daily events which
constitute 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 association 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 circumstances 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 associations 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 asserts that
some matter of importance occurred to him in the twilight. Such an
assertion merits, at least, further examination. Now, if we only know
how these occurrences constitute 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
assuming 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 asserts 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 passive 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 proportionate 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.