Memory: A Contribution to Experimental
Psychology
Hermann Ebbinghaus (1885)
Translated by Henry A. Ruger & Clara E. Bussenius (1913)
CHAPTER I
OUR KNOWLEDGE CONCERNING MEMORY
Section 1. Memory in its Effects
The language of life as well as of science in attributing a memory
to the mind attempts to point out the facts and their interpretation
somewhat as follows:
Mental states of every kind, -- sensations, feelings, ideas, --
which were at one time present in consciousness and then have
disappeared from it, have not with their disappearance absolutely
ceased to exist. Although the inwardly-turned look may no longer be
able to find them, nevertheless they have not been utterly destroyed
and annulled, but in a certain manner they continue to exist, stored
up, so to speak, in the memory. We cannot, of course, directly observe
their present existence, but it is revealed by the effects which come
to our knowledge with a certainty like that with which we infer the
existence of the stars below the horizon. These effects are of
different kinds.
In a first group of cases we can call back into consciousness by an
exertion of the will directed to this purpose the seemingly lost
states (or, indeed, in case these consisted in immediate
sense-perceptions, we can recall their true memory images) that is, we
can reproduce them voluntarily. During attempts of this sort,
-- that is, attempts to recollect -- all sorts of images toward which
our aim was not directed, accompany the desired images to the light of
consciousness. Often, indeed, the latter entirely miss the goal, but
as a general thing among the representations is found the one which we
sought, and it is immediately recognised as something formerly
experienced. It wou1d be absurd to suppose that our will has created
it anew and, as it were, out of nothing; it must have been present
somehow or somewhere. The will, so to
speak, has only discovered it and brought it to us again.
In a second group of cases this survival is even more striking.
Often, even after years, mental states once present in consciousness
return to it with apparent spontaneity and without any act of the
will; that is, they are reproduced involuntarily. Here, also,
in the majority of cases we at once recognise the returned mental
state as one that has already been experienced; that is, we remember
it. Under certain conditions, however, this accompanying consciousness
is lacking, and we know only indirectly that the "now" must
be identical with the "then"; yet we receive in this way a
no less valid proof for its existence during the intervening time. As
more exact observation teaches us, the occurrence of these involuntary
reproductions is not an entirely random and accidental one. On the
contrary they are brought about through the instrumentality of other
immediately present mental images. Moreover they occur in certain
regular ways which in general terms are described under the so-called
'laws of association.'
Finally there is a third and large group to be reckoned with here.
The vanished mental states give indubitable proof of their continuing
existence even if they themselves do not return to consciousness at
all, or at least not exactly at the given time. Employment of a
certain range of thought facilitates under certain conditions the
employment of a similar range of thought, even if the former does not
come before the mind directly either in its methods or in its results.
The boundless domain of the effect of accumulated experience belongs
here. This effect results from the frequent conscious occurrence of
any condition or process, and consists in facilitating the occurrence
and progress of similar processes. This effect is not fettered by the
condition that the factors constituting the experience shall return in
toto to consciousness. This may incidentally be the case with a
part of them; it must not happen to a too great extent and with too
great clearness, otherwise the course of the present process will
immediately be disturbed. Most of these experiences remain concealed
from consciousness and yet produce an effect which is significant and
which authenticates their previous existence.
Section 2. Memory in its Dependence
Along with this bare knowledge of the existence of memory and its effects,
there is abundant knowledge concerning the conditions upon
which depend the vitality of that inner survival as well as the
fidelity and promptness of the reproduction.
How differently do different individuals behave in this
respect! One retains and reproduces well; another, poorly. And not
only does this comparison hold good when different individuals are
compared with each other, but also when different phases of the
existence of the same individual are compared: morning and evening,
youth and old age, find him different in this respect.
Differences in the content of the thing to be reproduced are
of great influence. Melodies may become a source of torment by the
undesired persistency of their return. Forms and colors are not so
importunate; and if they do return, it is with noticeable loss of
clearness and certainty. The musician writes for the orchestra what
his inner voice sings to him; the painter rarely relies without
disadvantage solely upon the images which his inner eye presents to
him; nature gives him his forms, study governs his combinations of
them. It is with something of a struggle that past states of feeling
are realized; when realized, and this is often only through the
instrumentality of the movements which accompanied them, they are but
pale shadows of themselves. Emotionally true singing is rarer than
technically correct singing.
If the two foregoing points of view are taken together --
differences in individuals and differences in content -- an endless
number of differences come to light. One individual overflows with
poetical reminiscences, another directs symphonies from memory, while
numbers and formulae, which come to a third without effort, slip away
from the other two as from a polished stone.
Very great is the dependence of retention and reproduction upon the
intensity of the attention and interest which were
attached to the mental states the first time they were present. The
burnt child shuns the fire, and the dog which has been beaten runs
from the whip, after a single vivid experience. People in whom we are
interested we may see daily and yet not be able to recall the color of
their hair or of their eyes.
Under ordinary circumstances, indeed, frequent repetitions are
indispensable in order to make possible the reproduction of a given
content. Vocabularies, discourses, and poems of any length cannot be
learned by a single repetition even with the greatest concentration of
attention on the part of an individual of very great ability. By a
sufficient number of repetitions their final mastery is ensured, and
by additional later reproductions gain in assurance and ease is
secured.
Left to itself every mental content gradually loses its capacity
for being revived, or at least suffers loss in this regard under the
influence of time. Facts crammed at examination time soon vanish, if
they were not sufficiently grounded by other study and later subjected
to a sufficient review. But even a thing so early and deeply founded
as one's mother tongue is noticeably impaired if not used for several
years.
Section 3. Deficiencies in our Knowledge concerning
Memory
The foregoing sketch of our knowledge concerning memory makes no
claim to completeness. To it might be added such a series of
propositions known to psychology as the following: "He who learns
quickly also forgets quickly," "Relatively long series of
ideas are retained better than relatively short ones," Old people
forget most quickly the things they learned last," and the like.
Psychology is wont to make the picture rich with anecdote and
illustration. But -- and this is the main point -- even if we
particularise our knowledge by a most extended use of illustrative
material, everything that we can say retains the indefinite, general,
and comparative character of the propositions quoted above. Our
information comes almost exclusively from the observation of extreme
and especially striking cases. We are able to describe these quite
correctly in a general way and in vague expressions of more or less.
We suppose, again quite correctly, that the same influences exert
themselves, although in a less degree, in the case of the
inconspicuous, but a thousand-fold more frequent, daily activities of
memory. But if our curiosity carries us further and we crave more
specific and dependencies, both those already mentioned and others, --
if we put questions, so to speak, concerning their inner structure --
our answer is silence. How does the disappearance of the ability to
reproduce, forgetfulness, depend upon the length of time during which
no repetitions have taken place? What proportion does the increase in
certainty of reproduction bear to the number of repetitions? How do
these relations vary with the greater or less intensity of the
interest in the thing to be reproduced? These and similar questions no
one can answer.
This inability does not arise from a chance neglect of
investigation of these relations. We cannot say that tomorrow, or
whenever we wish to take time, we can investigate these problems. On
the contrary this inability is inherent in the nature of the questions
themselves. Although the conceptions in question -- namely, degrees of
forgetfulness, of certainty and interest -- are quite correct, we have
no means for establishing such degrees in our experience except at the
extremes, and even then we cannot accurately limit those extremes. We
feel therefore that we are not at all in a condition to undertake the
investigation. We form certain conceptions during striking
experiences, but we cannot find any realisation of them in the similar
but less striking experiences of everyday life. Vice versa there
are probably many conceptions which we have not as yet formed which
would be serviceable and indispensable for a clear understanding of
the facts, and their theoretical mastery.
The amount of detailed information which an individual has at his
command and his theoretical elaborations of the same are mutually
dependent; they grow in and through each other. It is because of the
indefinite and little specialised character of our knowledge that the
theories concerning the processes of memory, reproduction, and
association have been up to the present time of so little value for a
proper comprehension of those processes. For example, to express our
ideas concerning their physical basis we use different
metaphors-stored up ideas, engraved images, well-beaten paths. There
is only one thing certain about these figures of speech and that is
that they are not suitable.
Of course the existence of all these deficiencies has its perfectly
sufficient basis in the extraordinary difficulty and complexity of the
matter. It remains to be proved whether, in spite of the clearest
insight into the inadequacy of our knowledge, we shall ever make any
actual progress. Perhaps we shall always have to be resigned to this.
But a somewhat greater accessibility than has so far been realised in
this field cannot be denied to it, as I hope to prove presently. If by
any chance a way to a deeper penetration into this matter should
present itself, surely, considering the significance of memory for all
mental phenomena, it should be our wish to enter that path at once.
For at the very worst we should prefer to see resignation arise from
the failure of earnest investigations rather than from persistent,
helpless astonishment in the face of their difficulties.