Freud - Complete Works (172 page)

Fig. 1.

The Interpretation Of Dreams

971

   This, however, does no more than
fulfil a requirement with which we have long been familiar, namely
that the psychical apparatus must be constructed like a reflex
apparatus. Reflex processes remain the model of every psychical
function.

   Next, we have grounds for
introducing a first differentiation at the sensory end. A trace is
left in our psychical apparatus of the perceptions which impinge
upon it. This we may describe as a ‘memory-trace’; and
to the function relating to it we give the name of
‘memory.’ If we are in earnest over our plan of
attaching psychical processes to systems, memory-traces can only
consist in permanent modifications of the elements of the systems.
But, as has already been pointed out elsewhere, there are obvious
difficulties involved in supposing that one and the same system can
accurately retain modifications of its elements and yet remain
perpetually open to the reception of fresh occasions for
modification. In accordance, therefore, with the principle which
governs our experiment, we shall distribute these two functions on
to different systems. We shall suppose that a system in the very
front of the apparatus receives the perceptual stimuli but retains
no trace of them and thus has no memory, while behind it there lies
a second system which transforms the momentary excitations of the
first system into permanent traces. The schematic picture of our
psychical apparatus would then be as follows (Fig. 2):

Fig. 2.

The Interpretation Of Dreams

972

   It is a familiar fact that we
retain permanently something more than the mere
content
of
the perceptions which impinge upon the system
Pcpt
. Our
perceptions are linked with one another in our memory - first and
foremost according to simultaneity of occurrence. We speak of this
fact as ‘association.’ It is clear, then, that, if the
Pcpt
. system has no memory whatever it cannot retain any
associative traces; the separate
Pcpt
. elements would be
intolerably obstructed in performing their function if the remnant
of an earlier connection were to exercise an influence upon a fresh
perception. We must therefore assume the basis of association lies
in the mnemic systems. Association would thus consist in the fact
that, as a result of a diminution in resistances and of the laying
down of facilitating paths, an excitation is transmitted from a
given
Mnem
. element more readily to one
Mnem
. element
than to another.

   Closer consideration will show
the necessity for supposing the existence not of one but of several
such
Mnem
. elements, in which one and the same excitation,
transmitted by the
Pcpt
. elements, leaves a variety of
different permanent records. The first of these
Mnem
.
systems will naturally contain the record of association in respect
to
simultaneity in time
; while the same perceptual material
will be arranged in the later systems in respect to other kinds of
coincidence, so that one of these later systems, for instance, will
record relations of similarity, and so on with the others. It would
of course be a waste of time to try to put the psychical
significance of a system of this kind into words. Its character
would lie in the intimate details of its relations to the different
elements of the raw material of memory, that is - if we may hint at
a theory of a more radical kind - in the degrees of conductive
resistance which it offered to the passage of excitation from those
elements.

   At this point I will interpolate
a remark of a general nature which may perhaps have important
implications. It is the
Pcpt
. system, which is without the
capacity to retain modifications and is thus without memory, that
provides our consciousness with the whole multiplicity of sensory
qualities. On the other hand, our memories - not excepting those
which are most deeply stamped on our minds - are in themselves
unconscious. They can be made conscious; but there can be no doubt
that they can produce all their effects while in an unconscious
condition. What we describe as our ‘character’ is based
on the memory-traces of our impressions; and, moreover, the
impressions which have had the greatest effect on us - those of our
earliest youth - are precisely the ones which scarcely ever become
conscious. But if memories become conscious once more they exhibit
no sensory quality or a very slight one in comparison with
perceptions. A most promising light would be thrown on the
conditions governing the excitation of neurone if it could be
confirmed that
the ­
Ψ
­-systems
of memory and the quality that characterizes consciousness are
mutually exclusive
.¹

  
¹
[
Footnote added
1925:] I have since
suggested that consciousness actually arises
instead of
the
memory-trace. See my ‘Note upon the "Mystic
Writing-Pad"' (1925
a
).

The Interpretation Of Dreams

973

   The assumptions we have so far
put forward as to the construction of the psychical apparatus at
its sensory end have been made without reference to dreams or to
the psychological information that we have been able to infer from
them. Evidence afforded by dreams will, however, help us towards
understanding another portion of the apparatus. We have seen that
we were only able to explain the formation of dreams by venturing
upon the hypothesis of there being two psychical agencies, one of
which submitted the activity of the other to a criticism which
involved its exclusion from consciousness. The critical agency, we
concluded, stands in a closer relation to consciousness than the
agency criticized: it stands like a screen between the latter and
consciousness. Further we found reasons for identifying the
critical agency with the agency which directs our waking life and
determines our voluntary, conscious actions. If, in accordance with
our assumptions, we replace these agencies by systems, then our
last conclusion must lead us to locate the critical system at the
motor end of the apparatus. We will now introduce the two system
into our schematic picture and give them names to express their
relation to consciousness (Fig. 3):

Fig. 3.

The Interpretation Of Dreams

974

   We will describe the last of the
systems at the motor end as ‘the preconscious’, to
indicate that the excitatory processes occurring in it can enter
consciousness without further impediment provided that certain
other conditions are fulfilled: for instance, that they reach a
certain degree of intensity, that the function which can only be
described as ‘attention’ is distributed in a particular
way, and so on. This is at the same time the system which holds the
key to voluntary movement. We will describe the system that lies
behind it as ‘the unconscious’, because it has no
access to consciousness
except via the preconscious
, in
passing through which its excitatory process is obliged to submit
to modifications.¹

   In which of these systems, then,
are we to locate the impetus to the construction of dreams? For
simplicity’s sake, in the system
Ucs
. It is true that
in the course of our future discussion we shall learn that this is
not entirely accurate, and that the process of forming dreams is
obliged to attach itself to dream-thoughts belonging to the
preconscious system. But when we consider the dream-wish, we shall
find that the motive force for producing dreams is supplied by the
Ucs
.; and owing to this latter factor we shall take the
unconscious system as the starting-point of dream-formation. Like
all other thought structures, this dream-instigator will make an
effort to advance into the
Pcs
. and from there to obtain
access to consciousness.

  
¹
[
Footnote added
1919:] If we
attempted to proceed further with this schematic picture, in which
the systems are set out in linear succession, we should have to
reckon with the fact that the system next beyond the
Pcs
. is
the one to which consciousness must be ascribed - in other words,
that
Pcpt
. =
Cs
.

The Interpretation Of Dreams

975

   Experience shows us that this
path leading through the preconscious to consciousness is barred to
the dream-thoughts during the daytime by the censorship imposed by
resistance. During the night they are able to obtain access to
consciousness; but the question arises as to how they do so and
thanks to what modification. If what enabled the dream-thoughts to
achieve this were the fact that at night there is a lowering of the
resistance which guards the frontier between the unconscious and
the preconscious, we should have dreams which were in the nature of
ideas and which were without the hallucinatory quality in which we
are at the moment interested. Thus the lowering of the censorship
between the two systems
Ucs
. and
Pcs
. can only
explain dreams formed like ‘Autodidasker’ and not
dreams like that of the burning child which we took as the
starting-point of our investigations.

   The only way in which we can
describe what happens in hallucinatory dreams is by saying that the
excitation moves in a
backward
direction. Instead of being
transmitted towards the
motor
end of the apparatus it moves
towards the
sensory
end and finally reaches the perceptual
system. If we describe as ‘progressive’ the direction
taken by psychical processes arising from the unconscious during
waking life, then we may speak of dreams as having a
‘regressive’ character.¹

  
¹
[
Footnote added
1914:] The first
hint at the factor of regression is to be found as far back as in
Albertus Magnus. The ‘
imaginatio
’, he tells us,
constructs dreams out of the stored-up images of sensory objects;
and the process is carried out in a reverse direction to that in
waking life. (Quoted by Diepgen, 1912, 14.) - Hobbes writes in the
Leviathan
(1651, Pt. I, Chapter 2): ‘In sum, our
dreams are the reverse of our waking imaginations, the motion, when
we are awake, beginning at one end, and when we dream at
another.’ (Quoted by Havelock Ellis, 1911, 109.)

The Interpretation Of Dreams

976

   This regression, then, is
undoubtedly one of the psychological characteristics of the process
of dreaming; but we must remember that it does not occur only in
dreams. Intentional recollection and other constituent processes of
our normal thinking involve a retrogressive movement in the
psychical apparatus from a complex ideational act back to the raw
material of the memory-traces underlying it. In the waking state,
however, this backward movement never extends beyond the mnemic
images; it does not succeed in producing a hallucinatory revival of
the
perceptual
images. Why is it otherwise in dreams? When
we were considering the work of condensation in dreams we were
driven to suppose that the intensities attaching to ideas can be
completely transferred by the dream-work from one idea to another.
It is probably this alteration in the normal psychical procedure
which makes possible the cathexis of the system
Pcpt
. in the
reverse direction, starting from thoughts, to the pitch of complete
sensory vividness.