experience, is taken as decisive, the fundamental question will be how
these factors produce a definite organization, apparent in the visual
field, or elsewhere. As far as I can see the only answers are, in the
first case, that our overt movements are organized in exactly the
same manner physiologically which, to naïve observation, is plainly
given, for instance, in the visual field; or, in the second case, that
kinesthetic experiences, and perhaps their reproductions, exhibit
that organization. Whatever the process may be, by which organization
is supposed to be introduced into the chief sensory field, which for
most persons is that of vision, it cannot be imported without existing
beforehand in whichever region it is said to have its origin. As
long as we consider peripheral movements or sequences of kinesthetic
experiences as a series of instantaneous events which follow each
other independently and indifferently, it will hardly be possible to
use them to explain the occurrence of definite segregated wholes and
groups anywhere. Let us take the bright point moving in dark space as
an example. If we say that the observer talks about three or seven
movements in this case, because he makes or experiences three or seven
eye-movements, we are presupposing the same organization in the
temporal and spatial sequence of eye-movements, or the experiences of
them, which I personally seem to have in the visual field _as such_.
Otherwise the observer might as well report 53 or 29 or any other
number of events, for apart from organization such an enumeration would
be no more arbitrary than that of three or seven parts.
I was once told that all the observations of _gestalt_ psychology are
very old and have long been explained by the kinesthetic experiences
which occur during eye-movements. This sounds as though a hint about
the kinesthetic experiences accompanying vision were satisfactory as
an explanation of the phenomena of visual organization. But we see
that, instead of having solved the problem, we have only shifted it
from one place to another, for now we have to solve the problem of
the segregation of wholes in the temporal and spatial extension of
kinesthetic experiences.
I shall not deny that the problem of organization exists in the field
of movements and kinesthetic experiences. On the contrary, I am
convinced that the facts in either of these fields cannot be understood
rightly without taking our point of view. But why should movements and
the processes underlying kinesthetic experience be the only material
capable of being organized, or of being treated from the viewpoint of
_gestalt_ theory? If organization is physiologically possible in one
field, why not in others? In order to explain the apparent organization
of visual experience by accompanying motor experiences, one must assume
spatial as well as temporal organization of these motor phenomena. I
do not see any reason why such organization should be excluded from
optics and acoustics. If there are some more general grounds for the
exclusion, I am not yet aware of them. In the meantime we shall not
discuss the difficulties which would arise, were we to try to explain
_concrete_ particular cases of visual organization by motor phenomena,
for in the next chapter we shall again return to the question of
indirect explanations of organization.
After what has been said about organization, we cannot be surprised
to learn that serious lesions in the optical center of the brain may
produce a kind of “blindness” in persons, who at the same time are not
deprived of vision. Careful examination of such a case by Gelb and
Goldstein[29] has shown that, here, the field of vision has undergone
a radical change, organization having disappeared almost completely,
so that the field shows a more or less chaotic character. Where he
fixes his attention, the patient is able to grasp some small fraction
of a line, for instance, but he can no longer see extended wholes as
clear-cut forms. It is particularly interesting to observe that this
patient begins spontaneously to rely to a great degree upon motor
experience instead of vision. Following the fractions of contours,
which are clearer to him, with movements of the eye, he is able in
time to build up motor wholes and to recognize them. So, if his name
is written on a blackboard, he will follow the first letters and
soon guess the rest. But it is possible to exclude this procedure by
a simple trick: draw a few lines, which have the same color as the
letters, across the name. Since to the patient the name is never given
optically as one simultaneously and well-organized whole, and since
now he does not see it as one thing and the crossing lines as another
pattern apart from it, he will follow parts of a letter or parts of
the crossing lines indifferently. The result is that he cannot read
the name under these circumstances. The example shows, by the way, how
much motor function, accompanying vision, depends itself upon normal
visual organization. Organization being a matter of extended regions
of the field, wherever only local fractions may become organized to
some degree, the _control_ which organization in a large area normally
exerts upon the motor function, is made impossible, and results like
those I have just mentioned become inevitable.
But why should wholes, detached by the operations of sensory dynamics,
correspond so generally to objects, or things, in the practical meaning
of the words? Do we have to assume that a surprising harmony is
established between the laws of sensory dynamics and the area or the
limits of physical things around us? No such assumption need be made,
for there are exceptions to the correspondence of sensory organization
and physical units. Take all the cases of groups of separate members,
the constellations in the sky, the examples of dots forming definite
groups (Fig. 1) above, the instances of grouping in ornaments, the
parts of which are, in their physical nature, indifferent to each
other, i.e., without functional interrelation. In countless cases
organization is a sensory reality without there being a corresponding
physical unit. Also, continuous sensory wholes may occur in the absence
of an homologous physical unit. The reader himself at some time has
seen a strange object, perfectly unknown to him, which later on,
perhaps after some movement of his head and eyes, metamorphosed into
a single well-known thing and some part of another one, these two
together having been, at first, unified and segregated as one unknown
whole. The same example shows that sometimes to a definite physical
object there does not correspond a sensory unit, because in vision
its parts have been absorbed by surrounding areas which happen to
have qualities appropriate to this effect. This was the case in the
puzzle-pictures which years ago amused the readers of magazines. And in
the last war it became a real art to make things, guns, cars, boats,
disappear at some distance by painting upon them an irregular design,
the parts of which would form indifferent spots by intermingling with
parts of their environment. The objects themselves are destroyed as
optical realities and in their place appear meaningless patches which
do not arouse military suspicion, since similar patches are produced
constantly by the accidental properties of country and sea.
On the other hand, it is not difficult to explain why visual units in
general correspond to physical objects. The things around us are either
made by man or are products of nature. Objects of the first class are
prepared for our purposes. Therefore, we give them a form and surface,
etc., so that they are likely to be seen without difficulty. Without
knowing the principles of sensory organization in an abstract form, man
works in conformity with them, and so the physical units which are the
products of his art will appear as visual units. Furthermore, it is
not easy to create a somewhat compact object which, when placed in a
simple environment, would not fulfill the general conditions of visual
segregation. Camouflage is a difficult art.
With objects produced by nature, the situation is not altogether
different. A condition fulfilled by most natural things is the presence
of one class of surface properties in contact with another class of
surrounding surface properties. This difference is due to the fact
that the common origin of the parts of one thing will probably make
them similar, whereas in the surroundings the surface properties
will generally be of a different character. Therefore, one condition
of visual segregation is given in the case of most things. Even if
a stone lies half-embedded in the sand, which is nothing but tiny
fractions of the same kind of stone, the difference of coherence, and
therefore of “inner detail,” between the surface-elements of the stone
and those of the sand will be sufficient in most cases to make the
stone optically one thing. At least, at the boundary between a natural
object and its surroundings some discontinuity of properties almost
universally prevails. This discontinuity separates the environment from
the interior of the object by a closed outline. Since, as a rule, that
will suffice to make even a meaningless area appear as a segregated
whole in the sensory field, it will certainly have that effect where
the boundary of a physical object is concerned. If there are no such
differences and no discontinuity whatever between the object and its
surroundings, no visual unit will exist, it is true. But try to find
objects which, without fulfilling any of the conditions of sensory
segregation, are still plainly before you, because of the influence
of meaning! You will have a hard task. Our general experience shows
that wherever the conditions of visual segregation work against a
unit, it will not exist in the sensory field of a naïve observer, even
if it is well-known as such and is camouflaged only momentarily by
special circumstances. A more detailed discussion would have to treat
here the problem of visual depth and the segregation of things as
three-dimensional wholes. But, though this question is of the greatest
importance for the correspondence of physical units and sensory
segregations, I must leave it untouched for the present, because as
yet in this field experimentation as well as theory is in a rather
undeveloped state.
In the last paragraphs I have laid some stress upon the fact that
organization in a sensory field is something which originates as a
characteristic achievement of the nervous system. This emphasis has
become necessary because some psychologists have recently said that,
according to _gestalt_ psychology, “_gestalten_,” i.e., segregated
sensory wholes in this connection, exist outside the organism and
simply extend or project themselves into it. This is so absolutely
wrong that I cannot comprehend how the misunderstanding arose.[30]
But after what we have seen, it is quite another problem to ask how
far sensory organization, though being a characteristic achievement
of the nervous system, may have an objective value at the same time.
Between the physical objects around us and our eyes waves of light are
the only means of communication. These do not bring the “_gestalten_”
ready-made into the organism; rather, the segregation of wholes occurs
in the nervous system; but the result may tell more about some of the
objective properties of the world around us than the rays of light
would be able to do. We do not always learn more about an object, the
nearer we approach it. For instance, when a lens is put in the way of
the light reflected by a bright object, it would not be wise, for the
purpose of getting a clear image of the object, to bring the screen as
near as possible to the lens (and thereby the object); at a certain
distance the projection tells much more about the object than nearer
by. Similarly, sensory organization may give us a “truer” picture of
the world around us in some respects than the rays of light, though
these are the first messengers coming from the objects and sensory
organization occurs later on and farther off.
Indeed, the waves of light do not contain the slightest indication of
any organization or any “belonging together” which may exist among the
parts of the objects by which they are reflected. Each element of the
physical surface reflects light independently and, as reflectors, two
elements of the surface of a sheep, for instance, have no more to do
with each other than one of them has to do with a surface element in
the animal’s environment. In reflection, therefore, no trace is left
of those units which exist in the physical world; they are dispersed
completely into an indifferent mass of rays, all equally independent
of each other. By the refractory properties of our eye those rays,
which come from one point in the outside world, are made to converge
upon one point of the retina; also the geometrical relations of the
points on the surface of an object are reconstructed here, in large
measure. Still, each local stimulus thus achieved is an independent
affair, and rays coming from elements of the surface of one physical
object, the sheep for instance, are as indifferent to each other
as they are to stimuli from the sheep’s environment. So we have no
organization at all in retinal stimulation, no wholes, no groups, no
segregation. It cannot be asserted, in opposition, that there is one
definite area or patch on the retina as the image of the animal, for
the elements of this area are as independent of each other functionally
as any one of them is independent of an element outside the image. In
psychology much has been said about the stimulus-error which consists
in our confusing our knowledge about the physical conditions of sensory
experience with experience as such. But another mistake, which I
propose to call the _experience-error_, is not less unfortunate. It
occurs when we unintentionally attribute certain properties of sensory
experience to the actual constellation of stimuli, properties which
are so very common that we tend to apply them to whatever we are
thinking about. This is the case primarily, wherever we have not yet
learned to see the _problem_ contained in those common properties of
experience. No wonder, then, that neurologists and some psychologists
still talk about “_the_ retinal process” corresponding to an object,
as though there were something like a segregated functional unit on
the retina. Whereas as a matter of fact the whole retina is a mosaic
of indifferently related spots, and this is the case until sensory
organization begins physiologically.
Once we have realized, however, that stimulation, as such, is
completely unorganized, the enormous biological value of sensory
organization will become apparent. Since the rules governing this
organization conform to the structure of objective units, to objective
divisions, to objective “belonging together,” in very many cases the
result of their operation is a kind of reconstruction of those aspects
of the objective physical situation which are temporarily lost on the
way between the objects and the sense organ. It is true that continuous
wholes are sometimes segregated, and groups of separate members are
often formed, which do not correspond to objective physical units. But
that is not a serious deficiency when compared with the indefinitely
large number of cases in which organization is a picture of objective
facts. If all the content of the sensory field were indifferent grains
of sensory stuff, it would be a hard task to orientate ourselves in
and to react to such a world. I am not sure that even after years of
trial and error with regard to such a field, a child would _learn_
to organize it. Considering the situation impartially, we may come
to the conclusion that organization of the field, as an original
sensory fact, is much more important biologically than the properties
of local stimulation are. Color-blind people are perfectly able to
adjust to their environment although their experience has fewer
nuances of stimulation than the normal. This is so because their lack
is not a serious impediment with respect to the practically important
similarities and differences in stimulation. Differences of chroma are
usually associated with differences of brightness (cf. p. 144). That
is enough for _organization_, and since most of our behavior will be
determined by this property of the field, even a large deficit as to
qualities does not matter very much.
Organization is no less important for the procedure of science than
it is for practical life. We saw in the first chapter that, as a
physicist, sensory experience is my only primary material. But what
experience? The system I am investigating, the apparatus of research,
its scale, the needle, and so forth, are all of them segregated wholes,
or sub-units, in my sensory field. If they were not given to me in
such an order of “belonging together,” physical research would be all
but impossible. About this phase of “objective method” we do not hear
very much, when behaviorists recommend the procedure of the natural
sciences to us. But we should, since, if we consider physical research
as a series of physiological events occurring in the physicist, we are
still confronted with the problem of organization as an aspect of those
events, which is absolutely indispensable for their success.
At the same time we can understand why the formula of “stimulus and
response,” though sounding well at first, is quite misleading as long
as the term “stimulus” is used as carelessly as most behaviorists
do use it. One stimulus, when taken in the strict meaning of the
word, is not followed by one definite reaction in a great many cases
(cf. Chapters III and IV). In optics, for instance, the organism
will respond to an objective constellation of millions of stimuli
by developing, first of all, an organized field, many and perhaps
the most essential properties of which have no physical partner
among the single stimuli (cf. Chapter VI). Reactions of the effector
organs may and will begin very soon, in many cases; but, as the
eye-movements show, even the first of these reactions will depend
upon the developing organization of the field, because the laws
of optically determined eye-movements refer to the boundaries of
segregated wholes, to the situation of these wholes in the field, and
to lines, but not to “sensations” as such. Apart from eye-movements,
what is called “acting” in man will be a reaction to a well-developed
field and in most cases to some definite whole in it. If, therefore,
we say that in psychology the right formula is, _Constellation of
stimuli--Organization--Reaction to results of organization_, such
a statement fits the facts incomparably better than the usual one.
The organism is not barren functionally; it is not a box containing
conductors each with a separate function; it responds to a situation,
first, by dynamical events peculiar to it _as a system_ and, then, by
behavior which depends upon the results of that dynamical organization
and order. Suppose that somewhere in a factory HNO_{3} were produced
out of its elements and that in another part of the factory the product
of that chemical organization were used to dissolve silver,--would
you say that the silver reacts to nitrogen, hydrogen and oxygen? You
certainly would not, because what happens to the silver depends upon
that chemical organization, and it cannot be understood as a reaction
either to those elements separately or to the sum of them. If that is
so, we should also be very careful before we refer to types of behavior
as being reactions to “a stimulus” or to “some stimuli.” Even the last
expression would often be quite ambiguous, because it might mean that
the behavior in question is the consequence of several stimuli working
independently at the same time, whereas it may depend upon a product of
sensory organization.
Once I tried to convince a behaviorist that referring to “a female” as
“a stimulus” for a male bird is equivalent to completely closing one’s
eyes to the problem of _gestalt_ and organization. It was not possible.
Though (or because?) he treats sensory experience as something
without any interest for psychology, the behaviorist committed the
“experience-error” so continually and pervasively that “the female
bird” remained “a stimulus” for him. How often has “a mouse,” “a
door,” “the experimenter” and so on been called “the stimulus” in
animal psychology! Innocent though this expression may be, if it is
used as an abbreviation by those who are fully aware of the problem of
organization, it will hide this problem in a most unfortunate manner
when used by an author who is not free from the “experience-error.”
I mentioned above the great biological value of sensory organization as
a reconstruction in nervous process of objective “belonging together.”
But how can it be a reconstruction if, on the way from the objects
to the sense organ, the waves of light are an unorganized mass of
independent events? There must be something in this transmission of
rays which determines the “right” organization in most cases. We have
seen, indeed, that the relations of neighborhood, of similarity and
difference among the stimuli, though these are indifferent to each
other dynamically, are in some respects a copy of the corresponding
relations among the surface-elements of surrounding objects. Some
definite relations among the stimuli as they issue from the physical
object, and the preservation of these relations in transmission,
seems to be an essential condition for the organization of units
corresponding to objects in the outer world. But if organization
of the field depends upon the relations of stimuli as these are
distributed on the retinæ, we must draw the conclusion that sensory
organization cannot be understood by considering independent local
processes as such. Now we know that, in dynamical self-distribution,
process-in-extension exists as a functional whole. So we must assume
that sensory organization, as we have considered it in this chapter,
is a property of such a dynamical distribution, occurring under
definite conditions of stimulation. At the same time we must remember
that everywhere in physics dynamics depends upon the _relations_
between given conditions. The more probable will it appear to us that
sensory organization, as depending upon the relations of stimuli, is
to be explained as an effect of sensory dynamics within the field.
By studying organization, therefore, we may be able to discover what
particular kind of dynamical events is responsible for sensory order.
_Gestalt_ psychology is said by some critics to repeat the word “whole”
continually, to neglect the existence of parts and therefore to
sacrifice that wonderful tool of all scientific procedure, analysis.
Nothing could be a more misleading statement, as may be judged
from the fact that we found it necessary to mention _segregation_
wherever we were dealing with a unit or a definite whole. In dynamical
distribution, as we have seen, the functional “interwovenness” of
a field is altogether compatible with dynamical segregation. We may
even say that in _gestalt_ analysis we find the _genuine_ “parts”
of the field as segregated wholes and groups and, in these wholes
or groups, their genuine “parts” again as subordinate wholes and
members, whereas the so-called sensations of introspective analysis are
parts existing only in construction and theory. For this very reason
analysis as a statement about “real” parts, existing in consequence
of organization, is a perfectly legitimate and necessary procedure in
_gestalt_ psychology, probably much more valuable than any analysis
into sensations which certainly no one finds segregated in his visual
field.