The Crisis in Psychology

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We must use it to the extent that it is useful, but there is no need to pronounce

judgments of principle about it—e.g., about the limitations of the knowledge ob-

tained with it, its reliability, or the nature of the knowledge determined by it. Engels

demonstrated how little the natural construction of the eye determines the bounda-

ries of our knowledge of the phenomena of light. Planck says the same on behalf

of contemporary physics. To separate the fundamental psychological concept from

the specific sensory perception is psychology’s next task. This sensation itself, self-

observation itself, must be explained (like the eye) from the postulates, methods,

and universal principles of psychology. It must become one of psychology’s particu-

lar problems.

When we accept this, the question of the nature of interpretation, i.e., the

indirect method, arises. Usually it is said that history interprets the traces of the

past, whereas physics observes the invisible as directly as the eye does by means

of its instruments. The instruments are the extended organs of the researcher. After

all, the microscope, telescope, telephone etc. make the invisible visible and the sub-

ject of immediate experience. Physics does not interpret, but sees.

But this opinion is false. The methodology of the scientific instrument has long

since clarified a new role for the instrument which is not always obvious. Even the

thermometer may serve as an example of the introduction of a fundamentally new

principle into the method of science through the use of an instrument. On the

thermometer we read the temperature. It does not strengthen or extend the sen-

sation of heat as the microscope extends the eye; rather, it totally liberates us from

sensation when studying heat. One who is unable to sense heat or cold may still

use the thermometer, whereas a blind person cannot use a microscope. The use of

a thermometer is a perfect model of the indirect method. After all, we do not study

what we see (as with the microscope)—the rising of the mercury, the expansion of

the alcohol—but we study heat and its changes, which are indicated by the mercury

or alcohol. We interpret the indications of the thermometer, we reconstruct the

phenomenon under study by its traces, by its influence upon the expansion of a

substance. All the instruments Planck speaks of as means to study the invisible are

constructed in this way. ‘Tb interpret, consequently, means to re-create a phenome-

non from its traces and influences relying upon regularities established before (in

the present case—the law of the extension of solids, liquids, and gases during heat-

ing). There is no fundamental difference whatsoever between the use of a ther-

mometer on the one hand and interpretation in history, psychology, etc. on the

other. The same holds true for any science: it is not dependent upon sensory per-

ception.

Stumpf mentions the blind mathematician Saunderson who wrote a textbook

of geometry; Shcherbina (1908)23 relates that his blindness did not prevent him

from explaining optics to sighted people. And, indeed, all instruments mentioned

by Planck can be adapted for the blind, just like the watches, thermometers, and

books for the blind that already exist, so that a blind person might occupy himself

with optics as well. It is a matter of technique, not of principle.

Korniov (1922)24 beautifully demonstrated that (1) disagreement about the

procedural aspect of the design of experiments makes for conflicts which lead to

the formation of different currents in psychology, just as the different philosophies

about the chronoscope—which resulted from the question as to in which room this

apparatus should be placed during the experiments—determined the question of

the whole method and system of psychology and divided Wundt’s school from

KUlpe’s; and (2) the experimental method introduced nothing new into psychology.

For Wundt it is a correction of self-observation. For Ach~ the data of self-obser-

vation can only be checked against other data of self-observation, as if the sensation