of it. All I can say is, we must expect something of the sort from our general knowledge of human nature, and in any investigations in which the inner attitude is of very great importance, as for example in experiments on sense perception, we must give special heed to its misleading influence.
It is evident how this influence in general makes itself felt. With average values it would tend to level the extremes; where especially large or small numbers are expected it would tend to further increase or decrease the values. This influence can only be avoided with certainty when the tests are made by two persons working together, one of whom acts as subject for a certain time without raising any questions concerning the purpose or the result of the investigations. Otherwise help can be obtained only by roundabout methods, and then, probably, only to a limited extent. The subject, as I myself always did, can conceal from himself as long as possible the exact results. The investigation can be extended in such a way that the upper limits of the variables in question are attained. In this way, whatever warping of the truth takes place becomes relatively more difficult and unimportant. Finally, the subject can propose many problems which will appear to be independent of each other in the hope that, as a result, the true relation of the interconnected mental processes will break its way through.
To what extent the sources of error mentioned have affected the results given below naturally cannot be exactly determined. The absolute value of the numbers will doubtless be frequently influenced by them, but as the purpose of the tests could never have been the precise determination of absolute values, but rather the attainment of comparative results (especially in the numerical sense) and relatively still more general results, there is no reason for too great anxiety. In one important case (§ 38) I could directly convince myself that the exclusion of all knowledge concerning the character of the results brought about no change; in another case where I myself could not eliminate a doubt I called especial attention to it. In any case he who is inclined a priori to estimate very highly the unconscious influence of secret wishes on the total mental attitude will also have to take into consideration that the secret wish to find objective truth and not with disproportionate toil to place the creation of his own fancy upon the feet of clay—that this wish,
