lities of the mind and the deeper traits. The so-called
impressions, too, are determined by the most secondary and external
factors. Society relies instinctively on the hope that the natural
wishes and interests will push every one to the place for which his
dispositions, talents, and psychophysical gifts prepare him.

In reality this confidence is entirely unfounded. A threefold
difficulty exists. In the first place, young people know very little
about themselves and their abilities. When the day comes on which they
discover their real strong points and their weaknesses, it is often
too late. They have usually been drawn into the current of a
particular vocation, and have given too much energy to the preparation
for a specific achievement to change the whole life-plan once more.
The entire scheme of education gives to the individual little chance
to find himself. A mere interest for one or another subject in school
is influenced by many accidental circumstances, by the personality of
the teacher or the methods of instruction, by suggestions of the
surroundings and by home traditions, and accordingly even such a
preference gives rather a slight final indication of the individual
mental qualities. Moreover, such mere inclinations and interests
cannot determine the true psychological fitness for a vocation. To
choose a crude illustration, a boy may think with passion of the
vocation of a sailor, and yet may be entirely unfit for it, because
his mind lacks the ability to discriminate red and green. He himself
may never have discovered that he is color-blind, but when he is ready
to turn to the sailor's calling, the examination of his
color-sensitiveness which is demanded may have shown the disturbing
mental deficiency. Similar defects may exist in a boy's attention or
memory, judgment or feeling, thought or imagination, suggestibility or
emotion, and they may remain just as undiscovered as the defect of
color-blindness, which is characteristic of four per cent of the male
population. All such deficiencies may be dangerous in particular
callings. But while the vocation of the ship officer is fortunately
protected nowadays by such a special psychological examination, most
other vocations are unguarded against the entrance of the mentally
unfit individuals.

As the boys and girls grow up without recognizing their psychical
weaknesses, the exceptional strength of one or another mental function
too often remains unnoticed by