ider classes of relation between
things, of which we take cognizance, are all got into the mind at a
comparatively youthful date. Few men ever do acquaint themselves with
the principles of a new science after even twenty-five. If you do not
study political economy in college, it is a thousand to one that its
main conceptions will remain unknown to you through life. Similarly with
biology, similarly with electricity. What percentage of persons now
fifty years old have any definite conception whatever of a dynamo, or
how the trolley-cars are made to run? Surely, a small fraction of one
per cent. But the boys in colleges are all acquiring these conceptions.

There is a sense of infinite potentiality in us all, when young, which
makes some of us draw up lists of books we intend to read hereafter, and
makes most of us think that we can easily acquaint ourselves with all
sorts of things which we are now neglecting by studying them out
hereafter in the intervals of leisure of our business lives. Such good
intentions are hardly ever carried out. The conceptions acquired before
thirty remain usually the only ones we ever gain. Such exceptional cases
of perpetually self-renovating youth as Mr. Gladstone's only prove, by
the admiration they awaken, the universality of the rule. And it may
well solemnize a teacher, and confirm in him a healthy sense of the
importance of his mission, to feel how exclusively dependent upon his
present ministrations in the way of imparting conceptions the pupil's
future life is probably bound to be.

XV. THE WILL

Since mentality terminates naturally in outward conduct, the final
chapter in psychology has to be the chapter on the will. But the word
'will' can be used in a broader and in a narrower sense. In the broader
sense, it designates our entire capacity for impulsive and active life,
including our instinctive reactions and those forms of behavior that
have become secondarily automatic and semi-unconscious through frequent
repetition. In the narrower sense, acts of will are such acts only as
cannot be inattentively performed. A distinct idea of what they are, and
a deliberate _fiat_ on the mind's part, must precede their execution.

Such acts are often characterized by hesitation, and accompanied by a
feeling, altogether peculiar, of resolve, a feeling which may or may not
carry with it a further feeling of effort. In my earlier talks, I said
so much of our impulsive tendencies that I