study.
Finally, the unity and harmony of the varied kinds of knowledge are a
great source of interest. The tracing of connections between different
studies and the insight that comes from proper associations, are among
the highest delights of learning. The connection and harmony of ideas
will be discussed under concentration.

The six interests above mentioned are to be developed along parallel
lines. They are to be kept in proper _equipoise_. It is not designed
that anyone shall be developed to the overshadowing of the others.
They are like six pillars upon which the structure of a liberal
education is rested. A cultivation of any one, exclusively, may be in
place when the work of general education is complete and a profession
or life labor has been chosen.

It is also true that a proper interest is a _protection_ against the
desires, disorderly impulses, and passions. One of the chief ends of
education is to bring the inclinations and importunate desires under
mastery, to establish a counterpoise to them by the steady and
persistent forces of education. A many-sided interest cultivated along
the chief paths of knowledge, implies such mental vigor and such
preoccupation with worthy subjects as naturally to discourage unworthy
desires.

Locke says, self-restraint, the mastery over one's inclinations, is the
foundation of virtue. "He that has found a way how to keep a child's
spirit easy, active, and free, and yet at the same time to restrain him
from many things he has a mind to, and to draw him to things that are
uneasy to him; he, I say, that knows how to reconcile these seeming
contradictions, has, in my opinion, got the true secret of education."
But it is a secret still; the central question remains unanswered. How
is the teacher to approach and influence the will of the child? Is it
by supposing that the child has a will already developed and strong
enough to be relied upon on all occasions? On the contrary, must not
the teacher put incentives in the path of the pupil, ideas and feelings
that prompt him to self-denial?

Interest as a source of _will-stimulus_ has peculiar advantages. It is
not desired that the inclinations and feelings shall get the mastery of
the mind, certainly not the disorderly and momentary desires. Higher
desires, indeed, should properly influence the will, as the desire of
the approval of conscience, the desire to attain excellence, to gain
strength and mastery, to serve