or_, after all, is
worth more than a mind grown corpulent and lazy with an excess of
pabulum, overfed. The cultivation therefore of a many-sided interest
ceases to be a blessing as soon as encyclopedic knowledge becomes its
aim. In fact the desire on the part of teachers to make the knowledge
of any subject complete and encyclopedic destroys all true interest.
The solution of this great problem does not consist in identifying
many-sided interest with encyclopedic knowledge, but in such a detailed
study of _typical_ forms in each case as will give insight into that
branch without any pretension to exhaustive knowledge. Certainly a
true interest in plants does not require that we become acquainted with
all the species of all the genera. But a proper study of a few typical
forms in a few of the families and genera might produce a much deeper
interest in nature and in her laws.

The culture of a many-sided interest is essential to a full development
and _perfection_ of the mental activities. It is easy to see that
interest in any subject gives all thought upon it a greater vigor and
intensify. Mental action in all directions is strengthened and
vivified by a direct interest. On the other hand mental life
diminishes with the loss of interest, and even in fields of knowledge
in which a man has displayed unusual mastery, a loss of interest is
followed by a loss of energy. Excluding interest is like cutting off
the circulation from a limb. Perfect vigor of thought which we aim at
in education, is marked by strength along three lines, the vigor of the
individual ideas, the extent and variety of ideas under control, and
the connection and harmony of ideas. It is the highest general aim of
intellectual education to strengthen mental vigor in these three
directions. Many-sided interest is conducive to all three. Every
thought that finds lodgment in the mind is toned up and strengthened by
interest. It is also easier to retain and reproduce some idea that has
once been grasped with full feeling of interest. An interest that has
been developed along all leading lines of study has a proper breadth
and comprehensiveness and cannot be hampered and clogged by narrow
restraints and prejudice. We admire a person not simply because he has
a few clear ideas, but also for the extent and variety of this sort of
information. Our admiration ceases when he shows ignorance or
prejudice or lack of sympathy with important branches of