the thought. Thus _all_ particular needs are in danger of being
left unsatisfied when no particular need is fixed upon as the object.
It is the growing consciousness of the great waste in such study that
has changed botany in many places into horticulture and agriculture,
chemistry into the chemistry of the kitchen, and that has caused
portions of many other studies to be approached from the human view-
point.

This indicates the positive acceptance of specific purposes as guides
in study. They are not by any means full guarantees of an outcome of
knowledge in conduct, for they are only the plans by which the student
hopes that his knowledge will function. Since plans often fail of
accomplishment, these purposes may never be realized. But they give
promise of some outcome and form one important step in a series of
steps necessary for the fruition of knowledge.

_By whom and when such purposes should be conceived_

The aims set up by advanced scholars are necessarily an outgrowth of
their individual experience and interests. Such aims must, therefore,
vary greatly. For this reason such men must conceive their purposes
for themselves; there is no one who can do it for them.

Younger students are in much the same situation, for their aims should
also be individual to a large extent. Text-books might be of much help
if their authors attempted this task with skill. But authors seldom
attempt it at all; and, even if they do, they are under the
disadvantage of writing for great numbers of persons living in widely
different environments. Any aims that they propose must necessarily be
of a very general character. Teachers might again be of much help; but