ing of his nature. The
teacher must have regard, not only to the materials and the method used
in training, but also to the being who is to be trained. A knowledge of
child nature will prevent expensive mistakes and needless waste.

A few typical examples will serve to illustrate the immense importance a
knowledge of child nature is to his teacher.

1. As has been already explained, when the teacher knows something about
the instincts of children, he will utilize these tendencies in his
teaching and work with them, not against them. He will, wherever
possible, make use of the play instinct in his lessons, as for example,
when he makes the multiplication drill a matter of climbing a stairway
without stumbling or crossing a stream on stones without falling in. He
will use the instinct of physical activity in having children learn
number combinations by manipulating blocks, or square measure by
actually measuring surfaces, or fractions by using scissors and strips
of cardboard, or geographical features by modelling in sand and clay. He
will use the imitative instinct in cultivating desirable personal
habits, such as neatness, cleanliness, and order, and in modifying
conduct through the inspiring presentation of history and literature. He
will provide exercise for the instinct of curiosity by suggesting
interesting problems in geography and nature study.

2. When the teacher understands the principle of eliminating undesirable
tendencies by substitution, he will not regard as cardinal sins the
pushing, pinching, and kicking in which boys give vent to their excess
energy, but will set about directing this purposeless activity into more
profitable channels. He will thus substitute another means of
expression for the present undesirable means. He will, for instance,
give opportunity for physical exercises, paper-folding and cutting,
cardboard work, wood-work, drawing, colour work, modelling, etc., so far
as possible in all school subjects. He will try to transform the boy who
teases and bullies the smaller boys into a guardian and protector. He
will try to utilize the boy's tendency to collect useless odds and ends
by turning it into the systematic and purposeful collection of plants,
insects, specimens of soils, specimens illustrating phases of
manufactures, postage stamps, coins, etc.

3. When the teacher knows that the interests of pupils have much to do
with determining their effort, he will endeavour to seize upon thes