ollow another analogy, attention is to the energies of the mind what
the pipe line leading into the power plant is to the water in the canyon
above. It directs and concentrates for the generation of power. Just as
the water might run on and on to little or no purpose, so the energies
of a boy or girl may be permitted to drift aimlessly toward no
conviction unless the teacher wins him to an attention that rivets truth
to his life.

In a discussion of attention the question of the relation of interest to
attention is bound to arise. Do we attend to things because they are
interesting? Or are we interested in things because we give them our
attention? The two terms are so interwoven in meaning that they are
frequently treated under one chapter heading. Our purpose here is not to
attempt to divorce them, but rather to give them emphasis because of
their significance in the teaching process.

Attention denotes a focusing of mental energy on a particular idea or
object; interest, subjectively considered, is an attitude of mind.
Perhaps we can get a clearer idea of the two terms if we consider the
various types of attention. First of all there is what is called
_Involuntary_ attention. This is the type over which the mind has little
or no control. A person sits reading--his attention fixed on the page in
front of him--when suddenly a rock crashes through the window
immediately behind him. He jumps to see what is wrong. His attention to
his book is shifted to the window, not because he wills it so, but
because of the suddenness and force of the stimulus. The excitation of
the auditory nerve centers compels attention. The attendant feeling may
be one of pleasure or of pain--there may be an interest developed or
there may not. Involuntary attention clearly does not rest upon
interest.

Then there is what is called _Nonvoluntary_ attention. I go to a theatre
and some particular musical number is featured. It grips my interest and
I follow it with rapt attention, wholly without conscious effort. Unlike
the case of a sudden noise, in this experience my attention is not
physiologically automatic--I could control it if I chose--but I choose
now to give it. Interest clearly is the motor power behind such
attention. Then, finally, there is _Voluntary_ attention. I sit at a
table working out a problem in arithmetic. Outside there is being played
a most exciting ball game. My interests are almost wholly centered in
the outcome of the g