in advance, if we are psychologists, that certain methods will be wrong,
so our psychology saves us from mistakes. It makes us, moreover, more
clear as to what we are about. We gain confidence in respect to any
method which we are using as soon as we believe that it has theory as
well as practice at its back. Most of all, it fructifies our
independence, and it reanimates our interest, to see our subject at two
different angles,--to get a stereoscopic view, so to speak, of the
youthful organism who is our enemy, and, while handling him with all our
concrete tact and divination, to be able, at the same time, to represent
to ourselves the curious inner elements of his mental machine. Such a
complete knowledge as this of the pupil, at once intuitive and analytic,
is surely the knowledge at which every teacher ought to aim.

Fortunately for you teachers, the elements of the mental machine can be
clearly apprehended, and their workings easily grasped. And, as the most
general elements and workings are just those parts of psychology which
the teacher finds most directly useful, it follows that the amount of
this science which is necessary to all teachers need not be very great.
Those who find themselves loving the subject may go as far as they
please, and become possibly none the worse teachers for the fact, even
though in some of them one might apprehend a little loss of balance from
the tendency observable in all of us to overemphasize certain special
parts of a subject when we are studying it intensely and abstractly. But
for the great majority of you a general view is enough, provided it be a
true one; and such a general view, one may say, might almost be written
on the palm of one's hand.

Least of all need you, merely _as teachers_, deem it part of your duty
to become contributors to psychological science or to make psychological
observations in a methodical or responsible manner. I fear that some of