The teacher ought not to grow old. To be sure, time will lay its hand on
him, as it does on others; but he should always cultivate in himself the
feelings, sentiments, and even ambitions of youth. Far enough removed
from his pupils in age and position to stimulate them by his example,
and encourage them by his precepts, he should yet be so near them that
he can appreciate the steps and struggles which mark their progress in
the path of learning. There must be some points of contact, something
common to teacher and pupils. Indeed, for us all it is true that age
loses nothing of its dignity or respect when it accepts the sentiments
and sports of youth and childhood. But above all should the teacher
remember the common remark of La Place, in his Celestial Mechanics, and
the observation of Dr. Bowditch upon it. 'Whenever I meet in La Place
with the words, "Thus it plainly appears," I am sure that hours, and
perhaps days, of hard study, will alone enable me to discover _how_ it
plainly appears.' The good teacher will seek first to estimate each
scholar"s capacity, and then adapt his instructions accordingly. Though
he may be far removed from his pupils in attainments, he should be able
to mark the steps by which ordinary minds pass from common principles to
their noblest application.
