perception.

THE ACCURACY OF PERCEPTS DEPENDS ON EXPERIENCE.--We must perceive
objects through our motor response to them as well as in terms of
sensations. The boy who has his knowledge of a tennis racket from
looking at one in a store window, or indeed from handling one and
looking it over in his room, can never know a tennis racket as does the
boy who plays with it on the court. Objects get their significance not
alone from their qualities, but even more from their use as related to
our own activities.

Like the child, we must get our knowledge of objects, if we are to get
it well, from the objects themselves at first hand, and not second hand
through descriptions of them by others. The fact that there is so much
of the material world about us that we can never hope to learn it all,
has made it necessary to put down in books many of the things which have
been discovered concerning nature. This necessity has, I fear, led many
away from nature itself to books--away from the living reality of things
to the dead embalming cases of words, in whose empty forms we see so
little of the significance which resides in the things themselves. We
are in danger of being satisfied with the _forms_ of knowledge without
its _substance_--with definitions contained in words instead of in
qualities and uses.

NOT DEFINITIONS, BUT FIRST-HAND CONTACT.--In like manner we come to know
distance, form and size. If we have never become acquainted with a mile
by actually walking a mile, running a mile, riding a bicycle a mile,
driving a horse a mile, or traveling a mile on a train, we might listen
for a long time to someone tell how far a mile is, or state the distance
from Chicago to Denver, without knowing much about it in any way except
word definitions. In order to understand a mile, we must come to know it
in as many ways as possible through sense activities of our own.
Although many children have learned that it is 25,000 miles around the
earth, probably no one who has not encircled the globe has any
reasonably accurate notion just how far this is. For words cannot take
the place of perceptions in giving us knowledge. In the case of shorter
distances, the same rule holds. The eye must be assisted by experience
of the muscles and tendons and joints in actually covering distance, and
learn to associate these sensations with those of the eye before the
eye alone can be able to say, "That tree is ten rods distant." Form and
size are to be