The Nature Of Perception





HOW A PERCEPT IS FORMED.--How, then, do we proceed to the discovery of

this world of objects? Let us watch the child and learn the secret from

him. Give the babe a ball, and he applies every sense to it to discover

its qualities. He stares at it, he takes it in his hands and turns it

over and around, he lifts it, he strokes it, he punches it and jabs it,

he puts it to his mouth and bites it, he drops it, he throws it and

creeps after it. He leaves no stone unturned to find out what that thing

really is. By means of the qualities which come to him through the

avenues of sense, he constructs the object. And not only does he come

to know the ball as a material object, but he comes to know also its

uses. He is forming his own best definition of a ball in terms of the

sensations which he gets from it and the uses to which he puts it, and

all this even before he can name it or is able to recognize its name

when he hears it. How much better his method than the one he will have

to follow a little later when he goes to school and learns that A ball

is a spherical body of any substance or size, used to play with, as by

throwing, kicking, or knocking, etc.!



THE PERCEPT INVOLVES ALL RELATIONS OF THE OBJECT.--Nor is the case in

the least different with ourselves. When we wish to learn about a new

object or discover new facts about an old one, we do precisely as the

child does if we are wise. We apply to it every sense to which it will

afford a stimulus, and finally arrive at the object through its various

qualities. And just in so far as we have failed to use in connection

with it every sense to which it can minister, just in that degree will

we have an incomplete perception of it. Indeed, just so far as we have

failed finally to perceive it in terms of its functions or uses, in that

far also have we failed to know it completely. Tomatoes were for many

years grown as ornamental garden plants before it was discovered that

the tomatoes could minister to the taste as well as to the sight. The

clothing of civilized man gives the same sensation of texture and color

to the savage that it does to its owner, but he is so far from

perceiving it in the same way that he packs it away and continues to go

naked. The Orientals, who disdain the use of chairs and prefer to sit

cross-legged on the floor, can never perceive a chair just as we do who

use chairs daily, and to whom chairs are so saturated with social

suggestions and associations.



THE CONTENT OF THE PERCEPT.--The percept, then, always contains a basis

of sensation. The eye, the ear, the skin or some other sense organ

must turn in its supply of sensory material or there can be no percept.

But the percept contains more than just sensations. Consider, for

example, your percept of an automobile flashing past your windows. You

really see but very little of it, yet you perceive it as a very

familiar vehicle. All that your sense organs furnish is a more or less

blurred patch of black of certain size and contour, one or more objects

of somewhat different color whom you know to be passengers, and various

sounds of a whizzing, chugging or roaring nature. Your former experience

with automobiles enables you to associate with these meager sensory

details the upholstered seats, the whirling wheels, the swaying movement

and whatever else belongs to the full meaning of a motor car.



The percept that contained only sensory material, and lacked all memory

elements, ideas and meanings, would be no percept at all. And this is

the reason why a young child cannot see or hear like ourselves. It lacks

the associative material to give significance and meaning to the sensory

elements supplied by the end-organs. The dependence of the percept on

material from past experience is also illustrated in the common

statement that what one gets from an art exhibit or a concert depends on

what he brings to it. He who brings no knowledge, no memory, no images

from other pictures or music will secure but relatively barren percepts,

consisting of little besides the mere sensory elements. Truly, to him

that hath shall be given in the realm of 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 learned in the same way. The hands must actually touch

and handle the object, experiencing its hardness or smoothness, the way

this curve and that angle feels, the amount of muscular energy it takes

to pass the hand over this surface and along that line, the eye taking

note all the while, before the eye can tell at a glance that yonder

object is a sphere and that this surface is two feet on the edge.





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