, learns to discriminate against
caterpillars. In a practical sense, the chick, like the rat, learns to
distinguish between stimuli that at first aroused the same response.
It is in the same way that the human being is driven to discriminate
and attend to details. He is brought to a halt by the poor results of
his first rough and ready perception, scans the situation, isolates
some detail and, finding response to this detail to bring satisfactory
results, substitutes response to this {437} detail for his first
undiscriminating response to the whole object.

The child at first treats gloves as alike, whether rights or lefts,
but thus gets into trouble, and is driven to look at them more sharply
till he perceives the special characteristics of rights and lefts. He
could not describe the difference, to be sure, but he sees it well
enough for his purposes. If you ask an older person to describe this
difference, and rally him on his inability to do so, he is thus driven
to lay them side by side and study out the difference still more
precisely.

The average non-mechanical person, on acquiring an automobile, takes
it as a gift of the gods, a big total thing, simply to sit in and go.
He soon learns certain parts that he must deal with, but most of the
works remain a mystery to him. Then something goes wrong, and he gets
out to look. "What do you suppose this thing is here? I never noticed
it before". Tire trouble teaches him about wheels, engine trouble
leads him to know the engine, ignition trouble may lead him to notice
certain wires and binding-posts that were too inconspicuous at first
to attract his attention. A car becomes to him a thing with a hundred
well-known parts, instead of just one big totality.

Blocked response, closer examination, new stimulus isolated that gives
satisfactory response--such is, typically, the process of analytic
perception.

Sensory Data Serving as Signs of Various Sorts of Fact

Among facts perceived, we may list things and events, and their
qualities and relations. Under "things" we here include persons and
animals and everything that would ordinarily be called an "object".
Under "events", we include movement, change and happenings of all
sorts. Under {438} "qualities" we may include everything that can be
discovered in a thing or event taken by itself, and under "relations"
anything that can be discovered by comparing or contrasting two things
or events. The "groups" that we have se