perceive the shape of objects at a little distance. Touch and
smell, hearing, sight; such is sequence of sense perceptions. The
sense-organs respond to continually more delicate and subtle
impacts, and cover an ever-widening range of more and more distant
objects. Up to this point intelligence has hardly included more than
sense-perceptions.

But these sense-perceptions have been all the time spurring the mind
to begin a higher work. At first it is conscious merely of objects,
and its main effort is to gain a clearer and clearer perception of
these.

Now it is led to undertake, so to speak, the work of a sense-organ
of a higher grade. It begins to directly see invisible relations
just as truly as through the eye it has perceived light. First
perhaps it perceives that certain perceptions and experiences,
agreeable or disagreeable, occur in a certain sequence. It begins to
associate these. It learns thus to recognize the premonitory
symptoms of nature's favor or disfavor, and thus gains food or
avoids dangers. The bee learns to associate accessible nectar with a
certain spot on the flower marked by bright dots or lines,
"honey-guides," and the chimpanzee that when a hen cackles there is
an egg in the nest. But association is only the first lesson;
inference and understanding follow.

The child at kindergarten receives a few blocks. It admires and
plays with them. Then it is taught to notice their form. After a
time it arranges them in groups and learns the first elements of
number. But when it has advanced to higher mathematics, the blocks,
or figures on the blackboard, become only symbols or means of
illustrating the great theorems and propositions of that science.
Thus the animal has begun in the kindergarten way to dimly perceive
that there are real, though intangible and invisible, relations
between objects. But what is all human science but the clearer
vision, and farther search into, and tracing of these same
relations? And what is all advance of knowledge but a perception of
ever subtler relations? What is even the knowledge of right but the
perception of the subtlest and deepest and widest relations of man
to his environment? The animal seems to be steadily advancing along
the path toward the perception of abstract truth, though man alone
really attains it.

And the higher power of association and inference which we call
understanding, aided by memory, results in the power of learning by
experience, so char