y present to the senses would mean much more; but
our thinking must go far beyond the present, and likewise far beyond
individual objects. It must be able to annihilate both time and space,
and to deal with millions of individuals together in one group or class.
Only in this way can our thinking go beyond that of the lower animals;
for a wise rat, even, may come to see the relation between a trap and
danger, or a horse the relation between pulling with his teeth at the
piece of string on the gate latch, and securing his liberty.

But it takes the farther-reaching mind of man to _invent_ the trap and
the latch. Perception alone does not go far enough. It is limited to
immediately present objects and their most obvious relations. The
perceptual image is likewise subject to similar limitations. While it
enables us to dispense with the immediate presence of the object, yet it
deals with separate individuals; and the world is too full of individual
objects for us to deal with them separately. It is in _conception_,
_judgment_, and _reasoning_ that true thinking takes place. Our next
purpose will therefore be to study these somewhat more closely, and see
how they combine in our thinking.

4. THE CONCEPT

Fortunately for our thinking, the great external world, with its
millions upon millions of individual objects, is so ordered that these
objects can be grouped into comparatively few great classes; and for
many purposes we can deal with the class as a whole instead of with the
separate individuals of the class. Thus there are an infinite number of
individual objects in the world which are composed of _matter_. Yet all
these myriads of individuals may be classed under the two great heads of
_inanimate_ and _animate_. Taking one of these again: all animate forms
may be classed as either _plants_ or _animals_. And these classes may
again be subdivided indefinitely. Animals include mammals, birds,
reptiles, insects, mollusks, and many other classes besides, each class
of which may be still further separated into its _orders_, _families_,
_genera_, _species_, and _individuals_. This arrangement economizes our
thinking by allowing us to think in large terms.

THE CONCEPTS SERVE TO GROUP AND CLASSIFY.--But the somewhat complicated
form of classification just described did not come to man ready-made.
Someone had to _see_ the relationship existing among the myriads of
animals of a certain class, and group these together under the