eact by saying, "I smell a bear." This reaction,
like that of the horse, is merely closely similar on different occasions
where the environment affords instances of the same universal. Words
of which the logical meaning is universal can therefore be employed
correctly, without anything that could be called consciousness of
universals. Such consciousness in the only sense in which it can be
said to exist is a matter of reflective judgment consisting in the
observation of similarities and differences. A universal never appears
before the mind as a single object in the sort of way in which something
perceived appears. I THINK a logical argument could be produced to show
that universals are part of the structure of the world, but they are
an inferred part, not a part of our data. What exists in us consists of
various factors, some open to external observation, others only visible
to introspection. The factors open to external observation are primarily
habits, having the peculiarity that very similar reactions are produced
by stimuli which are in many respects very different from each other. Of
this the reaction of the horse to the smell of the bear is an instance,
and so is the reaction of the man who says "bear" under the same
circumstances. The verbal reaction is, of course, the most important
from the point of view of what may be called knowledge of universals. A
man who can always use the word "dog" when he sees a dog may be said,
in a certain sense, to know the meaning of the word "dog," and IN THAT
SENSE to have knowledge of the universal "dog." But there is, of course,
a further stage reached by the logician in which he not merely reacts
with the word "dog," but sets to work to discover what it is in the
environment that causes in him this almost identical reaction on
different occasions. This further stage consists in knowledge of
similarities and differences: similarities which are necessary to the
applicability of the word "dog," and differences which are compatible
with it. Our knowledge of these similarities and differences is never
exhaustive, and therefore our knowledge of the meaning of a universal is
never complete.

In addition to external observable habits (including the habit of
words), there is also the generic image produced by the superposition,
or, in Semon's phrase, homophony, of a number of similar perceptions.
This image is vague so long as the multiplicity of its prototypes is not
recognized, but