or there, neither Newfoundland, nor Retriever,
nor Terrier, nor Greyhound, nor Pug, nor Bulldog. The concept consists
only of the attributes common to all dogs apart from any that are
peculiar to any variety or any individual. Now we cannot form any such
conceptual image. Our conceptual image is always of some definite
size and shape. Therefore, it is argued, we cannot conceive what a dog
means, and dogs have nothing in common but the name. This, however,
does not follow. The concept is not the conceptual image, and
forming the image is not conception. We may even, as in the case of
a chiliagon, or thousand-sided figure, conceive the meaning without
being able to form any definite image.

How then, do we ordinarily proceed in conceiving, if we cannot picture
the common attributes alone and apart from particulars? We attend, or
strive to attend, only to those aspects of an image which it has in
common with the individual things denoted. And if we want to make our
conception definite, we pass in review an indefinite number of the
individuals, case after case.

A minor psychological question concerns the nature of the conceptual
image. Is it a copy of some particular impression, or a confused blur
or blend of many? Possibly neither: possibly it is something like
one of Mr. Galton's composite photographs, photographs produced by
exposing the same surface to the impressions of a number of different
photographs in succession. If the individuals are nearly alike,
the result is an image that is not an exact copy of any one of the
components and yet is perfectly distinct. Possibly the image that
comes into our mind's eye when we hear such a word as "horse" or "man"
is of this character, the result of the impressions of a number of
similar things, but not identical with any one. As, however, different
persons have different conceptual images of the same concept, so we
may have different conceptual images at different times. It is only
the concept that remains the same.

But how, it may be asked, can the concept remain the same? If the
universal or concept psychologically is an intellectual act, repeated
every time we conceive, what guarantee have we for the permanence
of the concept? Does this theory not do away with all possibility of
defining and fixing concepts?

This brings us back to the doctrine already laid down about the truth
of Realism. The theory of the concept is not exhausted when it is
viewed only psychological