or by association and habit, as is the case with the words of any
natural language, or the object-meanings which we attach to colors
and shapes. The poet does not work with sounds, but with words which
already have their definite meanings; his creation consists of the
larger whole into which he weaves them. Of course, even in the case
of ordinary verbal expression, the thought often comes first before
its clothing in words, when there is a certain process of choice and
fitting; and in painting there is always the possibility of varying
conventional forms; yet even so, in large measure, the elements of the
arts are themselves expressions, in which a unity of form and content
already exists.

In art, however, there are subtler aspects to the relation between
form and content, and these have a unique aesthetic significance. For
there, as we know, the elements of the medium, colors and lines and
sounds, and the patterns of these, their harmonies and structures and
rhythms, are expressive, in a vague way, of feeling; hence, when the
artist employs them as embodiments of his ideas, he has to select them,
not only as carriers of meaning, but as communications of mood. Now,
in order that his selection be appropriate, it is clearly necessary
that the feeling tone of the form be identical with that of the content
which he puts into it. The medium as such must reexpress and so enforce
the values of the content. This is the "harmony," as distinguished
from the mere unity, of form and content, the existence of which in
art is one of its distinguishing properties. I have already called
attention to this in our second chapter. It involves, as we observed,
that in painting, for example, the feeling tone of the colors and lines
should be identical with that of the objects to be represented; in
poetry, that the emotional quality of meter and rhythm should be attuned
to the incidents and sentiments expressed. Otherwise the effect is