and mingle and become one. Above all embodiment in
matter, there is a plane on which I feel my community with the
world external to me, recognizing that world to be an extension of
my own personality, a plane on which I can identify myself with the
thing outside of me in so far as it is the expression of what I am or
may become. Between me and the external world there is a common
term. The effect which nature has upon us is determined, not by the
object itself alone and not by our individual mind and temperament
alone, but by the meeting of the two, the community between the
object and the spirit of man. When we find nature significant and
expressive, it is because we make nature in some way a part of our
own experience.

The material of an object is perceived by the senses. We see that it is
blue or green or brown; we may touch it and note that it is rough or
smooth, hard or soft, warm or cold. But the expressiveness of the
object, its value for the emotions, does not stop with its merely
material qualities, but comes with our grasp of the "relations" which
it embodies; and these relations, transmitted through material by the
senses, are apprehended by the mind. There are, of course,
elementary data of sense-perception, such as color and sound. It may
be that I prefer red to yellow because my eye is so constituted as to
function harmoniously with a rate of vibration represented by 450
billions per second, and discordantly with a rate of vibration
represented by 526 billions per second. So also with tones of a given
pitch. But though simple color and simple sound have each the
power to please the senses, yet in actual experience neither color nor
sound is perceived abstractly, apart from its embodiment in form.
Color is felt as the property of some concrete object, as the crimson
of a rose, the dye of some fabric or garment, the blue of the sky,
which, though we know it to be the infinite extension of atmosphere
and ether, we nevertheless conceive as a dome, with curvature and
the definite boundary of the horizon. Sound in and of itself has pitch
and _timbre_, qualities of pure sensation; but even with the
perception of sound the element of form enters in, for we hear it
with a consciousness of its duration--long or short--or of its relation
to other sounds, heard or imagined.

Our perceptions, therefore, give us forms. Now form implies
_relation,_ the reference of one part to the other parts in the
composition of t