prepare us for
understanding the main fact of all psychological aesthetics: namely
that the satisfaction or the dissatisfaction which we get from shapes
is satisfaction or dissatisfaction in what are, directly or indirectly,
activities of our own.

Etymologically and literally, _perception_ means the act of
_grasping_ or _taking_ in, and also the result of that action. But
when we thus _perceive_ a shape, what is it precisely that we grasp
or take in? At first it might seem to be the _sensations_ in which that
form is embodied. But a moment's reflection will show that this
cannot be the case, since the sensations are furnished us simply
without our performing any act of perception, thrust on us from
outside, and, unless our sensory apparatus and its correlated brain
centre were out of order, received by us passively, nilly willy, the
Man on the Hill being invaded by the sense of that blue, that lilac
and that russet exactly as he might have been invaded by the smell
of the hay in the fields below. No: what we grasp or take in thus
actively are not the sensations themselves, but the _relations_
between these sensations, and it is of these relations, more truly than
of the sensations themselves, that a shape is, in the most literal sense,
_made up._ And it is this _making up of shapes,_ this grasping or
taking in of their constituent relations, which is an active process on
our part, and one which we can either perform or not perform. When,
instead of merely _seeing_ a colour, we _look at_ a shape, our eye
ceases to be merely passive to the action of the various light-waves,
and becomes active, and active in a more or less complicated way;
turning its differently sensitive portions to meet or avoid the
stimulus, adjusting its focus like that of an opera glass, and like an
opera glass, turning it to the right or left, higher or lower.

Moreover, except in dealing with very small surfaces, our eye
moves about in our head and moves our head, and sometimes our
whole body, along with it. An analogous active process undoubtedly
distinguishes _listening_ from mere _hearing;_ and although
psycho-physiology seems still at a loss for the precise adjustments
of the inner ear corresponding to the minute adjustments of the eye,
it is generally recognised that auditive attention is accompanied by
adjustments of the vocal parts, or preparations for such adjustments,
which account for the impression of _following_ a sequence of
notes