or in part, it obviously became
very advantageous to every animal to develope an organ sensitive
to these vibrations -- sensitive, that is, to light. For this would give
the mind instantaneous impressions dependent upon the presence
and nature of distant objects.

To this circumstance we must attribute the primacy of sight in our
perception, a primacy that makes light the natural symbol of
knowledge. When the time came for our intelligence to take the
great metaphysical leap, and conceive its content as permanent and
independent, or, in other words, to imagine _things,_ the idea of
these _things_ had to be constructed out of the materials already
present to the mind. But the fittest material for such construction
was that furnished by the eye, since it is the eye that brings us into
widest relations with our actual environment, and gives us the
quickest warning of approaching impressions. Sight has a
prophetic function. We are less interested in it for itself than for the
suggestion it brings of what may follow after. Sight is a method of
presenting psychically what is practically absent; and as the
essence of the _thing_ is its existence in our absence, the _thing_ is
spontaneously conceived in terms of sight.

Sight is, therefore, perception _par excellence,_ since we become
most easily aware of objects through visual agency and in visual
terms. Now, as the values of perception are those we call aesthetic,
and there could be no beauty if there was no conception of
independent objects, we may expect to find beauty derived mainly
from the pleasures of sight. And, in fact, form, which is almost a
synonym of beauty, is for us usually something visible: it is a
synthesis of the seen. But prior to the effect of form, which arises
in the constructive imagination, comes the effect of colour; this is
purely sensuous, and no better intrinsically than the effects of any
other sense: but being more involved in the perception of objects
than are the rest, it becomes more readily an element of beauty.

The values of colours differ appreciably and have analogy to the
differing values of other sensations. As sweet or pungent smells, as
high and low notes, or major and minor chords, differ from each
other by virtue of their different stimulation of the senses, so also
red differs from green, and green from violet. There is a nervous
process for each, and consequently a specific value. This emotional
quality has affinity to the emo