er to become acquainted with those
which particularly interest him, partly to develop himself in more
directions, partly to understand better that which concerns him; we
shall add a few further remarks on this significant point.

Up to the present the painter has been able merely to wonder at the
physicist's theory of colors, without gaining any advantage from it.
The natural feeling of the artist, however, constant training, and a
practical necessity led him into a way of his own. He felt the vivid
contrasts out of the union of which harmony of color arises, he
designated certain characteristics through approximate sensations, he
had warm and cold colors, colors which express proximity, others which
express distance, and what not; and thus in his own way he brought
these phenomena closer to the most general laws of Nature. Perhaps the
supposition is confirmed that the operations of Nature in colors, as
well as magnetic, electric, and other operations, depend upon a mutual
relation, a polarity, or whatever else we might call the twofold or
manifold aspects of a distinct unity.

We shall make it our duty to present this matter in detail and in a
form comprehensible to the artist; and we can be the more hopeful of
doing something welcome to him, since we shall be concerned only with
explaining and tracing to fundamental principles things which he has
hitherto done by instinct.

So much for what we hope to impart in regard to Nature; now for what
is most necessary in regard to Art.

Since the arrangement of this work proposes the presentation of single
treatises, some of these only in part, and since it is not our desire
to dissect a whole, but rather to build up a whole from many parts,
it will be necessary to present, as soon as possible and in a general
summary, those thing's which the reader will gradually find unfolded
in our detailed elaborations. We shall, therefore, be occupied first
with an essay on plastic art, in which the familiar rubrics will be
presented according to our interpretation and method. Here it will be
our main concern to emphasize the importance of every branch of Art,
and to show that the artist must not neglect a single one, as has
unfortunately often happened, and still happens.

Hitherto we have regarded Nature as the treasure chamber of material
in general; now, however, we reach the important point where it is
shown how Art prepares its materials for itself.

When the artist takes any