l chiefly have reference, first, to plastic art; then, to
art in general; finally, to the general training of the artist.

The highest demand that is made on an artist is this: that he be
true to Nature, study her, imitate her, and produce something that
resembles her phenomena. How great, how enormous, this demand is,
is not always kept in mind; and the true artist himself learns it by
experience only, in the course of his progressive development. Nature
is separated from Art by an enormous chasm, which genius itself is
unable to bridge without external assistance.

All that we perceive around us is merely raw material; if it happens
rarely enough that an artist, through instinct and taste, through
practice and experiment, reaches the point of attaining the beautiful
exterior of things, of selecting the best from the good before him,
and of producing at least an agreeable appearance, it is still more
rare, particularly in modern times, for an artist to penetrate into
the depths of things as well as into the depths of his own soul,
in order to produce in his works not only something light and
superficially effective, but, as a rival of Nature, to produce
something spiritually organic, and to give his work of art a content
and a form through which it appears both natural and beyond Nature.

Man is the highest, the characteristic subject of plastic art;
to understand him, to extricate oneself from the labyrinth of his
anatomy, a general knowledge of organic nature is imperative. The
artist should also acquaint himself theoretically with inorganic
bodies and with the general operations of Nature, particularly if, as
in the case of sound and color, they are adaptable to the purposes
of art; but what a circuitous path he would be obliged to take if
he wanted to seek laboriously in the schools of the anatomist, the
naturalist, and the physicist, for that which serves his purposes! It
is, indeed, a question whether he would find there what must be most
important for him. Those men have the entirely different needs of
their own pupils to satisfy, so that they cannot be expected to think
of the limited and special needs of the artist. For that reason it is
our intention to take a hand, and, even though we cannot see prospects
of completing the necessary work ourselves, both to give a view of the
whole and to begin the elaboration of details.

The human figure cannot be understood merely through observation
of its surface; th