To give to his material the semblance of the body beautiful is the technical problem of the sculptor. Although this semblance is primarily for sight, it is not exclusively so. For in sculpture shape is not two-dimensional, but plastic; and for the full appreciation of plasticity, the cooperation of touch is required. Moreover, not only the perception of the form, but also a large part of the appreciation of the charm of the body depends upon touch. Of course we do not ordinarily touch statues, but they should make us want to touch them, and we should touch them--in the imagination. The surfaces of the statue should therefore be so modeled as to give us, in the imagination, the pleasures that we get when we touch the living body. It is well known that these touch values were destroyed by the neo-classicists when they polished the surfaces of their statues. Such sculpture for the eye only is almost as good when reproduced in an engraving that preserves its visual quality, and is therefore lacking in complete sculptural beauty. But no plane reproduction can replace the best Greek, Italian, or French work. The life of the statue should, however, be more than skin deep. We should appreciate it through sensations of motion and strain as well as through sight and touch, feeling the tenseness or relaxation of the muscles and tendons beneath. We should move with its motion or rest with its repose. And this does not mean that we should merely know that an attitude of quiet or of motion is represented; we should actually experience quiet or motion. In our own bodies sensations corresponding to these should be awakened by the visual image of the statue, yet should be fused with the latter, becoming for our perception its, not ours, in accordance with the mechanism of _einfuhlung_ described in our fourth chapter. The light rhythmic motion of the figures in Carpeaux's "Dance" should thrill in our own limbs, yet seem to thrill in theirs.