Now with reference to the purpose of art to express in a given material, there are, I think, a few general principles of judgment applying to all the arts, implicitly or explicitly recognized in criticism, and capable of formulation. First, the complete use of the medium. We prefer, other things being equal, the work of art that has fully exploited the expressive possibilities of its medium to one that has failed to do so. As an illustration, I would cite the almost universal condemnation, at the present time, of neo-classical sculpture, in which the touch values of the surfaces of statues were destroyed. Of course some compensating gain may be claimed--a greater visual purity; yet, as we shall see, from the point of view of expression, the gain was negligible compared with the loss. So likewise, unless the _vers-libristes_ can show some positive gain in expression,--a power to do something that normal verse cannot do, their work must rank lower than normal verse, which makes fuller use of the rhythmic possibilities of language. Second, the unique use of the material. What we want of art depends, not only on comparison between works of art belonging to the same genre, but on comparison of the purposes of different genres, indeed of the different arts themselves. What we want of painting depends upon what we want of sculpture; what we want of poetry depends upon what we want of painting and music. We compare picture with picture; but equally we compare picture with statue and poem. We do not want the sculptor to try to do what the painter can do better, and vice-versa; or the poet to encroach on the domains proper to the musician and painter. We do not want poetry to be merely imagistic or merely musical when we have another art that can give us much better pictures and still another that can give us much better music than any word-painting or word-music. When we read a poem, we do not want to be made to think how much better the same thing could be done in a different medium. There is nothing so salutary in keeping an art to its proper task as a flourishing condition of the other arts. Here the great example is France, where the limitations of the different arts have been best recognized all the while the highest level of perfection has been reached in many arts contemporaneously.