The theory of art has to solve this difficulty. As for its interest, on the practical side of art, we shall do well to pass it wholly by. We may formulate principles as we please for mediocrity and the talents that express it, the result is always the same. Whether our theory is a distorted one or unexceptionable all we shall get is something commonplace or weak. At the same time Art and more particularly painting has unquestionably received a stimulus other than that we have deprecated from this very quest of so-called Ideals; and, through the renewed interest thereby excited in old Italian and German painters, has at least made an effort to secure a profounder and more vital content in its work. The world is quite as tired of hearing the praises of that equally exclusive Ideal in the opposite camp, namely, that of undiluted realism in art. Theatregoers are, to take an example close at hand, heartily sick of the realistic type of domestic drama. The old story over and over again--disputes between husband and wife, sons and daughters, the source of our income, the inventory of our expenses, the servility of ministers and the intrigues of their lackeys and secretaries, down to the question of the last sixpence between the dame of the house and her kitchen-maid, or up to the last gossip of the daughters over their touching love-affairs in the parlour--such tales of woe most of us will prefer to take where, we may at least get them without adulteration--at home. In this opposition between Ideal and Nature writers have been inclined to regard one type of art to the exclusion of others, with an especial predilection, however, for painting, whose subject-matter is the particularity of sense-perception. We will test our problem by putting the question to start with wholly in general terms, thus: "Is art to be prose or poetry?" Now what is truly poetical in art is just that which we have called the Ideal. If the question of difficulty in question is a mere matter of terminology we are quite prepared to call the Ideal something else. But, however called, the question remains what it is which constitutes poetry or prose in art. And although the adherence to what is in itself poetical in the determination of it by certain crafts may lead those arts into confusion, and, indeed, has already done so, it is contended that in so far as any subject has an express affinity with poetry, such has been also the subject of genuine pictorial treatment, genuine for the simple reason that such a content is unquestionably of a true poetical nature.