The arts imitative of nature--The arts classified according to the character of their signs--Poetry not a compound art, primarily--The extent to which the arts may improve upon nature. Since art uses natural signs for the purpose of representing nature, it is necessarily mimetic in character.[19] Poetry represents all that the other arts imitate, and in addition, presumed divine actions. Specially it imitates human and presumed spiritual actions, with form and expression; expression directly, form indirectly. Sculpture imitates human and presumed spiritual form and expression; form directly, expression indirectly. It also represents animal forms, and modifications of natural forms in ornament. Painting imitates natural forms and products, and specially human form and expression; form directly, expression indirectly. Fiction imitates human actions, and form and expression; expression directly, form indirectly. Music imitates natural sounds and combines them and specially represents human emotional effects. Architecture is the least imitative of the arts, its freedom in the representation of nature being restricted by the necessity of serving the end of utility. It combines geometrical forms, and in the positions and proportions of these, is compelled to represent what we understand from experience of nature as natural balance. The poet may give to a character sublime attributes far above experience, or expand form as Homer raises the stature of Strife to the heavens, but he cannot provide attributes beyond experience in kind, or any part of a form outside of nature. He may combine or rearrange, and enlarge or diminish as he will, and so may the painter, the sculptor, or musician, but he is powerless to create signs unknown to nature. It follows then, that he who imitates nature in the most beautiful way, that is to say, he who combines the signs of nature to form the most beautiful whole, produces the greatest work of art. It would appear that upon the character of their principal signs is dependent the relative position of the arts in respect of the recognition of beauty therein. Of the six fine arts, namely, Poetry, Sculpture, Painting, Fiction, Music, and Architecture, the first four, which hereafter in this work will be known as the Associated Arts, have for their principal sign the human figure, to which everything else is subordinate; while in music the signs consist of tones, and in architecture, of lines.