The common identity of the arts was a master theory of Richard Wagner, which he attempted to put into practice.  Walter Pater in his essay on The School of Giorgione has dwelt upon the same theme, declaring music the archetype of the arts.  In his Essays Speculative John Addington Symonds said some pertinent things on this subject.  Camille Mauclair in his Idees Vivantes proposes in all seriousness a scheme for the fusion of the seven arts, though he deplored Wagner’s efforts to reach a solution.  Mauclair’s theory is that the fusion can only be a cerebral one, that actually mingling sculpture, architecture, music, drama, acting, colour, dancing can never evoke the sensation of unity.  Synthesis is not thus to be attained.  It must be in the idea of the arts rather than their material realisation.  A pretty chimera!  Yet one that has piqued the world of art in almost every century.  It was the half-crazy E.T.W.  Hoffmann, composer, dramatist, painter, poet, stage manager, and a dozen other professions, including that of genius and drunkard, who set off a train of ideas which buzzed in the brains of Poe, Baudelaire, and the symbolists.  People who hear painting, see music, enjoy odorous poems, taste symphonies, and write perfumes are now classed by the omnipotent psychical police as decadents, though such notions are as old as literature.  Suarez de Mendoza in his L’Audition Coloree has said that the sensation of colour hearing, the faculty of associating tones and colours, is often a consequence of an association of ideas established in youth.  The coloured vowels of Arthur Rimbaud, which must be taken as a poet’s crazy prank; the elaborate treatises by Rene Ghil, which are terribly earnest; the remarks that one often hears, such as “scarlet is like a trumpet blast”; certain pages of Huysmans, all furnish examples of this curious muddling of the senses and mixing of genres.  Naturally, it has invaded criticism, which, limited in imagery, sometimes seeks to transfer the technical terms of one art to another.

Whistler with his nocturnes, notes, symphonies in rose and silver, his colour-sonatas, boldly annexed well-worn musical phrases, that in their new estate took on fresher meanings even if remaining knee-deep in the kingdom of the nebulous.  It must be confessed modern composers have retaliated.  Musical impressionism is having its vogue, while poets are desperately pictorial.  Soul landscapes and etched sonnets are not unpleasing to the ear.  What if they do not mean much?  There was a time when to say a “sweet voice” would arouse a smile.  What has sugar to do with sound?  It may be erratic symbolism, this confusing of terminologies; yet, once in a while, it strikes sparks.  There is a deeply rooted feeling in us that the arts have a common matrix, that they are emotionally akin.  “Her slow smile” in fiction has had marked success with young people, but a “slow landscape” is still regarded suspiciously.  The bravest critic of art was Huysmans.  He pitched pell-mell into the hell-broth of his criticism any image that assaulted his fecund brain.  He forced one to see his picture—­for he was primarily concerned not with the ear, but the eye.