THE range of emotions which Ruskin admitted into "fine art" was limited by moral prejudices. But his use of the term moral had a special significance that no mere description of "proper emotion" or "respectable feelings" can entirely convey. In a profound sense beauty was emotional; and because all emotions were supposed to fall under a moral faculty, beauty was moral. Yet art held many kinds of ideas: like nature, art was a spiritual treasury; it was the greatest human record of virtues. A moment's reflection upon the traditions which formed Ruskin's inheritance will illuminate the fact that in discussing ideas, content and subject matter he was following a conventional road of esthetic speculation.
The popular subjects of art had been religious. Slowly, they had changed to portraiture, to classic themes, to historical allegory and, shortly before Ruskin's time, to natural landscape. Each of these changes brought some new theoretical justification, some eager attempt to make taste reasonable. A sanction had to be given to things that had less sanction than religious subject matter. So the attempted justification of each new province of beauty pushed criticism into religion, religion into morals, morals into esthetics, and esthetics, if the nineteenth century writer were sufficiently sophisticated, into German metaphysics.