Art is not, as the metaphysicians say, the manifestation of some mysterious Idea of beauty or God; it is not, as the aesthetical physiologists say, [play or] a game in which one releases surplus energy, ...not the production of pleasing objects, and is above all, not pleasure itself, but it is the means of union among mankind, joining them in the same feelings, and necessary for the life and progress toward the good of the individual and of humanity.