In 1755, Winckelmann published Reflections on the Imitation of Greek Art. The following year, Burke published his Inquiry into the Origins of the Sublime. These two theorists represented contemporary vanguards in a debate over the proper aims and subject of art: the neo-classical vs. the Romantic.
For Winckelmann, "art should aim at noble simplicity and calm grandeur." It should pursue quiet contemplation of perfect forms of beauty. The Romanticists sought art that was emotionally charged, even reverent of frightening, untamable forces: "the ideas of pain and danger, that is to say whatever is in any sort terrible, is a source of the sublime." [Burke] These two approaches might be termed "religion as art" and "art as religion."
In the Preface to "Cromwell" (known as the "Manifesto of Romanticism"), Victor Hugo claims that the age had evolved a new principle--"the grotesque"--and thereby given birth to "a new form of the art [comedy]." This new sensibility would famously find expression in Hugo's "Hunchback of Notre Dame" and "The Man Who Laughs" (an early ancestor of Batman's Joker). Yet the Romantic movement was so prolonged and multi-faceted that debate over its meaning still persists.
Hugo's Preface to "Cromwell":