If Voltaire belonged to the eighteenth century, and brought to a brilliant focus its scattered rays, Rousseau belonged more to the nineteenth. Amidst the _persiflage_, the mockery, the light and easy philosophy, of his day, he stood, "among them, but not of them, in a crowd of thoughts which were not their thoughts." This is the true explanation of his weakness and strength, and of the intense dislike felt for him by Voltaire and the school of Voltaire. They belonged to their time, Rousseau to a coming time. The eighteenth century, especially in France, was one in which nature was at its minimum and art at its maximum. All was art. But art separated from nature becomes artificial, not to say artful. Decorum was the law in morals; the _bienséances_ and _convenances_ ruled in society. The stage was bound by conventional rules. Poetry walked in silk attire, and made its toilette with the elaborate dignity of the _levée_ of the Grand Monarque. Against all this Rousseau led the reaction--the reaction inevitable as destiny. As art had been pushed to an extreme, so now naturalism was carried to the opposite extreme. Rousseau was the apostle of nature in all things. Children were to be educated by the methods of nature, not according to the routine of old custom. Governments were to go back to their origin in human nature; society was to be reorganized on first principles. This voice crying in the wilderness was like the trumpet of doom to the age, announcing the age to come. It laid the axe at the root of the tree. Its outcome was the French Revolution, that rushing, mighty flood, which carried away the throne, the aristocracy, the manners, laws, and prejudices of the past. In his first great work, the work which startled Europe, Rousseau recalled man to himself. He said, "The true philosophy is to commune with one's self,"--the greatest saying, thinks Henri Martin, that had been pronounced in that century. Rousseau condemned luxury, and uttered a prophetic cry of woe over the tangled perplexities of the time. "There is no longer a remedy, _unless through some great revolution, almost as much to be feared as the evil it would cure,--which it is blamable to desire, impossible to foresee_."