The most profound of the sensationalists of this time was Condillac (1715–1780),[50] who does not, however, appear to be connected with the _Encyclopædia_. He published his _Treatise on Sensations_ in 1754, which reduced Locke’s psychological analysis to a pure sensationalism. The well-known figurative statue endowed only with the sense of smell was conceived by him. He introduced Locke’s psychology into France, whence it was carried into Germany. =The Social Enlightenment= (1762–1789). The second period of the French Enlightenment begins with the publication of Rousseau’s _Contrat Social_ in 1762 and culminates in the Revolution. The influence of Rousseau dominates the second period as that of Voltaire dominated the first. Voltaire had never aimed at a social revolution. His objective point was to reinstate the understanding, to emancipate the individual by self-culture and by freedom of thought. He was not historian enough to see that he could not revolutionize intellectual France without pulling down the social structure. He did not realize that in striking at the tyranny of the church he was dealing a fatal blow at the structure of French society. The literary fencing between Voltaire and the adroit churchmen might have been amusing, had the issue not been so serious. But although superficial and vain, Voltaire was downright in earnest. At one time it seemed as if the intellectual Enlightenment would work itself out in the church. But the causes of the revolt were too deeply social, the malady against which Voltaire was aiming was too vital; and besides, at that moment attention was being directed to the character of the State itself. =Rousseau= (1712–1778).[51] Rousseau began at the point where Voltaire left off. He was under the influence of Voltaire at the first and received from Voltaire his original productive impulse. But the concrete right of individuals, and not their abstract intellectual freedom, was what appealed to Rousseau. Strict moderation and literary freedom were too negative, half-hearted, for a reformer of Rousseau’s type. Public opinion was not to be found in Versailles, as Voltaire thought, but in the streets of Paris. The Revolution then came to a head, and we find the schools of Voltaire and Rousseau locking horns. Voltaire’s theory of moderation was represented in the Constituent Assembly and the upper and middle classes, while Rousseau’s radicalism was introduced in the Convention and fully expounded in the sections of the Commune of Paris which attacked the Convention. History shows how impossible the aim of each school was, and how the contest had to be fought over again in the nineteenth century.