Rousseau's "heart," Voltaire complained, could justify him in anything. Guided by the "inner voice" of conscience, a man could do as he pleased. From the murderous and adulterous David, in the Old Testament, to any number of latter-day tyrants, Voltaire lamented, history was strewn with icy campaigners who had learned to manage the accusing conscience to expert degree. "There is a natural law," he declared rather plaintively in his Philosophical Dictionary, "but it is still more natural to many people to forget it."
The sin of religious "fanaticism" was to subordinate conscience to the "passions" - under the dangerous delusion that my desire represents God's will. The problem with religion - even in its more acceptable formulations - is that it too often flattered, rather than stirred, the slumbering conscience. The moralizing philosopher defined his task in self-consciously homiletic terms: "it is judicious to endeavor to awaken conscience both in mantua-makers and in monarchs." Indeed, "it is necessary to preach better than modern preachers usually do, who seldom talk effectively to either." Enlightenment was again strangely evangelical.
