For some years Voltaire led a migratory existence, but he finally settled in 1758 at Ferney, where he spent the remaining 20 years of his life. In the interval between his return from Berlin and his establishment at Ferney, he completed his most ambitious work, the Essai sur l'histoire générale et sur les moeurs et l'esprit des nations (Essay on General History and on the Customs and the Character of Nations, 1756). In this work, a study of human progress, Voltaire decries supernaturalism and denounces religion and the power of the clergy, although he makes evident his own belief in the existence of God.
After settling in Ferney, Voltaire wrote several philosophical poems, such as Le
désastre de Lisbonne (The Lisbon Disaster, 1756); a number of satirical and
philosophical novels, of which the most brilliant is Candide (1759); the tragedy Tancrède
(1760); and the Dictionnaire philosophique (1764). Feeling secure in his
sequestered retreat, he sent forth hundreds of short squibs and broadsides satirizing
abuses that he desired to expose. Those who suffered persecution because of their beliefs
found in Voltaire an eloquent and powerful defender. The flavor of Voltaire's activities
could be summarized in the phrase he often used: écrasons l'infâme ("let us
crush the infamous one"). With this phrase, he referred to any form of religion that
persecutes nonadherents or that constitutes fanaticism. For Christianity he would
substitute deism, a purely rational religion. Candide, in which Voltaire analyzes
the problem of evil in the world, depicts the woes heaped upon the world in the name of
religion. He died in Paris, May 30, 1778.