— Flaubert, Correspondance, éd. Conard, II, 348; III, 219Voltaire made, with this novel, a résumé of all his works ... His whole intelligence was a war machine. And what makes me cherish it is the disgust which has been inspired in me by the Voltairians, people who laugh about the important things! Was he laughing? Voltaire? He was screeching ...
— Flaubert, Correspondance, éd. Conard, II, 348; III, 219
Though Voltaire did not openly admit to having written the controversial Candide until 1768 (until then he signed with a pseudonym: "Monsieur le docteur Ralph", or "Doctor Ralph"), his authorship of the work was hardly disputed.[a]
Immediately after publication, the work and its author were denounced by both secular and religious authorities, because the book openly derides government and church alike. It was because of such polemics that Omer-Louis-François Joly de Fleury, who was Advocate General to the Parisian parliament when Candide was published, found parts of Candide to be "contrary to religion and morals".
Despite much official indictment, soon after its publication, Candide's irreverent prose was being quoted. "Let us eat a Jesuit", for instance, became a popular phrase for its reference to a humorous passage in Candide. By the end of February 1759, the Grand Council of Geneva and the administrators of Paris had banned Candide. Candide nevertheless succeeded in selling twenty thousand to thirty thousand copies by the end of the year in over twenty editions, making it a best seller. The Duke de La Vallière speculated near the end of January 1759 that Candide might have been the fastest-selling book ever. In 1762, Candide was listed in the Index Librorum Prohibitorum, the Roman Catholic Church's list of prohibited books.
Bannings of Candide lasted into the twentieth century in the United States, where it has long been considered a seminal work of Western literature. At least once, Candide was temporarily barred from entering America: in February 1929, a US customs official in Boston prevented a number of copies of the book, deemed "obscene", from reaching a Harvard University French class. Candide was admitted in August of the same year; however by that time the class was over. In an interview soon after Candide's detention, the official who confiscated the book explained the office's decision to ban it, "But about 'Candide,' I'll tell you. For years we've been letting that book get by. There were so many different editions, all sizes and kinds, some illustrated and some plain, that we figured the book must be all right. Then one of us happened to read it. It's a filthy book".