they are tolerated and enriched." Telushkin states that Voltaire did not limit his attack to aspects of Judaism that Christianity used as a foundation, repeatedly making it clear that he despised Jews. On the other hand, Peter Gay, a contemporary authority on the Enlightenment, also points to Voltaire's remarks (for instance, that the Jews were more tolerant than the Christians) in the Traité sur la tolérance and surmises that "Voltaire struck at the Jews to strike at Christianity". Whatever anti-semitism Voltaire may have felt, Gay suggests, derived from negative personal experience. Arthur Hertzberg, a Conservative Rabbi, claims that Gay's second suggestion is also untenable, as Voltaire himself denied its validity when he remarked that he had "forgotten about much larger bankruptcies through Christians". However, Bertram Schwarzbach's far more detailed studies of Voltaire's dealings with Jewish people throughout his life concluded that he was anti-biblical, not anti-semitic. His remarks on the Jews and their "superstitions" were essentially no different from his remarks on Christians. Some authors link Voltaire's anti-Judaism to his polygenism. According to Joxe Azurmendi this anti-Judaism has a relative importance in Voltaire's philosophy of history. However, Voltaire's anti-Judaism influenced later authors like Ernest Renan. Voltaire did have a Jewish friend, Daniel de Fonseca, whom he esteemed highly, and proclaimed him as "the only philosopher, perhaps, among the Jews of his time". Voltaire had also condemned the persecution of Jews on several occasions including in his work Henriade, and never advocated violence or attacks against them. According to the historian Will Durant, Voltaire had praised the simplicity, sobriety, regularity, and industry of Jews, however subsequently, Voltaire became strongly anti-Semitic after some regrettable personal financial transactions and quarrels with Jewish financiers. In his Essai sur les moeurs Voltaire had denounced the ancient Hebrews using strong language; a Catholic priest had protested against this censure. The anti-Semitic passages in Voltaire's Dictionnaire philosophique were criticized by Isaac De Pinto in 1762. Subsequently, Voltaire agreed with the criticism of the anti-Semitic passages and stated that De Pinto's letter convinced that there are "highly intelligent and cultivated people" among the Jews and that he had been "wrong to attribute to a whole nation the vices of some individuals"; he also promised to revise the objectionable passages for forthcoming editions of the Dictionnaire philosophique, but failed to do so. Islam Voltaire's views about Islam were generally negative, and he found its holy book, the Quran, to