When Voltaire first crossed paths with the journalist-critic Abbé Pierre-François Guyot Desfontaines in the 1720s, the encounter seemed almost charitable: Voltaire used his influence to spring the abbé from Bicêtre prison (where he had been held on charges of sodomy) and to have a banishment order lifted so Desfontaines could return to Paris. But gratitude soon curdled. In his periodical Observations sur les écrits modernes, Desfontaines asserted a critic’s right to dissect Voltaire’s work, and the ever-sensitive philosophe reacted with wounded indignation. The simmering resentment meant that when Voltaire’s Éléments de la philosophie de Newton appeared in 1738—championing Newtonian empiricism over the long-entrenched Cartesian rationalism—Desfontaines seized the book as fresh ammunition in their feud.
Voltaire counter-attacked that November with a hastily printed rejoinder titled Le Préservatif, accusing Desfontaines of malice and ingratitude. Less than a month later, on 12 December 1738, Desfontaines fired back with La Voltairomanie, ou Lettre d’un jeune avocat. Issued anonymously by the Paris printer Chaubert to evade censorship, the 48-page pamphlet framed itself as a legal “mémoire” exposing Voltaire’s alleged vanity, opportunism and moral turpitude. Sold for a modest price and small enough to pass hand-to-hand, it was viciously personal—“perhaps the most sustained defamation Voltaire ever suffered,” according to modern scholars—and reportedly moved two thousand copies in its first fortnight.
The blast hit its target. At the château de Cirey, Voltaire was so shaken that he fainted twice, raged, then took to bed with fever; during January 1739 alone he penned thirty-eight letters about the affair, sued Desfontaines, lobbied ministers and even tried to have his adversary arrested. Paris’s lieutenant-general of police René Hérault finally imposed a ritual peace, forcing both men to sign formal retractions of their anonymous libels. Yet neither forgave nor forgot: Voltaire henceforth referred to Desfontaines as il buggerone abbate, while the abbé’s notoriety endured largely thanks to this very quarrel. La Voltairomanie thus stands as a textbook example of the combative literary culture of the early Enlightenment, where personal vendettas, philosophical dispute (Newton versus Descartes) and a still-fragile regime of press control collided in pamphlet form.