DU PLESSIS MORNAY, PHILIPPE. - Calvinist writer, b. at Buly in the Vexin on 5 Nov. 1549, d. at La Forêt-sur-Sèvre on 11 Nov. 1623. From childhood drawn to Calvinism, he placed the resources of a brilliant intellect and above all an intense activity at the service of heresy, which earned him the title of "Pope of the Huguenots." The painful episode of the St. Bartholomew’s Night drove him to publish under the pseudonym of Brutus Stephanus Iunius the important work: Vindiciae contra tyrannos, Edinburgh 1579 (though this authorship is still not definitively settled by critics), from which the Huguenots drew polemical weapons to defend the right of rebellion. With his skill he succeeded in gaining the confidence of Henry IV, King of Navarre, who appointed him his counsellor. He exploited this position to the advantage of his coreligionists, urging the king to promulgate the Edict of Nantes (1598).
The publication of his work on the Eucharist, De l’institution, usage et doctrine de l’Eucharistie en l’Église ancienne, comment, quand et par quels degrez la Messe s’est introduite à sa place (La Rochelle 1598), rekindled a most bitter controversy with Catholics, who found their defender in Jacques Davy Du Perron, Bishop of Evreux. Du Plessis Mornay had adduced in support of his thesis an abundant body of material, nearly 5,000 quotations, drawn from the Fathers and ecclesiastical writers with little or no critical judgment. Du Perron easily accused him before public opinion of ignorance and bad faith, and Du Plessis Mornay, stung to the quick, demanded a public disputation. The affair transcended the limits of a mere polemic; the fame of the two men aroused singular expectations in the public. Henry IV, who had meanwhile become a Catholic, manifestly favouring his terror of the Calvinists towards the Church, readily consented to the disputation taking place at Fontainebleau, entrusting the presidency to Bellèvre and appointing as arbiters two Catholics and two Calvinists. Du Plessis Mornay at first sought to postpone the encounter; then, constrained by circumstances to sustain the debate, he defended himself so poorly that Du Perron easily triumphed. Du Plessis Mornay, however, wished to make a personal defence and presented the Fontainebleau conference in a very different light in his Discours véritable de la conférence tenue à Fontainebleau (Paris, Sedan, La Rochelle, Montauban 1600), which not only failed to regain him favour but harmed him further, since his opponent was compelled to make the acts of the conference public: Actes de la conférence tenue à Fontainebleau (Evreux 1601). Irritated, Du Plessis Mornay attempted to reopen the debate by publishing a Réponse au livre publié par le sieur Evreux d'Evreux (Saumur 1602), but by then his prestige was compromised. Nor did he benefit from another work published about ten years later: Le mystère d'iniquité (ibid. 1611), full of venomous attacks against the Pope, whom he portrayed as an usurper of authority. He also wrote four volumes of Mémoires, published posthumously, the first two at La Forêt in 1624-25 and the other two at Amsterdam in 1652-53. All his works are on the Index (decrees 31 May 1629; 11 Sept. 1629).