BERTHIER, Guillaume-Joseph. - Jesuit of French origin, historian, publicist, and ascetical writer, born at Issoudun on 7 April 1704, entered the Society in 1722, died at Bourges on 15 December 1784. He first taught half of philosophy, then theology. Charged with continuing the *Histoire de l'Église gallicane* of Fathers Longueval and Brunoy, he published volumes XI-XII left by them, then volumes XIII-XVIII of his own composition (Paris, 1744-49). He interrupted this work to take over the direction of the periodical *Mémoires de Trévoux* (1745-62), in which he waged a campaign against Voltaire and the Encyclopedists. When the Society was suppressed in France, he became tutor to the sons of the Dauphin, the future Louis XVI and Louis XVIII; having left the kingdom with several of his confreres in 1764, he returned in 1774.
He devoted his last years to the composition of spiritual works, published after his death: *Le Pautier traduit... avec des notes et des réflexions*, 8 vols., Paris 1785, reprinted in Migne’s *Cursus Scripturae Sacrae*, XIV-XVI; *Réflexions spirituelles*, ibid. 1790, reprinted in 1811 and later under the title *Œuvres spirituelles*. In these last works, of elevated and uncommon tone, one may note the discreet but firm apology for mystical authors (*Lettre sur les œuvres de s. Jean de la Croix*, *Considérations sur la mort mystique*, etc.). The Sulpician Lasausse extracted from them a *Doctrine spirituelle du P. B.*, Paris 1797.