KLEUTGEN, JOSEPH. - Jesuit theologian and philosopher, b. 9 Apr. 1811 at Dortmund (Westphalia), d. 13 Jan. 1883 at S. Antonio di Caldaro (Upper Adige). After teaching ethics and rhetoric for three years, in 1843 he was called to Rome to the General Curia of the Order, of which he was also secretary for three years. When the Vatican Council was suspended, in which he had collaborated as a private theologian of the bishop of Paderborn, taking part in the definitive drafting of the constitution *De fide catholica*, he retired to the Tyrol. He was recalled thence in 1878 by Leo XIII, who entrusted him with the prefecture of studies and the chair of dogmatics at the Gregorian University; it seems that the first draft of the encyclical *Aeterni Patris* is to be attributed to him. But shortly afterwards an apoplectic attack forced him to return to the Tyrol. He nevertheless continued to work on a great theological work, conceived in 8 volumes, of which only the first appeared: *Institutiones theologicae: De ipso Deo* (Regensburg 1881).
Kleutgen, by reason of the works he wrote and the influence he exerted, holds an eminent place among the scholastics of the 19th century and may be considered the most effective restorer of scholastic philosophy in Germany. Kantian speculation had indeed produced among Catholic theologians a disorientation and an undervaluation of the scholastic tradition. Kleutgen sought to demonstrate to Hermes, Günther and Hirscher that all the errors of their new theology condemned by Rome derived precisely from their rejection of traditional philosophical-theological principles. To this end he wrote his two fundamental works: *Die Theologie der Vorzeit vertheidigt* (3 vols., Münster 1853-60; 2nd ed., 5 vols., ibid. 1867-74) and *Die Philosophie der Vorzeit vertheidigt* (2 vols., ibid. 1860-63; 2nd ed. Innsbruck 1878), together with three supplementary pamphlets: *Die Verurteilung des Ontologismus* (Münster 1867); *Vom Intellectus agens u. d. angeborenen Ideen* (ibid. 1875); *Zur Lehre vom Glauben* (ibid. 1875). These works are distinguished by acute arguments, wide erudition, moderation, precision and clarity. Although described as “defences,” the philosophy presented (with a fundamentally Thomistic orientation but with contributions from other scholastics, particularly Suarezian) was even more “exposition” (a point highlighted in the title of the Italian version, edited by Card. Reisch and Fr. Curci: 5 vols., Rome-Turin 1866-68). A particular merit of Kleutgen was his thorough presentation of the problem of knowledge and his discussion of the judgments on the relationship between science and faith.
Other works by Kleutgen include biographical writings, letters from Rome, sermons etc., collected in *Kleinewe Werke* (5 vols., Münster 1869-74; Regensburg 1880-85); in vol. III the dissertation *Über die alte und neue Schule* (1st ed. 1846; Latin trans., 1889), in defence of the old school; and the *Ars dicendi...* (1st ed., Rome 1874; 21st ed. Turin 1928), considered a classic.