Haffner, Paul Leopold. – Bishop of Mainz, b. at Horb in Württemberg on 21 Jan. 1829, d. at Mainz on 2 Nov. 1899. Professor at the Mainz Seminary during the *Kulturkampf*, he became, alongside his bishop Ketteler, the soul of the Catholic movement, employing his rich gifts as an orator, journalist, and writer.
He became renowned for his speeches at Catholic congresses (*Katholikentage*), especially that of 1877; he was one of the founders of the Görres-Gesellschaft, directing its philosophical section; from 1864 he was a member of the directing committee for the publication of the *Frankfurter Zeitgemäßen Broschüren*. In his writings on Christian social order, he followed in the footsteps of Bishop Ketteler, whose successor he also became in the episcopal see of Mainz in 1886, after a nine-year vacancy.
Principal works: *Die deutsche Aufklärung* (Mainz 1864); *Der Materialismus in der Kulturgeschichte* (ibid. 1865); *Grundlinien der Philosophie* (2 vols., ibid. 1881–1883); *Der Versuch eines Dilettanten* (under the pseudonym Minranov, ibid. 1879); *Wie machen wir's, dass wir kommen in Abrahams Schoss* (under the same pseudonym, ibid. 1879); *Sozialer Katechismus* (under the pseudonym Artur V. Hohenberg [ibid. 1879, new ed. by F. Kirchschmidt 1925]).