JOHN OF WESALIA (Johann von Wesel). - Theologian, whose real name was Johann Rucherath or Richerath, b. at Oberwesel in the early 15th century, d. at Mainz in 1481. Nothing is known of his early youth, since certain information about him begins only from 1440, the year in which he entered the University of Erfurt, where in 1445 he obtained the degree of magister artium, subsequently taking his doctorate in theology on 15 November 1456; he also taught there for some years, until he went to Worms in 1460 as a canon. He was also a professor of theology at Basel, but soon returned to Worms (1463) as preacher of the Cathedral, an office he held until 1477, when he was deposed by Bishop Reinhard von Sickingen because of the scandal aroused by his sermons, directed above all against the Church of Rome.
Shortly afterward, however, he obtained a similar post in the cathedral of Mainz, where he had been summoned by Archbishop Diether von Isemburg. Here he formed relations with a Bohemian Hussite, a certain Nicholas, for whom he wrote the treatise Super modo obligationis legum humanarum ad quendam Nicolaum de Bohemia, intended for the Hussites. Summoned for this reason before a tribunal of theologians of the Universities of Cologne and Heidelberg, he recanted his errors (21 February 1479), but was nevertheless confined for life in the Augustinian convent in Mainz. The errors of J. of W. concerning the Church, which he regarded as an invisible society (quam nemo sciat nisi Deus), concerning indulgences, predestination, the cult of the saints, and transubstantiation correspond roughly to those upheld by John Hus (v.).
The writings of J. of W., partly still unpublished, are: Adversus indulgentias disputatio (ed. Ch. W. F. Walch, in Monumenta medii aevi, II, 1, Göttingen 1757, pp. 111-156), directed against the papal indulgence for the jubilee year 1450; Opusculum de auctoritate, officio et potestate postorum ecclesiasticorum (ed. Walch, op. cit., II, II, p. 142 ff.), in which he denounced the defects of both the higher and the lower clergy; De potestate ecclesiastica; De indulgentiis and De ieiunio, now lost. Of doubtful attribution, finally, are the two treatises De processione Spiritus Sancti and De peccato mortali.