INSTITORIS, HEINRICH (Henricus de Slectat). — Dominican theologian, born in Schlettstadt around 1430, died in Moravia in 1505. He was teaching theology when Bishop Rudolf of Lavant commissioned him to preach the crusade against King George Poděbrady of Bohemia. On 13 March 1479, he was appointed by Sixtus IV inquisitor throughout Upper Germany, where he began the struggle against heretics and particularly against witches, especially in Constance, Bressanone, and Innsbruck. Alexander VI (31 January 1500) appointed him nuncio and inquisitor in Bohemia and Moravia against the “Moravian Brethren.”
He left many writings against heresy and in defense of the papacy; the following may be noted: Malden maleficarum (Lyons 1484), written in collaboration with Giacomo Sprenger; Tractatus varii contra 4 errores novissime exortos adversus Eucharistiae sacramentum (Nuremberg 1496); Tractatus adv. errores A. Roselli de plenaria potestate pontificis ac monarchiae (Venice 1499); Opus perutile sermonum in defensionem S. Rom. Ecclesiae adversus Waldenses (Olmütz 1501); S. Romanae Ecclesiae fidei defensionis Clypeus adversus Waldensium seu Pichardorum haeresium (there 1502).