(Michel de Bay) (1513-1589) Theologian, author of a system known as Baianism, born Melin, Belgium; died Louvain. Ordained in 1541, he taught philosophy at Louvain, where he became president of the College Adrien and professor of Scripture. His system, which ignored the supernatural, was a mixture of Pelagianism and Calvinism. About 1559 propositions from his lectures were condemned by the Sorbonne, and later by Pope Pius V. Baius finally submitted to Gregory XIII, 1579, but his teachings had prepared the way for Jansenism.