Coster, Francois a Belgian theologian, was born at Mechlin in 1531. In 1551 he was received into the Jesuit ranks by Ignatius Loyola himself. In 1555 he received the degree of doctor of theology at Cologne, and there taught belles-lettres, philosophy, and theology. He was afterwards charged with the mission of propagating Jesuitism in the Low Countries and the Rhenish provinces. He zealously combated the Protestants, and thus Obtained the name of .Malleus Hcereticorum. He died at Brussels, December 6, 1619, leaving Responsio ad Andreaqal Calliam Calvinistam (Cologne, 1586): — Enchiridion Controversiarum (in Latin and Flemish, ibid. 1600): — Epistola ad Franciscum Gomarum, contra Anti-Costerum (ibid.): — Epistola ad Gasp. Grevinchovium (ibid.): — Institutionum Christianarum libri 4 (Antwerp and Cologne, 1604): — Demonstratio Veteris Orthodoxce Fidei, etc. (Cologne, 1607): — Responsio ad Luccam Osiandrum, etc. (ibid. 1608), and several other works of controversy or religion, in both Latin and Flemish. See Hoefer, Nouv. Biog. Generale, s.v.; Wetzer u. Welte, Kirchen-Lexikon, s.v.