Walter of Mortagne

Walter of Mortagne (c. 1100–1174) was a Flemish Scholastic philosopher and Catholic theologian. He was educated in the schools of Tournai and studied under William of Champeaux. In 1120, he began teaching in Laon, where he clashed with Alberich of Reims. Between 1136 and 1144, he taught at the School of St. Genevieve in Paris. Afterward, he returned to Laon and was appointed bishop. Walter's major works include a treatise on the Trinity and six 'Opuscula.' He also authored a logical commentary and a letter to Abelard discussing the Platonic view of the body hindering the soul's aspirations. In his work 'De sacramento conjugii,' he addressed the sacrament of marriage, stating consent is key, but a woman's silence implies consent. Philosophically, Walter is known for his views on universals, leading the Indifferentists. This school of thought posited that universals are indifferent in themselves, only becoming predicates of individual subjects through various determinations or viewpoints. This theory emphasized individual existence and suggested unity in universals arises from thought, challenging exaggerated realism and paving the way for moderate realism in the 13th century.