Theologian; b. Marche, Belgium, July 30, 1890; d. Lenz, France, May 23, 1940. He entered the Society of Jesus in 1907. During his theological studies (1914–18) he began the long work that, with many other absorbing activities, was to occupy him until his premature death 23 years later: a synthesis of the doctrine of the mystical body of christ as the center of all the great Christian dogmas. As philosophy professor at Namur from 1920 to 1935, he assumed various intellectual and religious tasks at the college, at the diocesan seminary, and in the city itself. Among his philosophical works, L'Obligation morale: Principe de liberté (Louvain 1927) stands out. Mersch's religious influence was profound because of his human warmth and his ability to inspire others with his own ideals.
Before trying to construct the dogmatic synthesis of the doctrine of the Mystical Body, Mersch realized that a preliminary work based on scripture and patristic tradition was necessary. Lengthy research occupied all of his free time from 1920 to 1929, and he published in 1933 the two-volume Le Corps mystique du Christ: Études de théologie historique (Louvain). The book was an immediate success, not only among Catholics, but also in Protestant theological circles. This success necessitated a second (1936) and a third (1951) edition, and in 1938 the English translation, The Whole Christ, was published (Milwaukee).
Mersch then returned to his initial plan, the theological synthesis of the doctrine of the Mystical Body. After his death three successive drafts were identified. While contributing many articles on this subject to various magazines (e.g., 24 articles in Nouvelle Revue Théologique from 1926 to 1940), he almost completed the third draft of his synthesis at Louvain (1935–40). He drew up a moral and ascetic synthesis parallel to the dogmatic synthesis: Morale et corps mystique appeared in 1937 [4th edition in 1951; English translation: Morality and the Mystical Body (New York 1939)].
In the beginning of May 1940, Mersch was forced by the events of war to leave Louvain for exile, having been given the task of looking out for the safety of several older fathers. He took with him the manuscript of the third draft of his dogmatic synthesis. His life ended in a series of acts of self-sacrifice. On May 23, 1940, in the presbytery of the French town of Lenz, in spite of the frequent bombardments, he offered to take relief to several wounded persons. In this act of charity he met death, a death probably preceded by a great sacrifice for him: uncertainty for two days about the fate of his manuscript, in which he had concentrated so much hope. His body was first buried in the cemetery of Lenz; after the war it was brought back to Namur.
The manuscript of the completed part of the third draft of his dogmatic synthesis was recovered. With the help of the two former drafts left by the author at Louvain and at Brussels, the work was reconstructed enough to remain the faithful expression of his whole thought. In July 1944, it appeared in two volumes under the title Théologie du corps mystique (Brussels) and is now in its 4th edition [English translation: The Theology of the Mystical Body (St. Louis 1951)].
Bibliography: j. levie, "Le Père Émile Mersch," in e. mersch, Théologie du corps mystique, 2 v. (Brussels 1944) 1:vii–xxxiii, with bibliography of Mersch's works. g. dejaifve, "'La Théologie du corps mystique' du P. Ém. Mersch," Nouvelle revue théologique 67 (1945) 1016–24.