Désiré-Félicien-François-Joseph Cardinal Mercier (November 21, 1851—January 23, 1926) was a Belgian prelate of the Roman Catholic Church. He served as Archbishop of Mechelen from 1906 until his death, and was elevated to the cardinalate in 1907. Mercier is noted for his staunch resistance to the German occupation of 1914, and is considered to have been the mentor of Leo Cardinal Suenens.
Mercier was the nephew of Reverend Adrien Croquet. In the 1860s Rev. Croquet (renamed Crockett) became a missionary to the Grand Ronde Indian Reservation in Oregon. In the 1870s, a cousin to Mercier, Joseph Mercier, joined his uncle Rev. Croquet in Oregon and married into the Native Tribes. Today, there are several thousand descendants of Joseph as members of the Tribe. Three of Mercier's sisters became nuns, and his brother Léon became a physician.
In 1877 he began teaching philosophy at Mechelen's minor seminary, of which he also became spiritual director. His comprehensive knowledge of St. Thomas Aquinas earned him the newly-erected chair of Thomism at the Louvain in 1882. It was in this post, which he retained until 1905, that he forged a lifelong friendship with Dom Columba Marmion, an Irish Thomist. Raised to the rank of Monsignor on May 6, 1887, Mercier founded the Higher Institute of Philosophy at Louvain's Catholic university in 1899, which was to be a beacon of Neo-Thomist philosophy. He founded in 1894 and edited until 1906 the Revue Néoscholastique, and wrote in a scholastic manner on metaphysics, philosophy, and psychology, several of his works being translated into English, German, Italian, Polish, and Spanish. His most important book was Les origines de la psychologie contemporaine (1897).
His reputation within his field obtaining the recognition of Pope Pius X, Mercier was appointed Archbishop of Mechelen and thus Primate of Belgium on February 7, 1906. He received his episcopal consecration on the following March 25 from Archbishop Antonio Vico, and took as his episcopal motto: Apostolus Jesu Christi. Mercier was created Cardinal Priest of S. Pietro in Vincoli by Pope St. Pius X in the consistory of April 15, 1907.
In 1914 the German army attempted a surprise invasion of France by invading neutral Belgium. Mercier had to leave his see on August 20 of that same year to attend the funeral of the late Pius X, and participate in the following conclave. His first port of call upon his return to Belgium was Havre to meet wounded Belgian, French and British troops. When he returned to his archdiocese, the Mechelen Cathedral was partially destroyed.
In the German Imperial atrocities that ensued, thirteen of the priests in Mercier's diocese were killed, not to mention many civilians, by Christmas 1914, when Mercier's pastoral, Patriotism and Endurance, was distributed to be read aloud in all Belgian churches in January 1915. The pastoral letter had to be distributed by hand as the Germans had cut off the postal service. His passionate, unflinching words were taken to heart by the suffering Belgians.
He embodied Belgian resistance to the occupying power. He sometimes became a focus of Allied Propaganda during the War. He was kept under house arrest by the Germans, and many priests who had read the letter aloud in public were arrested as well. Pope Benedict XV sent his portrait and a letter of whole-hearted support to Mercier in 1916, and a one point told him "You saved the Church!"
From 1921 to 1926 he held regular conversations with Anglican theologians, notably Edward, Lord Irwin (later Lord Halifax), foreshadowing the Church's future dialogue with the Anglicans. Anglicanism, Mercier believed, must be "united, not absorbed. Also worthy of note, is Mercier's role in recognizing the mathematical talent of a young Belgian seminarian, Georges Lemaître, and urging Lemaitre to study Einstein's theories of relativity. Lemaître became an early expert in general relativity as it applied to cosmological questions, and he went on to propose an expanding model of the universe, based on both Einstein's and de Sitter's models. His Primeval Atom hypothesis was developed by Gamow, Alpher and Herman into the better known Big Bang theory of the origin of the universe.
Mercier is also known for opposing the use of Dutch (language spoken by the Flemish majority) in Belgium. This was sparked by a conversation with a Flemish priest, whom he told the following: "Moi je suis d'une race destinée à dominer et vous d'une race destinée a servir" (English: "I belong to a race destined to dominate and you belong to a race destined to serve"). For this he is often called a Vlamingenhater (someone who hates Flanders and its inhabitants).
Following World War I, Mercier undertook an excursion to raise funds to rebuild and stock a new library of the University of Luvain. The original library had been burned by the Germans in the war. In his travels to raise funds, Mercier visited New York for his first and only time.
Mercier suffered from persistent dyspepsia, and in early January 1926 he underwent surgery for a lesion of the stomach. During surgery, the anaesthetized Cardinal even held a conversation with his surgeon.
In his final days, Mercier was visited by the likes of King Albert and Queen Elizabeth, Lord Halifax, and family members. He entered a deep coma around 2:00 p.m. on January 23, and died an hour later, at age 74. The Cardinal was buried at St. Rumbolds Cathedral.
The Cardinal harbored great devotion to the Sacred Heart.