Charles Loyson (shärl lwäzôN´), 1827–1912, French preacher, called Père Hyacinthe. He was successively a Sulpician, a Dominican, and a Carmelite. In 1869, when he was perhaps the best-known preacher in France, he opposed the calling of the Vatican Council. He opposed enunciation of the doctrine of the infallibility of the pope, and in 1871 he left the Church. In 1878 he founded a Gallican church at Paris; this joined later (1893) with the Jansenists of Utrecht.