FROM the end of the thirteenth to the beginning of the fifteenth century may be called the golden age of mystical literature in the vernacular. In Germany, we find Mechthild of Magdeburg (d. 1277), Meister Eckhart (d. 1327), Johannes Tauler (d. 1361), and Heinrich Suso (d. 1365); in Flanders, Jan Ruysbroek (d. 1381); in Italy, Dante Alighieri himself (d. 1321), Jacopone da Todi (d. 1306), St. Catherine of Siena (d. 1380), and many lesser writers who strove, in prose or in poetry, to express the hidden things of the spirit, the secret intercourse of the human soul with the Divine, no longer in the official Latin of the Church, but in the language of their own people, “a man’s own vernacular,” which “is nearest to him, inasmuch as it is most closely united to him.”