"Horror in literature attains a new malignity in the work of Matthew Gregory Lewis (1773-1818), whose novel The Monk (1796) achieved marvelous popularity and earned him the nickname 'Monk' Lewis. This young author, educated in Germany and saturated with a body of wild Teuton lore unknown to Mrs. Radcliffe, turned to terror in forms more violent than his gentle predecessor had ever dared to think of; and produced as a result a masterpiece of active nightmare whose general Gothic cast is spiced with added stores of ghoulishness. The story is one of a Spanish monk, Ambrosio, who from a state of over-proud virtue is tempted to the very nadir of evil by a fiend in the guise of the maiden Matilda. . . . The novel contains some appalling descriptions such as the incantation in the vaults beneath the convent cemetery, the burning of the convent, and the final end of the wretched abbot. In the sub-plot where the Marquis de las Cisternas meets the specter of his erring ancestress, The Bleeding Nun, there are many enormously potent strokes; notably the visit of the animated corpse to the Marquis's bedside, and the cabalistic ritual whereby the Wandering Jew helps him to fathom and banish his dead tormentor. . . ." -- H. P. Lovecraft, "Supernatural Horror In Literature"
