Much of the power of Western horror-lore was undoubtedly due to the hidden but often suspected presence of a hideous cult of nocturnal worshipers whose strange customs--descended from pre-Aryan and pre-agricultural times when a squat race of Mongoloids roved over Europe with their flocks and herds--were rooted in the most revolting fertility-rites of immemorial antiquity. This secret religion, stealthily handed down amongst peasants for thousands of years despite the outward reign of the Druidic, Graeco-Roman, and Christian faiths in the regions involved, was marked by wild "Witches' Sabbaths" in lonely woods and atop distant hills on Walpurgis Night and Hallowe'en, the traditional breeding-seasons of the goats and sheep and cattle; and became the source of vast riches of sorcery legend, besides provoking extensive witchcraft prosecutions of which the Salem affair forms the chief American example. Akin to it in essence, and perhaps connected with it in fact, was the frightful secret system of inverted theology or Satan-worship which produced such horrors as the famous "Black Mass"; whilst operating toward the same end we may note the activities of those whose aims were somewhat more scientific or philosophical--the astrologers, cabbalists, and alchemists of the Albertus Magnus or Raymond Lully type, with whom such rude ages invariably abound. The prevalence and depth of the medieval horror-spirit in Europe, intensified by the dark despair which waves of pestilence brought, may be fairly gauged by the grotesque carvings slyly introduced into much of the finest later Gothic ecclesiastical work of the time; the demoniac gargoyles of Notre Dame and Mont St. Michel being among the most famous specimens. And throughout the period, it must be remembered, there existed amongst educated and uneducated alike, a most unquestioning faith in every form of the supernatural; from the gentlest of Christian doctrines to the most monstrous morbidities of witchcraft and black magic. It was from no empty background that the Renaissance magicians and alchemists--Nostradamus, Trithemius, Dr. John Dee, Robert Fludd, and the like--were born.
In this fertile soil were nourished types and characters of somber myth and legend which persist in weird literature to this day, more or less disguised or altered by modern technique. Many of then were taken from the earliest oral sources, and form part of mankind's permanent heritage. The shade which appears and demands the burial of its bones, the demon lover who comes to bear away his still living bride, the death-fiend or psychopomp riding the night-wind, the man-wolf, the sealed chamber, the deathless sorcerer--all those may be found in that curious body of mediaeval lore which the late Mr. Baring-Gould so effectively assembled in book form. Wherever the mystic Northern blood was strongest, the atmosphere of the popular tales became most intense; for in the Latin races there is a touch of basic rationality which denies to even their strangest superstitions many of the overtones of glamour so characteristic of our own forest-born and ice-fostered whisperings.