Side by side with the scholastic literature of Rabbinism flourished popular ethical literature (_musar_[181]). Its originators were the preachers (_darshanim_), some of whom occupied permanent posts attached to synagogues, while others wandered about from town to town. The synagogue sermons of that period, which have come down to us in various collections,[182] consist of a long string of Haggadic and Cabalistic quotations, by means of which the Biblical texts are given an entirely perverted meaning. The preachers were evidently less anxious to instruct their audience than to exhibit their enormous erudition in theological literature. Some of these preachers endeavored in particular to foist upon the people the notions of the "Practical Cabala."[183] The "secret" writings of Ari[184] and his school were circulated in Poland in manuscript copies, which went from hand to hand. The ideas embodied in the Cabalistic doctrine of Ari were popularized in the shape of "gruesome stories" concerning life after death, the tortures of the sinners in hell, the transmigration of souls, and the exploits of demons. The books which endeavored to inculcate piety among the masses by means of these stories became rapidly popular. Towards the end of the seventeenth century, the Cabalist Joseph Dubno wrote a work in this spirit under the title _Yesod Yoseph_, "Foundation of Joseph." Prior to its publication, Dubno's work was utilized by Hirsch Kaidanover, a son of the above-mentioned rabbi of Cracow, Aaron Samuel Kaidanover,[185] and issued by him in an improved and amplified version in Frankfort-on-the-Main, in 1705, under the name _Kab ha-Yashar_, "The Just Measure." A few years later the book was published also in the Yiddish vernacular, and became a great favorite among the lower classes as well as among women. The _Kab ha-Yashar_ breathes a spirit of gloomy asceticism, and is expressive of a funereal frame of mind. "O man,"--the author exclaims--"wert thou to know how many demons thirst for thy blood, thou wouldst abandon thyself entirely, with heart and soul, to Almighty God!" The air, according to the doctrine preached in this book, is filled with the invisible spirits of the dead who can find no rest in the other world, and teems with the wandering shadows of sinners and demons, who frequently slip into living beings and force them to rage like madmen. Scores of "reliable" stories are quoted, telling of the conflicts between men and demons and of the exploits of miracle-workers who have exorcised the evil spirits by means of incantations.