Be that as it may, his book has seemed to me most interesting in divers respects, and I confidently submit it to that select public for whom the invisible world is not a chimera. I should be much surprised if, after opening it at random, the reader was not tempted to retrace his steps and go on to the end. The philosopher, the confessor, the medical man will find therein, in conjunction with the robust faith of the middle ages, novel and ingenious views; the literary man, the curioso, will appreciate the solidity of reasoning, the clearness of style, the liveliness of recitals (for there are stories, and delicately told). All theologians have devoted more or less pages to the question of material intercourse between man and the demon; thick volumes have been written about witchcraft, and the merits of this work were but slender if it merely developed the ordinary thesis; but such is not its characteristic. The ground-matter, from which it derives a truly original and philosophical stamp, is an entirely novel demonstration of the existence of Incubi and Succubi, as rational animals, both corporeal and spiritual like ourselves, living in our midst, being born and dying like us, and lastly redeemed, as we are, through the merits of Jesus-Christ, and capable of receiving salvation or damnation. In the Father of Ameno’s opinion, those beings endowed with senses and reason, thoroughly distinct from Angels and Demons, pure spirits, are none other but the Fauns, Sylvans and Satyrs of paganism, continued by our Sylphs, Elfs and Goblins; and thus is connected anew the link of belief. On this score alone, not to mention the interest of details, this book has a claim to the attention of earnest readers: I feel convinced that attention will not be found wanting. I. L. _May 1875._ * * * * * The foregoing advertisement was _composed_ at the printer’s, and ready for the press, when, strolling on the quays[2], I met by chance with a copy of the _Index librorum prohibitorum_. I mechanically opened it, and the first thing that struck my eyes was the following article: De Ameno Ludovicus Maria. _Vide_ Sinistrari. [2] Paris Embankment. My heart throbbed fast, I must confess. Was I at last on the trace of my author? Was it _Demoniality_ that I was about to see nailed to the pillory of the _Index_? I flew to the last pages of the formidable volume, and read: SINISTRARI (Ludovicus Maria) de Ameno, De Delictis et Pœnis Tractatus absolutissimus. _Donec corrigatur. Decret. 4 Martii 1709._ _Correctus autem juxta editionem Romanam anni 1753 permittitur._