“Though an ardent, uncompromising enthusiast, des Mousseaux unwittingly transforms himself into the tempting demon, or – as he is fond of calling the Devil – the “serpent of Genesis”. In his desire to demonstrate in every manifestation the presence of the Evil One, he only succeeds in demonstrating that Spiritualism and magic are no new things in the world, but very ancient twin brothers, whose origin must be sought for in the earliest infancy of ancient India, Chaldea, Babylonia, Egypt, Persia, and Greece.
He proves the existence of “spirits”, whether these be angels or devils, with such a clearness of argument and logic, and such an amount of evidence, historical, irrefutable, and strictly authenticated, that little is left for spiritualist authors who may come after him. How unfortunate that the scientists, who believe neither in devil nor spirit, are more than likely to ridicule M. des Mousseaux’s books without reading them, for they really contain so many facts of profound scientific interest!
But what can we expect in our own age of unbelief, when we find Plato, over twenty-two centuries ago, complaining of the same? Me too”, says he, in his Euthyphron, “when I say anything in public assembly concerning divine things, and predict to them what is going to happen, they ridicule as mad; and although nothing that I have predicted has proved untrue, yet they envy all such men as we are. However, we ought not to heed, but pursue our own way.”
The literary resources of the Vatican and other Catholic repositories of learning must have been freely placed at the disposal of these modern authors. When one has such treasures at hand – original manuscripts, papyri, and books pillaged from the richest heathen libraries; old treatises on magic and alchemy; and records of all the trials for witchcraft, and sentences for the same to rack, stake, and torture, it is mighty easy to write volumes of accusations against the Devil.
We affirm on good grounds that there are hundreds of the most valuable works on the occult sciences, which are sentenced to eternal concealment from the public, but are attentively read and studied by the privileged who have access to the Vatican Library. The laws of nature are the same for heathen sorcerer as for Catholic saint, and a “miracle” may be produced as well by one as by the other, without the slightest intervention of God or devil.”
H. P. Blavatsky
The Mark Of God: Understanding Your "I AM Presence" 