The term Modern Satanism is not intended to signify the development of some new aspect of old doctrine concerning demonology, or some new argument for the personification of the evil principle in universal nature. It is intended to signify the alleged revival, or, at least, the reappearance to some extent in public, of a cultus diabolicus, or formal religion of the devil, the existence of which, in the middle ages, is registered by the known facts of the Black Sabbath, a department, however, of historical research, to which full justice yet remains to be done. By the hypothesis, such a religion may assume one of two forms; it may be a worship of the evil principle as such, namely, a conscious attempt on the part of human minds to identify themselves with that principle, or it may be the worship of a power which is regarded as evil by other religions, from which view the worshippers in question dissent. The necessity for this distinction I shall make apparent in the first chapter of this book. A religion of the darkness, subsisting under each of these distinctive forms, is said to be in practice at the present moment, and to be characterised, as it was in the past, by the strong evidence of miracles,—in other words, by transcendental phenomena of a very extraordinary kind, connecting in a direct manner with what is generically termed Black Magic. Now, Black Magic in the past may have been imposture reinforced by delusion, and to state that it is recurring at the present day does not commit anyone to an opinion upon its veridical origin. To say, also, that the existence of modern diabolism has passed from the region of rumour into that of exhaustive and detailed statement, is to record a matter of fact, and I must add that the evidence in hand, whatever its ultimate value, can be regarded lightly by those only who are unacquainted with its extent and character. This evidence is, broadly, of three kinds:—(a) The testimony of independent men of letters, who would seem to have come in contact therewith; (b) the testimony volunteered by former initiates of such secret associations as are dedicated to a cultus diabolicus; (c) the testimony of certain writers, claiming special sources of information, and defending some affected interests of the Roman Catholic Church.

My purpose in this book is to distinguish, so far as may be possible, what is true from what is false in the evidence, and I have undertaken the task, firstly, because modern mystics are accused, en masse, of being concerned in this cultus; secondly, because the existence of modern Satanism has given opportunity to a conspiracy of falsehood which is wide in its ramifications, and serious on account of its source; thirdly, because the question itself has awakened considerable interest both within and without transcendental circles, and it is desirable to replace hazy and exaggerated notions by a clear and formal statement.

I have connected the new diabolism with France in my title, because the evidence in each of its kinds has been filed by French writers, and we have no other source of information. So far as that evidence is sound, we have to thank France for producing it; but, on the other hand, should it prove that a whole city of invention has been constructed, “with all its spires and gateways,” upon a meagre basis of fact, it is just that French imagination should have full credit for the decorative art which has adorned this Question of Lucifer.

The plan of my work had been sketched, and a number of chapters written, when I found myself to some extent preceded by a writer well known to occultists under the pseudonym of Papus, who has quite recently published a small brochure, entitled Le Diable et L’Occultisme, which is a brief defence of transcendentalists against the accusations in connection with Satanism. I gladly yield to M. Papus the priority in time, which was possible to a well-informed gentleman, at the centre of the conspiracy. His little work, however, does not claim to be either a review or a criticism, and does not therefore, in any sense, cover the ground which I have travelled. It is an exposition and exoneration of his own school of mystic thought, which is that of the Martinists, and I have mentioned it in this connection in its proper place.