In his definition of mysticism Nordau says that “the word describes a state of mind in which the subject imagines that he sees or divines unknown and inexplicable relations amongst phenomena, discerns in things hints at mysteries, and regards them as symbols.” But he adds, “by which dark powers seek to unveil, or, at least, to indicate all sorts of marvels which he endeavours to guess, though generally in vain.” We have divided his definition into two parts, because placed in one sentence it seems an incorrect and unfair definition, the former part of which might be used as a proof of degeneration in a perfectly sound mind, while the latter part is the essential of the whole definition. As we have already pointed out, science and all researches have utterly failed to furnish replies to all questions regarding the origin, aim, plan, and final destiny of the universe and of humanity. Under such circumstances, the world around us, that which has preceded it, that which will follow it, as well as ourselves, necessarily remain mysteries. Can then any one who perceives or divines unknown, and to us now inexplicable, relations between phenomena and who discerns mysteries be regarded as a degenerate? All the scientific facts of which we are now in possession were mysteries before they were discovered, and the scientists who, guided by slight hints and sometimes by guesses, have unravelled the marvels of nature, could not surely be put down as lunatics. It is therefore evident that the phrase “dark power” is a most essential part in Nordau’s definition, and that a man can behold mysteries, dwell on them, study them, sometimes unravel them, and remain a perfectly sane man, and that he only who is mystical and deals with mysteries in an irrational way is a degenerate. Nordau says as much in his illustration of the peasant who is a mystic in his religion and in his belief in the weather-witch, but a matter-of-fact man in his farming and in his business. But he is not so lenient to the exponents of the mystic school in art and literature. With regard to these, he is rather prone to determine the state of their mind according to that part of a quotation from Morel which he has italicised in his book, “_a morbid deviation from an original type_.” The word morbid alone would have sufficed, but he seems to attach more importance to the other part of the sentence and to regard all who deviate from an original type as degenerate. He does not allow for extenuating circumstances in the authors and artists as he does in the case of the peasant. If he did, he could not class any of these, or their admirers, among the degenerates, unless he could also prove that they were irrational in their daily life and their business relations.