advance the knowledge of this force of nature. Those obscure or superficially verbose works which pretend to offer solutions for the serious questions of our times, or, at least, to prepare the way thereto, are even impediments and causes of delay, because they bewilder weak or unschooled brains, suggest to them erroneous views, and make them either more inaccessible to rational information or altogether closed to it. The reader is now placed at those points of view whence he can see the new æsthetic tendencies in their true light and their real shape. It will be the task of the following books to demonstrate the pathological character of each one of these tendencies, and to inquire what particular species of degenerate delirium or hysterical psychological process they are related to or identical with. BOOK II. _MYSTICISM._ CHAPTER I. THE PSYCHOLOGY OF MYSTICISM. WE have already learnt to see in mysticism a principal characteristic of degeneration. It follows so generally in the train of the latter, that there is scarcely a case of degeneration in which it does not appear. To cite authorities for this is about as unnecessary as to adduce proof for the fact that in typhus a rise in the temperature of the body is invariably observed. I will therefore only repeat one remark of Legrain’s:[64] ‘Mystical thoughts are to be laid to the account of the insanity of the degenerate. There are two states in which they are observed--in epilepsy and in hysterical delirium.’ When Federoff,[65] who makes mention of religious delirium and ecstasy as among the accompanying features of an attack of hysteria, puts them down as a peculiarity of women, he commits an error, since they are at least as common in male hysterical and degenerate subjects as in female. What is really to be understood by this somewhat vague term ‘mysticism’? The word describes a state of mind in which the subject imagines that he perceives or divines unknown and inexplicable relations amongst phenomena, discerns in things hints at mysteries, and regards them as symbols, by which a dark power seeks to unveil or, at least, to indicate all sorts of marvels which he endeavours to guess, though generally in vain. This condition of mind is always connected with strong emotional excitement, which consciousness conceives to be the result of its presentiments, although it is this excitement, on the contrary, which is pre-existent, while the presentiments are caused by it and receive from it their peculiar direction and colour.