He has made it a matter of conscience, when writing or speaking on occult science, to deal only with matters on which he could also report, in what seemed an adequate manner, the views held by modern science. With this, however, he does not wish in the least to give the impression that this is always a necessary prerequisite. Any one may feel a call to communicate or to publish whatever his judgment, his sense of truth, and his feelings may prompt him to, even if he is ignorant of the attitude taken by contemporary science in the matter. The writer wishes to indicate merely that he holds to the pronouncements he has made. For instance, he would never have written those few sentences on the human glandular system, nor those regarding man's nervous system, contained in this volume, were he not in a position to discuss both subjects in the terms used by the modern scientist, when speaking of the glandular and nervous systems from the standpoint of science.

In spite of the fact that it may be said that he who speaks concerning “heat,” as is done here, knows nothing of the elements of modern physics, yet the author feels himself quite justified, because he believes that he knows present day research along those lines, and because if it were unknown to him, he would have left the subject alone. He knows that such utterances may be ascribed to lack of modesty, but it is necessary to declare his true motives, lest they should be confounded with others of a very different nature, a result infinitely worse than a verdict of mere vanity.

He who reads this book as a philosopher, may well ask himself, “Has this author been asleep to present day research in the field of the theory of cognition? Had he never heard of the existence of a man called Kant?” this philosopher might ask, “and did he not know that according to this man it was simply inadmissible, from a philosophic point of view, to put forward such statements?” and so on, while in conclusion he might remark that stuff of so uncritical, childish, and unprofessional a nature should not be tolerated among philosophers, and that any further investigation would be waste of time. However, here again, for reasons already advanced and at the risk of being again misinterpreted, the writer would fain introduce certain personal experiences.

His studies of Kant date from his sixteenth year, and he really believes he is now capable of criticizing quite objectively, from the Kantian point of view, everything that has been put forward in this [pg xxv] book. On this account, too, he might have left this book unwritten were he not fully aware of what moves a philosopher to pass the verdict of “childishness” whenever the critical standard of the day is applied. Yet one may actually know that in the Kantian sense the limits of possible knowledge are here exceeded: one may know in what way Herbart (who never arrived at an “arrangement of ideas”) would discover his “naive realism.” One may even know the degree to which the modern pragmatism of James and Schiller and others would find the bounds of “true presentments” transgressed—those presentments which we are able to make our own, to vindicate, enforce, and to verify.

We may know all these things and yet, for this very reason, feel justified in holding the views here presented. The writer has dealt with the tendencies of philosophic thought in his works: “The Theory of Cognition of Goethe's World-Concept”; “Truth and Science”; “Philosophy of Freedom”; “Goethe's World Concept” and “Views of the World and Life in the Nineteenth Century.”

Many other criticisms might be suggested. Any one who had read some of the writer's earlier works: “Views of the World and Life in the Nineteenth Century,” for instance, or a smaller work on Haeckel and his Opponents, might think it incredible that one and the same man could have written those books as well as the present work and also his already published “Theosophy.” “How,” he might ask, “can a man throw himself into the breach [pg xxvi] for Haeckel, and then, turn around and discredit every sound theory concerning monism that is the outcome of Haeckel's researches?” He might understand the author of this book attacking Haeckel “with fire and sword”; but it passes the limits of comprehension that, besides defending him, he should actually have dedicated “Views of the World and Life in the Nineteenth Century” to him. Haeckel, it might be thought, would have emphatically declined the dedication had he known that the author was shortly to produce such stuff as An Outline of Occult Science, with all its unwieldy dualism.

The writer of this book is of the opinion that one may very well understand Haeckel without being bound to consider everything else as nonsense which does not flow directly from Haeckel's own presentments and premises. The author is further of the opinion that Haeckel cannot be understood by attacking him with “fire and sword,” but by trying to grasp what he has done for science. Least of all does he hold those opponents of Haeckel to be in the right, against whom he has in his book, Haeckel and his Opponents, sought to defend the great naturalist; for surely, the fact of his having gone beyond Haeckel's premises by placing the spiritual conception of the world side by side with the merely natural one conceived by Haeckel, need be no reason for assuming that he was of one mind with the latter's opponents. Any one taking the trouble to look at the matter in the right light must see that the [pg xxvii] writer's recent books are in perfect accord with those of an earlier date.

But the author can also conceive of a critic who in general and offhand looks upon the presentations of this book as the out-pourings of a fantasy run wild or as dreamy thought-pictures. Yet all that can be said in this respect is contained in the book itself, and it is explicitly shown that sane and earnest thought not only can but must be the touch-stone of all the facts presented. Only one who submits what is here advanced to logical and adequate examination, such as is applied to the facts of natural science, will be in a position to decide for himself how much reason has to say in the matter.

After saying this much about those who may at first be inclined to take exception to this work, we may perhaps be permitted to address a few words to those on whose sympathetic attention we can rely. These will find all broad essentials contained in the first chapter, “Concerning the Nature of Occult Science.” A word, however, must here be added. Although this book deals with investigations carried beyond the confines of intellect limited to the world of the senses, yet nothing has been asserted except what can be grasped by any person possessed of unprejudiced reasoning powers backed by a healthy sense of truth, and who is at the same time willing to turn these gifts to the best account; and the writer emphatically wishes it to be understood that he hopes to appeal to readers who will not be content with merely accepting on “blind faith” the [pg xxviii] matters presented, but who will take the trouble to test them by the light of their own understanding and by the experiences of their own lives. Above all, he desires cautious readers, who will allow themselves to be convinced only by what can be logically justified. The writer is well aware that his work would be worth nothing were its value to rest on blind belief; it is valuable only in the degree to which it can be justified by unbiased reason. It is an easy thing for “blind faith” to confound folly and superstition with truth, and doubtless many, who have been content to accept the supersensible on mere faith, will be inclined to think that this book makes too great demands upon their powers of thought. It is not a question of merely making certain communications, but rather of presenting them in a manner consistent with a conscientious view of the corresponding plane of life; for this is the plane upon which the loftiest matters are often handled with unscrupulous charlatanism, and where knowledge and superstition come into such close contact as to be liable to be confused one with the other.

Any one acquainted with supersensual research will, on reading this book, be able to see that the author has sought to define the boundary line sharply between what can be communicated now from the sphere of supersensible cognition, and that which will be given out, at a later time, or at least, in a different form.