From the introduction: This is the re-issue of a book with a strange history; a book moreover not only entirely unknown, for reasons that will presently appear, to all but the meagrest minority, but one treating of a subject hitherto excluded from consideration by exponents of conventional learning. Whether even now men devoted professionally or otherwise to philosophy, divinity or science will give it the least attention is problematical. Be that as it may, it is believed that among those to whom the book and its subject-matter will be new there will be not a few who will accord it at least an interested and respectful notice, whilst many others who are already aware of the book's existence and the general tenor of its theme will welcome its re-issue and the fact that after nearly seventy years of suppression it now becomes generally accessible. In the interests of the book itself, and for the information of those whom it will now reach, it is desirable that something should be said of its authorship and previous history, the reasons for its suppression and its reappearance, and lastly of the subject of which it treats. This book is a high quality facsimile reprint of the 1918 edition.