PREFACE A SMALL pamphlet, bearing the title of the present work, was a few years ago put forward by the author, and contained the germ of the essay now offered to the public. The principles which it enunciated are more fully explained, and are more extensively carried out in the following pages than were allowed by the limits of the former publication. Much matter that is altogether new has, moreover, been here introduced, and some topics are discussed which were not embraced by the pamphlet in question. On the other hand, a portion of the matter contained in the previous work has been omitted in the present treatise. |