When, a score of years ago, I first read Hegel's Philosopkie der Geschichte, I resolved that, should I ever write a book, I would dispense with an introduction. I shall now keep, substantially, that self-made promise; and yet I feel myself necessitated to preface my work with a few words, in order that I may briefly explain to the public why I presume to ask its indulgent attention to another treatise upon an old subject, and in order that I may make due acknowledgment of my gratitude to two friends, who have rendered me invaluable service in the preparation of these volumes.<br><br>I believe it was Goethe who said that men should live before they write. It is, indeed, a serious thing to ask the world to read a book. It should never be done, unless the book answers a purpose not fulfilled, or not so well fulfilled, by some book already existing. The publication of a new book in the domain of Political Science is never justifiable unless it contains new facts; or a more rational interpretation, or a more scientific arrangement, of facts already known; or a new theory.<br><br>It is this consideration which has caused me to hesitate long before offering this work to the public, - so long that I have sometimes feared it would share the fate of Mr. Casaubon's Key. I cannot claim that it contains any facts before unknown. I believe that I advance, in some cases, a different interpretation of facts, and a different conclusion from facts, than have been, heretofore, presented.