PREFACE. I A DETAILED account of the origin of this work, perhaps, would be of little interest; but it may be permissible to state that the subject has occupied my mind for a period of twenty-three years. It has, however, to be noted that during all this time I was also employed at other kinds of work, by which I earned a livelihood. The form which the work at last assumed did not at once present itself to my mind; it rather arose out of other inquiries in which I was deeply interested. worked for some time before I became fully aware of the original sources of information; while for long after I had become aware of the most valuable and original materials of history relating to my subject, I had often extreme difficulty in finding access to them for the purpose of my researches. The libraries of mutual improvement societies and mechanics' institutions were utterly insufficient. But it was then chiefly that I prepared myself by a course of philosophic study, embracing metaphysics, psychology, logic, ethics, and politics, carefully reading hundreds of works on these matters, both ancient and modern. But it was only after I obtained the privilege of |