their appearance, we can trace a gradual closing in from all sides, as it were, upon the great generalizations which were by and by to fall into their places as integral parts of a coherent system of thought. As a matter of fact, these years may be regarded, from the point of view of subsequent achievement, as years of special and methodical training; and these essays, diverse as they are in form and matter, as separate and tentative contributions toward the treatment of various isolated phenomena which were ultimately to be taken up in their interrelations and dealt with in the mass. It would be impossible here to subject these essays one by one to anything like close analysis, even if it would materially further our present purpose to do so. But a few words must be devoted to their general drift and character; and, should one or two of them be made the subjects of special mention, it will not be because these are to be considered the most important in themselves, but simply because they are the most important for the object which at the moment I have in view.
Probably the points which would most strike any one reading these essays casually and for the first time would be their strong grasp upon deep-lying principles, and their extraordinary originality. On every page they reveal, be the subject what it may, an astonishing independence of thought, and an absolute freedom from all trace of traditional methods and ideas. It was this freshness of treatment and firmness of touch which perhaps most attracted the attention of thoughtful readers when they were first published — for the most part anonymously — in the pages of the various English magazines and reviews. But, turning back to them to-day and regarding them in their mutual relations (as we are able to do now that they have long since been available in a collected and permanent form), we are impressed by something beyond the depth, clearness, and vigor of mind to which they everywhere bear witness. And that something is the essential unity of their thought, the oneness of idea which is throughout seen to underlie and inform the extraordinary diversity of materials with which they deal. It matters not whether the author is concerned with the moot questions of physiology and psychology; or with the intrinsic principles of a correct literary style; or with the changes of the sidereal system; or with ill-timed and hasty political panaceas; or with curiosities of social manners and behavior: all these subjects are systematically approached from one point of view; all are made to cluster about and find interpretation in one dominant hypothesis. And what is this hypothesis? What is this great cardinal doctrine which is thus made to weld together subjects so diverse and even so incongruous that on any merely superficial examination they would never be supposed to possess anything in common? It need hardly be said that it is