The knowledge of most worth is first and foremost the knowledge of how to behave—a knowledge of social customs and usages. Any person totally ignorant in this regard would not escape imprisonment—perhaps I should say decapitation—for one day in any city of the world—say in London, in Pekin, in Timbuctoo, or in a _pueblo_ of Arizona. A knowledge of human customs and usages, next a knowledge of human views of Nature and man—these are of primordial necessity to an individual, and are means of direct self-preservation. The old trivium or threefold course of study at the university taught grammar, logic, and rhetoric—namely, (1) the structure of language, (2) the structure of mind and the art of reasoning, (3) the principles and art of persuasion. These may be seen at once to be lofty subjects and worthy objects of science. They will always remain such, but they are not easy for the child. In the course of mastering them he must learn to master himself and gain great intellectual stature. Pedagogy has wisely graded the road to these heights, and placed much easier studies at the beginning and also made the studies more various. Improvements in methods and in grading—devices for interesting the pupil—so essential to his self-activity, for these we have to thank the Educational Reformers. W. T. HARRIS. WASHINGTON, D. C., 1890. PREFACE TO EDITION OF 1868. “_It is clear that in whatever it is our duty to act, those matters also it is our duty to study._” These words of Dr. Arnold’s seem to me incontrovertible. So a sense of duty, as well as fondness for the subject, has led me to devote a period of leisure to the study of _Education_, in the practice of which I have been for some years engaged.