HARVARD 1046*172 Entered, according to Act of Congress, in the year 1857, by In the Clerk's Office of the District Court of the District of Massachusetts. PRINTED BY GEORGE C. RAND & AVERY. STEREOTYPED BY THOMAS B. SMITH, 82 & 84 Beekman St.. N. Y. PREFACE. IF any apology were necessary for adding yet another to the numerous works on Mental Philosophy which have recently appeared, the circumstances that led to the preparation of the present volume may, perhaps, constitute that apology. Of When called, several years since, to the chair of Mental and Moral Philosophy, in this Institution, the text-books, then in use, seemed to me not well adapted to the wants of College students. Nor was it easy to make a change for the better. the works in this department, then generally in use in our Colleges, some presumed on a more extensive acquaintance with the science than most young men at this stage of education are likely to possess; others, again, erring on the opposite extreme, were deficient in thorough and scientific treatment; while most, if not all, were, at the best, incomplete, presenting but |