This book, while bringing to bear on the problem of knowledge the more recent points of view, both psychological and philosophical, aims chiefly at helping the reader in the culture and practical uses of the mental life. Thus it considers not only the nature and guaranties of knowledge, but especially how knowledge may be used to attain its most important ends. These are the ideals and the behavior that have value. Without being controversial, it furnishes material for criticism of the errors and half-truths of Pragmatism and other current theories as to the meaning and worth of Truth. Its conclusions lie in "the middle of the road," between the extremes of intellectual over-confidence or an easy credulousness and excessive skepticism or agnostic despair. Inasmuch as all knowledge involves the higher sentiments and the activities of "free will' its attainment and culture become a matter of personal obligation and moral concernment. In this way this Treatise serves as an Introduction for those which are to follow, and which will treat of Duty, Faith, and Hope, in further defense of a consistent system of rationalism in opinion and in conduct.For such ... as are seeking a satisfying answer to the inquiry propounded by this volume a veteran thinker here cuts an easily traveled path through the mazes of the subject, clearing it of entanglements, and steadily keeping in view its issues in practical value for the rational conduct of life. - "The Outlook. "The man of learning who puts into a little book his best and most availably useful thought, so simply expressed that all who are intelligent, with or without technical training, may understand, does an eminently good thing.... Dr. Ladd approaches his subject as one seeking for practical light and leading. Illuminatingly he discusses the question of the limitations of human knowledge, the effects of heredity and of environment, including the opinions of others, everywhere deepening the significance of those lessons which common sense and experience teach with more or less thoroughness to the virtuous and the intelligent. Analyzing the process by which we know, he sums up his results in the notable saying that "knowledge is a matter of the entire man - the real knower is the whole self, not as a ' naked mind, ' but as a living soul." - "North American Review. "These far reaching questions, as we have intimated, are answered by Professor Ladd from the point of view which he has reached in his own long course of reflective thinking. For the most part his results are not only wholesome and constructive in themselves, but they are stated in moderate terms. Later novelties in the epistemological field are also taken into account, ... the style is planned for the comprehension of the knower little versed in technical forms. Without writing down to the level of the plain man, Professor Ladd has been at pains to phrase his conclusions as simply as may be. - "The Philosophical Review," March, 1915.