ways what it was and a study of the theme here to be presented is of perennial profit, alike in peace and war. The peculiar conditions of the time have generated so great a thirst for change and for the new that the thought of the wildest dreamer may be quickly accepted and absorbed as truth by a multitude of minds, to the undoing of many individual lives and the peril of society. Despite our remarkable advance in knowledge, nonsense is ever becoming bolder and more rampant: it is preeminently a time of fads and crazes, and the question as to how the people are to be brought to their senses grows urgent. Obviously, it should be our aim to quicken the critical faculty, to induce a habit of livelier and saner discrimination, and to this end we need a better knowledge of the mind's powers, limitations, and mechanism. This field of research has acquired much light in recent years, which should be applied to the bettering of the general thought and conduct. Such error as the reader may find in the book he should regard as further evidence for its main contention that—as everyone knows but continually forgets every presentation of truth is permeated with error. Absolute truth and absolute values are beyond our reach; yet we must form opinions and make for ourselves values. Wisdom requires that we think carefully before believing and that we estimate practical bearing with far-reaching caution before determining worth. Upon such a basis, the modification of present conditions means a true and continuing progress; the headlong rush, characteristic of our time, toward each new scheme of the visionary means catastrophe. Although the teaching of experience be uncertain and all knowledge imperfect, we have yet reasonable ground for incentive and inspiration, through which life may be made not only more tolerable but joyous. "Fooled thou must be, though wisest of the wise: WASHINGTON, D. C., December, 1919. W. D. McK. CONTENTS Expectations from the War-Credulity of the Time-Words instead of Action-The Mental Atmosphere-Inordinate Self-esteem-Spread of Knowledge-The General Super- ficiality-Instability of Opinion-Attitude toward the Degenerate and Training of Children-Self-teaching- PAGE The Child's Environment-Thought Seeks Externalization -Language-Conversation-The Newspaper-Books— The Novel-History-Biography-The Autobiography— Influence of a Book and its Merit-Max Müller-Very Erratic or Insane Authors-Weininger-Nietzsche-Crit- icism-Professional Disingenuity-Mysticism-Philos- tional Powers-Reasoning-Analogy-Induction-De- Its Control of Intellect-Feeling the Core of Man's Nature Fear-Misleading Influence of Feeling-Self- esteem and Sense of Inferiority-A Reason for Alcoholic Excess-The Internal Conflict-The Function of Play- Suggestion-Mental Fluctuations-Fatigue-Food and Drink, Alcohol, Chloral, Narcotics—Atmospheric Con- |