The whole study of characterology or the motivation of conduct is extremely new, and there are many indications of immense values in uncovered fields. Some appreciation of this fact may be gained from the following pages which show the possibility of tracing one form of behavior to its source. We have laid under contribution practically the entire literature on the subject, almost none of which is in English, and also the thorough-going longitudinal case studies made by the Juvenile Psychopathic Institute of Chicago. In the latter material there was found much of value bearing upon the subject of lying, false accusation, and swindling of pathological character. Our institute, later taken over officially by the Juvenile Court of Cook County, was for five years maintained upon a foundation provided by Mrs. W. F. Dummer. WILLIAM HEALY MARY TENNEY HEALY WINNETKA, ILL. June, 1915. CONTENTS CHAPTER EDITORIAL ANNOUNCEMENT PREFACE I. INTRODUCTION II. PREVIOUS STUDIES III. CASES OF PATHOLOGICAL LYING AND SWINDLING IV. CASES OF PATHOLOGICAL ACCUSATION V. CASES OF PATHOLOGICAL LYING IN BORDER-LINE MENTAL TYPES VI. CONCLUSIONS INDEX OF AUTHORS INDEX OF TOPICS PATHOLOGICAL LYING, ACCUSATION, AND SWINDLING CHAPTER I INTRODUCTION Through comparison of the literature on pathological lying with our own extensive material we are led to perceive the insistent necessity for closer definition of the subject than has been heretofore offered. Reasons for excluding types earlier described as pathological liars will be found throughout our work. Better definition goes hand in hand with better understanding, and it is only natural that formal, detailed contemplation of the subject should lead to seeing new lines of demarcation. Definition: Pathological lying is falsification entirely disproportionate to any discernible end in view, engaged in by a person who, at the time of observation, cannot definitely be declared insane, feebleminded, or epileptic. Such lying rarely, if ever, centers about a single event; although exhibited in very occasional cases for a short time, it manifests itself most frequently by far over a period of years, or even a life time. It represents a trait rather than an episode. Extensive, very complicated fabrications may be evolved. This has led to the synonyms:--mythomania; pseudologia phantastica.