The present work was the first really objective Criminal Psychology which dealt with the mental states of judges, experts, jury, witnesses, etc., as well as with the mental states of criminals. And a study of the former is just as needful as a study of the latter. The need has fortunately since been recognized and several studies of special topics treated in this book--e.g. depositions of witnesses, perception, the pathoformic lie, superstition, probability, sensory illusions, inference, sexual differences, etc.--have become the subjects of a considerable literature, referred to in our second edition. I agreed with much pleasure to the proposition of the American Institute of Criminal Law and Criminology to have the book translated. I am proud of the opportunity to address Americans and Englishmen in their language. We of the German countries recognize the intellectual achievements of America and are well aware how much Americans can teach us. I can only hope that the translation will justify itself by its usefulness to the legal profession. HANS GROSS. TRANSLATOR’S NOTE. The present version of Gross’s Kriminal Psychologie differs from the original in the fact that many references not of general psychological or criminological interest or not readily accessible to English readers have been eliminated, and in some instances more accessible ones have been inserted. Prof. Gross’s erudition is so stupendous that it reaches far out into texts where no ordinary reader would be able or willing to follow him, and the book suffers no loss from the excision. In other places it was necessary to omit or to condense passages. Wherever this is done attention is called to it in the notes. The chief omission is a portion of the section on dialects. Otherwise the translation is practically literal. Additional bibliography of psychological and criminological works likely to be generally helpful has been appended. CONTENTS. PAGE GENERAL INTRODUCTION TO THE MODERN CRIMINAL SCIENCE SERIES v INTRODUCTION TO THE ENGLISH VERSION ix AUTHOR’S PREFACE TO THE AMERICAN EDITION xiii TRANSLATOR’S NOTE xiv INTRODUCTION 1 PART I. THE SUBJECTIVE CONDITIONS OF EVIDENCE (THE MENTAL ACTIVITIES OF THE JUDGE) 7 TITLE A. CONDITIONS OF TAKING EVIDENCE 7 Topic 1. METHOD 7 § 1 (_a_) General Considerations 7 § 2 (_b_) The Method of Natural Science 9 Topic 2. PSYCHOLOGIC LESSONS 14 § 3 (_a_) General Considerations 14 § 4 (_b_) Integrity of Witnesses 16 § 5 (_c_) Correctness of Testimony 18