Transcriber’s Note In PROBLEM I, CHAPTER III, Section 45 (originally page 38), chemical formulas represent the numbers of atoms in a molecule with patterns like this: C_{114}. Throughout this eBook, pairs of underscores enclose italicized text, Small-caps text appears as ALL-CAPS, and pairs of equals signs enclose boldface text. Works by the same Author. =PROBLEMS OF LIFE AND MIND. The Foundations of a Creed.= Two Volumes. Octavo. Per volume, $3.00. CONTENTS: The Method of Science and its Applications to Metaphysics--The Rules of Philosophizing--Psychological Principles--The Limitations of Knowledge--The Principles of Certitude--From the Known to the Unknown--Matter and Force--Force and Cause--The Absolute in the Correlations of Feeling and Motion. =THE STORY OF GOETHE’S LIFE.= New Edition. One volume. 16mo. With Portrait. $1.50. *.* _For sale by all Booksellers. Sent, post-paid, on receipt of price by the Publishers,_ HOUGHTON, MIFFLIN & CO., BOSTON. THE PHYSICAL BASIS OF MIND. With Illustrations. _BEING THE SECOND SERIES_ OF PROBLEMS OF LIFE AND MIND. BY GEORGE HENRY LEWES. [Illustration: The Riverside Press.] BOSTON AND NEW YORK: HOUGHTON, MIFFLIN AND COMPANY. The Riverside Press, Cambridge. 1891. AUTHOR’S EDITION. _From Advance Sheets._ _The Riverside Press, Cambridge, Mass., U. S. A._ Printed by H. O. Houghton & Company. PREFACE. The title indicates that this volume is restricted to the group of material conditions which constitute the organism in relation to the physical world--a group which furnishes the data for one half of the psychologist’s quest; the other half being furnished by historical and social conditions. The Human Mind, so far as it is accessible to scientific inquiry, has a twofold root, man being not only an animal organism but an unit in the social organism; and hence the complete theory of its functions and faculties must be sought in this twofold direction. This conception (which has been declared “to amount to a revolution in Psychology”), although slowly prepared by the growing conviction that Man could not be isolated from Humanity, was first expounded in the opening volume of these _Problems of Life and Mind_; at least, I am not aware that any predecessor had seen _how_ the specially human faculties of Intellect and Conscience were products of social factors co-operating with the animal factors.