THE ORIGIN AND NATURE of the EMOTIONS Miscellaneous Papers BY GEORGE W. CRILE, M.D. PROFESSOR OF SURGERY, SCHOOL OF MEDICINE, WESTERN RESERVE UNIVERSITY VISITING SURGEON TO THE LAKESIDE HOSPITAL, CLEVELAND EDITED BY AMY F. ROWLAND, B. S. PREFACE IN response to numerous requests I have brought together into this volume eight papers which may serve as a supplement to the volumes previously published[*] and as a preface to monographs now in preparation. [*] Surgical Shock, 1899; Surgery of the Respiratory System, 1899; Problems Relating to Surgical Operations, 1901; Blood Pressure in Surgery, 1903; Hemorrhage and Transfusion, 1909; Anemia and Resuscitation, 1914; and Anoci-association, 1914 (with Dr. W. E. Lower). In the first of these addresses, the Ether Day Address, delivered at the Massachusetts General Hospital in October, 1910, I first enunciated the Kinetic Theory of Shock, the key to which was found in laboratory researches and in a study of Darwin's "Expression of the Emotions in Man and in Animals," whereby the phylogenetic origin of the emotions was made manifest and the pathologic identity of surgical and emotional shock was established. Since 1910 my associates and I have continued our researches through-- (a) Histologic studies of all the organs and tissues of the body; (b) Estimation of the H-ion concentration of the blood in the emotions of anger and fear and after the application of many other forms of stimuli; (c) Functional tests of the adrenals, and (d) Clinical observations. It would seem that if the striking changes produced by fear and anger and by physical trauma in the master organ of the body-- the brain--were due to WORK, then we should expect to find corresponding histologic changes in other organs of the body as well. We therefore examined every organ and tissue of the bodies of animals which had been subjected to intense fear and anger and to infection and to the action of foreign proteins, some animals being killed immediately; some several hours after the immediate effects of the stimuli had passed; some after seances of strong emotion had been repeated several times during a week or longer. The examination of all the tissues and organs of these animals showed changes in three organs only, and with few exceptions in all three of these organs--the brain, the adrenals, and the liver. The extent of these changes is well shown by the photomicrographs which illustrate the paper on "The Kinetic System" which is included in this volume. This paper describes many experiments which show that the brain, the adrenal, and the liver play together constantly and that no one of these organs--as far at least as is indicated by the histologic studies--can act without the co-operation of the other two.