first study in the volume, that our knowledge of the physiological
mechanism of the sexual instinct has been revolutionized during recent
years. This is due to the investigations that have been made, and the
deductions that have been built up, concerning the part played by
hormones, or internal secretions of the ductless glands, in the physical
production of the sexual instinct and the secondary sexual characters. The
conception of the psychology of the sexual impulse here set forth, while
correlated to terms of a physical process of tumescence and detumescence,
may be said to be independent of the ultimate physiological origins of
that process. But we cannot fail to realize the bearing of physiological
chemistry in this field; and the doctrine of internal secretions, since it
may throw light on many complex problems presented by the sexual instinct,
is full of interest for us.

HAVELOCK ELLIS.

June, 1913.




PREFACE TO FIRST EDITION.


The present volume of _Studies_ deals with some of the most essential
problems of sexual psychology. The _Analysis of the Sexual Impulse_ is
fundamental. Unless we comprehend the exact process which is being worked
out beneath the shifting and multifold phenomena presented to us we can
never hope to grasp in their true relations any of the normal or abnormal
manifestations of this instinct. I do not claim that the conception of the