There are, we know, two main functions in the sexual relationship, or what in the biological sense we term “marriage,” among civilised human beings, the primary physiological function of begetting and bearing offspring and the secondary spiritual function of furthering the higher mental and emotional processes.  These are the main functions of the sexual impulse, and in order to understand any further object of the sexual relationship—­or even in order to understand all that is involved in the secondary object of marriage—­we must go beyond conscious motives and consider the nature of the sexual impulse, physical and psychic, as rooted in the human organism.

The human organism, as we know, is a machine on which excitations from without, streaming through the nerves and brain, effect internal work, and, notably, stimulate the glandular system.  In recent years the glandular system, and especially that of the ductless glands, has taken on an altogether new significance.  These ductless glands, as we know, liberate into the blood what are termed “hormones,” or chemical messengers, which have a complex but precise action in exciting and developing all those physical and psychic activities which make up a full life alike on the general side and the reproductive side, so that their balanced functions are essential to wholesome and complete existence.  In a rudimentary form these functions may be traced back to our earliest ancestors who possessed brains.  In those times the predominant sense for arousing the internal mental and emotional faculties was that of smell, the other senses being gradually evolved subsequently, and it is significant that the pituitary, one of the chief ductless glands active in ourselves to-day, was developed out of the nervous centre for smell in conjunction with the membrane of the mouth.  The energies of the whole organism were set in action through stimuli arising from the outside world by way of the sense of smell.  In process of time the mechanism has become immensely elaborated, yet its healthy activity is ultimately dependent on a rich and varied action and reaction with the external world.  It is becoming recognised that the tendency to pluri-glandular insufficiency, with its resulting lack of organic harmony and equilibrium, can be counteracted by the physical and psychic stimuli of intimate contacts with the external world.  In this action and reaction, moreover, we cannot distinguish between sexual ends and general ends.  The activities of the ductless glands and their hormones equally serve both ends in ways that cannot be distinguished.  “The individual metabolism,” as a distinguished authority in this field has expressed it, “is the reproductive metabolism."[18] Thus the establishment of our complete activities as human beings in the world is aided by, if not indeed ultimately dependent upon, a perpetual and many-sided play with our environment.

[18] W. Blair Bell, The Sex-Complex, 1920, p. 108.  This book is a cautious and precise statement of the present state of knowledge on this subject, although some of the author’s psychological deductions must be treated with circumspection.