It is now clear, therefore, why the evacuation theory of the sexual impulse must necessarily be partial and inadequate. It leaves out of account the whole of the phenomena connected with tumescence, and those phenomena constitute the most prolonged, the most important, the most significant stage of the sexual process. It is during tumescence that the whole psychology of the sexual impulse is built up; it is as an incident arising during tumescence and influencing its course that we must probably regard nearly every sexual aberration. It is with the second stage of the sexual process, when the instinct of detumescence arises, that the analogy of evacuation can alone be called in. Even here, that analogy, though real, is not complete, the nervous element involved in detumescence being out of all proportion to the extent of the evacuation. The typical act of evacuation, however, is a nervous process, and when we bear this in mind we may see whatever truth the evacuation theory possesses. Beaunis classes the sexual impulse with the "needs of activity," but under this head he coordinates it with the "need of urination." That is to say, that both alike are nervous explosions. Micturition, like detumescence, is a convulsive act, and, like detumescence also, it is certainly connected with cerebral processes; thus in epilepsy the passage of urine which may occur (as in a girl described by Gowers with minor attacks during which it was emitted consciously, but involuntarily) is really a part of the process.[[48]]
There appears, indeed, to be a special and intimate connection between the explosion of sexual detumescence and the explosive energy of the bladder; so that they may reinforce each other and to a limited extent act vicariously in relieving each other's tension. It is noteworthy that nocturnal and diurnal incontinence of urine, as well as "stammering" of the bladder, are all specially liable to begin or to cease at puberty. In men and even infants, distention of the bladder favors tumescence by producing venous congestion, though at the same time it acts as a physical hindrance to sexual detumescence[[49]]; in women—probably not from pressure alone, but from reflex nervous action—a full bladder increases both sexual excitement and pleasure, and I have been informed by several women that they have independently discovered this fact for themselves and acted in accordance with it. Conversely, sexual excitement increases the explosive force of the bladder, the desire to urinate is aroused, and in women the sexual orgasm, when very acute and occurring with a full bladder, is occasionally accompanied, alike in savage and civilized life, by an involuntary and sometimes full and forcible expulsion of urine.[[50]] The desire to urinate may possibly be, as has been said, the normal accompaniment of sexual excitement in women (just as it is said to be in mares; so that the Arabs judge that the mare is ready for the stallion when she urinates immediately on hearing him neigh). The association may even form the basis of sexual obsessions.[[51]] I have elsewhere shown that, of all the influences which increase the expulsive force of the bladder, sexual excitement is the most powerful.[[52]] It may also have a reverse influence and inhibit contraction of the bladder, sometimes in association with shyness, but also independently of shyness. There is also reason to suppose that the nervous energy expended in an explosion of the tension of the sexual organs may sometimes relieve the bladder; it is well recognized that a full bladder is a factor in producing sexual emissions during sleep, the explosive energy of the bladder being inhibited and passing over into the sexual sphere. Conversely, it appears that explosion of the bladder relieves sexual tension. An explosion of the nervous centers connected with the contraction of the bladder will relieve nervous tension generally; there are forms of epilepsy in which the act of urination constitutes the climax, and Gowers, in dealing with minor epilepsy, emphasizes the frequency of micturition, which "may occur with spasmodic energy when there is only the slightest general stiffness," especially in women. He adds the significant remark that it "sometimes seems to relieve the cerebral tension,"[[53]] and gives the case of a girl in whom the aura consisted mainly of a desire to urinate; if she could satisfy this the fit was arrested; if not she lost consciousness and a severe fit followed.
If micturition may thus relieve nervous tension generally, it is not surprising that it should relieve the tension of the centers with which it is most intimately connected. Sérieux records the case of a girl of 12, possessed by an impulse to masturbation which she was unable to control, although anxious to conquer it, who only found relief in the act of urination; this soothed her and to some extent satisfied the sexual excitement; when the impulse to masturbate was restrained the impulse to urinate became imperative; she would rise four or five times in the night for this purpose, and even urinate in bed or in her clothes to obtain the desired sexual relief.[[54]] I am acquainted with a lady who had a similar, but less intense, experience during childhood. Sometimes, especially in children, the act of urination becomes an act of gratification at the climax of sexual pleasure, the imitative symbol of detumescence. Thus Schultze-Malkowsky describes a little girl of 7 who would bribe her girl companions with little presents to play the part of horses on all fours while she would ride on their necks with naked thighs in order to obtain the pleasurable sensation of close contact. With one special friend she would ride facing backward, and leaning forward to embrace her body impulsively, and at the same time pressing the neck closely between her thighs, would urinate.[[55]] Féré has recorded the interesting case of a man who, having all his life after puberty been subject to monthly attacks of sexual excitement, after the age of 45 completely lost the liability to these manifestations, but found himself subject, in place of them, to monthly attacks of frequent and copious urination, accompanied by sexual day-dreams, but by no genital excitement.[[56]] Such a case admirably illustrates the compensatory relation of sexual and vesical excitation. This mutual interaction is easily comprehensible when we recall the very close nervous connection which exists between the mechanisms of the sexual organs and the bladder.
Nor are such relationships found to be confined to these two centers; in a lesser degree the more remote explosive centers are also affected; all motor influences may spread to related muscles; the convulsion of laughter, for instance, seems to be often in relation with the sexual center, and Groos has suggested that the laughter which, especially in the sexually minded, often follows allusions to the genital sphere is merely an effort to dispel nascent sexual excitement by liberating an explosion of nervous energy in another direction.[[57]] Nervous discharges tend to spread, or to act vicariously, because the motor centers are more or less connected.[[58]] Of all the physiological motor explosions, the sexual orgasm, or detumescence, is the most massive, powerful, and overwhelming. So volcanic is it that to the ancient Greek philosophers it seemed to be a minor kind of epilepsy. The relief of detumescence is not merely the relief of an evacuation; it is the discharge, by the most powerful apparatus for nervous explosion in the body, of the energy accumulated and stored up in the slow process of tumescence, and that discharge reverberates through all the nervous centers in the organism.
"The sophist of Abdera said that coitus is a slight fit of epilepsy, judging it to be an incurable disease." (Clement of Alexandria, Pædagogus, bk. ii, chapter x.) And Cœlius Aurelianus, one of the chief physicians of antiquity, said that "coitus is a brief epilepsy." Féré has pointed out that both these forms of nervous storm are sometimes accompanied by similar phenomena, by subjective sensations of sight or smell, for example; and that the two kinds of discharge may even be combined. (Féré, Les Epileptiques, pp. 283-84; also "Exces Vénériens et Epilepsie," Comptes-rendus de la Société de Biologie, April 3, 1897, and the same author's Instinct Sexuel, pp. 209, 221, and his "Priapisme Epileptique," La Médecine Moderne, February 4, 1899.) The epileptic convulsion in some cases involves the sexual mechanism, and it is noteworthy that epilepsy tends to appear at puberty. In modern times even so great a physician as Boerhaave said that coitus is a "true epilepsy," and more recently Roubaud, Hammond, and Kowalevsky have emphasized the resemblance between coitus and epilepsy, though without identifying the two states. Some authorities have considered that coitus is a cause of epilepsy, but this is denied by Christian, Strümpell, and Löwenfeld. (Löwenfeld, Sexualleben und Nervenleiden, 1899, p. 68.) Féré has recorded the case of a youth in whom the adoption of the practice of masturbation, several times a day, was followed by epileptic attacks which ceased when masturbation was abandoned. (Féré, Comptes-rendus de la Socitété de Biologie, April 3, 1897.)
It seems unprofitable at present to attempt any more fundamental analysis of the sexual impulse. Beaunis, in the work already quoted, vaguely suggests that we ought possibly to connect the sexual excitation which leads the male to seek the female with chemical action, either exercised directly on the protoplasm of the organism or indirectly by the intermediary of the nervous system, and especially by smell in the higher animals. Clevenger, Spitzka, Kiernan, and others have also regarded the sexual impulse as protoplasmic hunger, tracing it back to the presexual times when one protozoal form absorbed another. In the same way Joanny Roux, insisting that the sexual need is a need of the whole organism, and that "we love with the whole of our body," compares the sexual instinct to hunger, and distinguishes between "sexual hunger" affecting the whole system and "sexual appetite" as a more localized desire; he concludes that the sexual need is an aspect of the nutritive need.[[59]] Useful as these views are as a protest against too crude and narrow a conception of the part played by the sexual impulse, they carry us into a speculative region where proof is difficult.
We are now, however, at all events, in a better position to define the contents of the sexual impulse. We see that there are certainly, as Moll has indicated, two constituents in that impulse; but, instead of being unrelated, or only distantly related, we see that they are really so intimately connected as to form two distinct stages in the same process: a first stage, in which—usually under the parallel influence of internal and external stimuli—images, desires, and ideals grow up within the mind, while the organism generally is charged with energy and the sexual apparatus congested with blood; and a second stage, in which the sexual apparatus is discharged amid profound sexual excitement, followed by deep organic relief. By the first process is constituted the tension which the second process relieves. It seems best to call the first impulse the process of tumescence; the second the process of detumescence.[[60]] The first, taking on usually a more active form in the male, has the double object of bringing the male himself into the condition in which discharge becomes imperative, and at the same time arousing in the female a similar ardent state of emotional excitement and sexual turgescence. The second process has the object, directly, of discharging the tension thus produced and, indirectly, of effecting the act by which the race is propagated.
It seems to me that this is at present the most satisfactory way in which we can attempt to define the sexual impulse.