( Originally Published 1940 )

ERECTION is the most prominent manifestation of the sexual life, but it can occur only if, firstly, a certain degree of congestion, and, secondly, a certain degree of irritability of the central nervous system, are present, two preliminary conditions which mutually support each other very effectively.

What causes the congestion? In order to answer this question we need only refer once more to our parallel between the urinary and seminal secretions.

We have not forgotten the case of the child with such a strong desire to make water, who was denied the opportunity; here we see so plainly the secretory antagonism with all its accompanying symptoms, so congestive and then so spasmodic!

I beg the reader carefully to recall this familiar picture of a child suffering; it is a picture of suffering mankind, wrestling with its bodily needs. Especially is it a picture of sexual suffering with its congestive excitement; and I can only imagine one other picture that can equal it : that is the ecstasy of voluptuousness, when at last the natural desire can be gratified?

If we can appreciate this picture, we immediately have the answer to the question how it is possible for such an apparently insignificant function as the voiding of semen to excite so much congestion. As we have seen in the last chapter but one, the embryonic origin gives the predisposition; but sometimes the resistance occasions such marked congestion as to prevent ejaculation. For unfortunately the secretion of semen is a function which always meets with strong resistance. Remember that this thick, viscous mucous emulsion must be forced through two capillary tubes in order to reach the urethra. What resistance! Is it then surprising that all the symptoms of congestion, which appear only exceptionally in the secretion of urine, should regularly accompany the secretion of semen? Such colossal resistance which can never once be abated! So in this case the impulse must be increased to its extreme limits before so great a resistance can be overcome. The seminal secretion dominates the entire circulation of our blood; it makes us blush only to think of it.

And furthermore a man ought to think himself lucky to get off with a simple congestion; it is much worse for women, for in their sexual life they suffer from repeated haemorrhages, first in the tissues of the ovary, then in menstruation, and then a great deal at child-birth.

Every child who has an excessive desire to urinate shows the congestion principally in his face, and accompanying symptom of the cerebral congestion caused by the psychic strain on the will; for a congestion always occurs locally where an organ is strained to the extreme.

With the seminal secretion it is essentially the powerful local resistance that calls forth local congestion, through which, as we explained in Chapter 10, a maximum erection occurs, as soon as the external occlusory muscles are drawn into the antagonism by sympathy.

In some exceptional cases an erection occurs when urine is voided. I remember the case of an infant only a couple of months old, that is, too young for any psychic influence or training to be concerned. His parents paid great attention to hygienic questions and had kept him always scrupulously clean and not too tightly clothed. "I always know," said his mother, "when he wants to urinate." "How can you know that?" I asked. "I can see it," was the answer, "when his little member swells. Then I hold him over the chamber till he passes urine." So in the case of this inexperienced little boy, the normal muscular antagonism that accompanies a desire to urinate is sufficient to act as a local stimulus and occasions an erection, although only a childish one.

So we see that erection, viewed theoretically, is not by any means confined to the sexual life. As we have already shown in Chapter 10, it is ultimately a function of the external occlusory musculature, as soon as this is sympathetically affected by the antagonism of one of the three excretory systems. Every adult male knows how strong an erection may be produced in the course of the night by an overcharged intestine or bladder; and how frequently, when waking in the morning, erection, perhaps accompanied by erotic dreams, is a warning to empty the bladder. In advanced years a man is often proud of his virile powers, and they suddenly disappear just as he wants to utilise them. And then the attempt to approach the object of his desire banishes for an instant the impulse to urinate, and the whole illusion disappears. This mockery, and, when it happens frequently, this misery, might be spared, if one properly understood the facts of the case.

And erections in childhood show us more unmistakably than anything else that erections may occur without any pressure of semen. At this age there is no pressure of semen at all. That at this age it is only a childish erection, depends not only on absence of any distension of the seminal vesicles, but also on the fact that the spongy connective tissue is not yet very rigid, and that the appropriate organochemical substances have not yet increased the irritability of the nervous system. But still it is an erection.

Both stimuli often act together: the urinary and seminal pressures. That this never leads to an unwelcome mixing of both secretions, depends on the fact that in man each of these two functions precludes the other (see chapter 18). This is not so in woman. I remember one case of a grown up young girl of good family who was rather stupid. She was always trying to escape from her parents' home to have intercourse with young fellows. This led her also to masturbate and wet the bed. In youths the contrary is often observed, they cease wetting the bed on reaching the age of puberty.

An erection is more rarely produced by intestinal antagonism; but I have seen such cases produced by sudden expulsion of intestinal gases.

But in the first bloom of life, the sexual impulse is so overpowering that we really get the impression that erection is exclusively a sexual function. In this period of our lives it is really the sexual impulse that acts as the causal factor in the vast majority of cases. This should not surprise us. Ultimately it seems to depend on the lumen of the excretory canal, whether or not the antagonism shall assume the spasmodic character which is essential for the production of erection. The frequency of erection is in inverse proportion to the lumen of the excretory canal. So all the above-cited experiences bear witness, and we are now able to see why in this respect the pressure of the semen has the lion's share, if not the monopoly.

From this principle it will also be evident why the erectile function must occupy so much more modest a place in the female. The female genital canal is typically characterised not by narrowing, but by widening. The female urethra is also less complicated and wider than in man. Only the intestinal canal is of the same diameter in both sexes.

So far we have only dealt with the increase in the force of the blood stream, as it is occasioned by the muscular antagonism. So as to avoid as far as possible complicating the question, I have not yet touched on the active role played by the central nervous system, a role which is so important not only in the spiritual side of love, but also in the more material mechanism of erection. For the production of an erection, a strongly reacting central nervous system is required to serve as the connecting-link of the reflex.

The principle is sufficiently familiar. When, prompted by a stimulating sensation, our muscles begin to move, this takes place with the rapidity of lightning, yet the process is not at all simple. In most cases in order to produce this action the message must go a long way round, just as when we send a telegram; first to the central office, and then on to the destination. In this way a sensation is transmitted over the sensory nerves to the central nervous system (brain or spinal cord) and then back to the group of muscles involved, which then contract.

In and for itself alone this digression would have no significance, but on this complicated circuit not only can a stimulus influence many side-lines and become combined with other mental pictures, but it may also, no matter how weak it was at first, be immensely strengthened. For all nerve cells, like all the other cells, have the power of storing up energy. In mechanical work as a rule the newly formed energy is instantly used up, because an immediate result is demanded. But cell-life never acts in such haste. Here, by the absorption of nutriment, energy is slowly but unceasingly stored up. So too in the cells of the central nervous system, as soon as the cells are set in action, e.g., when a group of muscles is to be brought into reflex action, either when a group of skeletal muscles must carry out bodily movements, or smooth muscles must move the intestines, or the blood pressure must be regulated by increased heart action or arterial contraction.

So to a great degree it depends upon the normal sensibility and on the reserve of energy in our central nervous system, how rapidly, correctly, and powerfully we are accustomed to react to all influences, and how smoothly all our functions can be performed.

It is also an indispensable condition for the production of a powerful erection that our central nervous system should possess great sensibility and a store of energy.

As has been abundantly proved by Steinach's experiments (see chapter 4), it is the organochemical substances secreted by our testes or ovaries which produce this increased sensibility at puberty. If, however, through advancing years, this sensibility is greatly reduced and the seminal tension not so imperious, it is then almost entirely during sleep (see chapters 35 and 36) that the mental energies may be concentrated without disturbing influences, and that an erection may occur. In this connection we understand still better why in the bloom of our sexual life, it is precisely in our sleep that we are overtaken by emissions, and why it is in the intoxication of love that sexual passion can rise to such heights.

Owing to the changeable character of our central nervous system it often happens that the most trifling causes may lead to the most powerful excitement, and also the most trivial stimulus cause the strongest erection. Now we may better understand why our whole nervous system and especially all our sexual impulses are continually so capricious, so changeable and so uncertain.

And now it will be clear to us how, in this complicated circuit all kinds of side influences can affect us, either accelerating or inhibiting, especially the psychic influences to which we have already referred, when we stated that the special alarm-signal, the erection, which should theoretically only be the result of an overfilled reservoir, may be aroused at other times by other stimuli, such as a mental image.

It is still more important that the nerve-paths that we have described, represent a link between the spiritual and the material life, by means of which the most beautiful interchange can take place. One thing in the sexual province is most surprising, and that is that while the congestive stimulus at the lower pole of the body awakens the soul, through the spiritual sphere this passion may be turned into love.

The higher the stage at which we stand in the history of the evolution of the species, the more complicated these nerve-paths become; and so we have ultimately arrived at the point where we feel spiritual love to be something far more precious that its physical basis.

Because our brain possesses such a number of complicated nerve-paths, the mental energy can if necessary be diverted into quite other channels, particularly into paths which calm and soothe the sexual excitement. Every stimulus in other sections of the brain, or in other portions of the body, and every congestion in other brain centres or other parts of the body is capable of exerting a restraining influence on our sexual impulse. This constitutes one of the most important factors in self-control.

1 As a contrast to these two pictures of youth, let us think of the senile symptoms occurring in advanced age, when, as a consequence of paralysis of the antagonistic resistance, semen escapes unnoticed and unrestrained. Here voluptuous sensations are out of the question.