How The Human Sex Organs And The Brain Developed
( Originally Published 1940 )
The previous chapter took us back to a primeval period which we can scarcely now conceive, the long forgotten period when sexual life first dawned. Countless species of animals and plants have evolved since that far off time, and count-less species have died out in the course of the ages. At Iast the vertebrate animals were produced and in them the intellect has developed to an astonishing degree; a dangerous competitor for the sexual life!
Because these two systems are so diametrically opposed and have such an enormous influence on each other, we shall devote a special chapter to their mutual relations.
For most of us, when we study the doctrine of evolution, the pleasing moral of the story is briefly this: mankind stands in the highest rank, and it is by means of our higher mental development that we have accomplished so much on earth, and each of us can accomplish so much in the world, if only the sexual system does not rob him of his reason and ruin him.
In this chapter we shall enquire if this comparative evolution of the two chief factors of our life is really correct, and if it is not rather the fact that our mental life and our sexual life are the two central points of our existence both equally important for our happiness and both of equal value for our evolution; only they must maintain equilibrium between themselves.
Of course when we speak of the evolution of species, we must give to the higher development of our brain the honour that is due to it. By this sign we have conquered! d so we have become the "homo sapiens." After all, evolution is first and foremost a question of heredity, so it is certainly quite evident that the higher development of our sexual function is a no less important factor of our evolution; and who knows what may not be accomplished in the future by the ennobling of this function! In the struggle fox existence we have won through mostly by the antagonistic and alternating effects of the development of the brain and the development of sex, and we hope that this will continue to play 'an increasingly important part.
In the succeeding generations of the species the functions of the brain and of the sexual organs have not only developed in their numerous aspects, but they have always supported and stimulated each other more and more thoroughly. The two functions reach the apex of their development in every individual at the same age. The more beautifully the one forms, the finer will be the development of the other. We have all been struck more than once with the simultaneous occurrence of unimportance in the one with unimportance in the other respect; and the association of inspiration in the one respect with inspiration in the other. Numbers of celebrated men and women might be mentioned in this connection. So with regard to Saint Augustine it cannot be denied that the ardour of his religious belief and his African sexual temperament represent the two opposite sides of his character and cannot be considered apart!
We cannot but be amazed at the extraordinary sensitiveness of our brain cells, which are so specialised for sensibility; but we must be equally astonished at the extraordinary plasticity of the reproductive cells, which can give rise to an entirely new individual. On the one side cells of a creative genius, and on the other, cells that can really give rise to another generation.
Still better shall we be able to weigh the values of the two great powers of our existence, if we first see what evolution has to teach us in this respect, so that we get some insight into the manner in which the two poles of our body have so widely differentiated, with mutual division of labour.
In the foregoing chapter we studied the history of sexual evolution of vegetative growth, how it has gradually modified its type under the influence of the sexual.
Only the sexual life remains unchanged in its essential principles. Pollination and fertilisation are almost identical; each of them merely a transfer of single cells, characteristic of the sexual life from the first. The vegetative growth, however, has undergone a complete metamorphosis under this sexual influence; it has been forced to adapt itself to the sexual.
And so the whole history of evolution has gradually come to symbolically represent an apotheosis of the god Cupid. The little rascal who at first only gave his aid exceptionally, has wormed his way in more and more, and was not content until he had modelled vegetative growth after his symbol the egg, and had led us humans all to join the band of his avowed admirers. And he likes to play the mischief with us all individually even now.
In the vertebrate animals, the nervous system, the organs of respiration and especially the circulation of the blood are entirely centralised. Yet man still possesses two fully formed segments which carry extremities, i.e., the pelvic ring with two legs, and the shoulder ring with two arms. The remainder of our vertebrae carry two ribs or at least two lateral processes, but they no longer have extremities.
Let us, therefore, consider as the end-point of development our own skeleton, and firstly the hindermost portion of it. Here as an expression of the telescoping with a forward curve (in harmony with the oval form), it strikes us at once that several vertebrae, which could be distinctly recognised during embryonic life as separate spinal joints, have grown together and shortened in the adult, and form the massive sacrum, while for the rest of the vertebrae nothing remains except a rather useless coccyx, which resembles a rudimentary tail.
Here in the concavity of the embryo as it lay rolled up in the mother-egg, the two reproductive organs developed, and here the newly-formed urogenital system acquired its present form. Afterwards when the pelvis has grown up as a bony framework the mature ovum can safely lie sheltered in the maternal body until it reaches full development.
In contrast to the head, which represents a cavity surrounded by bone, and to the thorax with its bony grating, the frontal wall of the abdomen, as the last wall of the body to be closed, has remained free from ossification. So this is the most suitable spot for adaptation to the bowel contents and for changes of blood pressure, which latter reaches its highest point in the sexual congestion of the blood-vessels. And just because the impulsive variations in blood pressure are the expression of our varied moods, this free play of our blood pressure is of particular importance. In former times when one was of a melancholy and morose disposition, this state was termed hypochondria, because not without reason it was thought that this painful condition was localised beneath the cartilages of the ribs.
On the other hand, the amount of nerve substance in this portion of the body is inferior to that at the upper pole, for in the abdomen there are only a few small scattered collections of nerve centres.
Fortunately we still have nerve centres which are not enclosed, Together these form the sympathetic nervous system, which transmits only vague, but so much the more intimate sensations with-out further localisation, and further intervention of the consciousness. So here the sexual life develops as an indefinable but powerful sensory excitement, that can only be disturbed by the interference of the intellect, an antagonism which is thoroughly characteristic of the sexual passion.
Fortunately the process of the telescoping and bending forward did not go any farther at this lower pole, or the act of parturition would have been rendered impossible; but still it is often so difficult, that some of the finest developed children cannot be brought into the world alive, and many a young mother is sent to an early grave. Thus here the limit of possibility has been reached.
Let us now turn to the other pole of our body.
What an immense contrast we have here to the other pole of the body! Here everything crammed with nerve-substance, and there room for the free play of the circulation.
And this vaulting over of the brain in the vertebrate animals 4 is more striking the higher they mount in the scale; in man, for instance, it is strongly developed that the brain actually protrudes over the features of the face. As a result, man and the anthropoid apes were robbed of their last means of escape: they could no longer save themselves from an imminent danger by swimming, because with their heavy heads their breathing organs sank too deeply beneath the surface. So they began to scramble with all four extremities up trees whenever flight was necessary; and this led to a complete change of attitude and form of body.
With this development of the brain, the limit of possibility of existence is almost reached at this pole also, for what a great number of individuals are drowned every year! And yet with the increase of civilisation and mental effort the high vaulting of the skull has constantly increased, as we shall observe if we compare ourselves with the prognathous type seen in primitive races. Yes indeed, our skull is filled with nerve substance to such an extent that here, in contrast to the other pole, is scarcely any room for the circulation of the blood, so that mental strain soon leads to headache. The difficulty of circulation in this organ causes endless suffering, and the slightest effusion of blood in the brain may lead to an apoplexy from which so many people, especially educated ones, perish.
So we see that at both poles of our body, the evolution described above has almost overstepped the limits of possibility of life, and it is not surprising that we men stand at the terminal point of evolution. Our further evolution lies, therefore, far more in a certain refinement, for which much moderation and self-control are needful. Civilisation, an artificial degree of domestication, now holds the mastery over the crude forces of nature. And instead of developing constantly more highly differentiated organs in our bodies, we are always inventing more highly differentiated tools, machines and implements.
Now that we have reached this high stage of civilisation, it is more than ever necessary that the two guiding motives in our lives should keep each other in equilibrium.
Too great attention to one pole is just as dangerous as too great attention to the other. The hygienic and ethical dangers of sexual excess are generally recognised; but a one-sided mental development causes in addition to the hygienic dangers a pre-dominating ethical danger, the danger of a one-sided intellectualism,(5) and to this the more highly developed individuals are the most subject.
Our brain certainly makes us reasonable and cautious, but we only feel happy when an increased circulation powerfully stimulates the whole metabolism and especially our oxidation, which goes on so actively under the stimulation of the sexual life. The functions of our brain teach us how we can even in the most complicated cases avoid danger and seek favourable conditions; but the sexual life fills us indeed with happiness and delight. And how much more inspiring and successful would many an intellectual work, many a sermon or lecture, many a legal judgment be, if not less cold reason, but warmer feeling were put into it.