Parallel with this development of the brain there has occurred a progressive development of sexuality from the lowest animal instinct to the highest human “love.” The way of the spirit in love becomes predominant pari passu with the development of mankind in civilization. There is a profound meaning in the saying of Schopenhauer that the transformation of the sexual impulse into passionate love represents the victory of the intelligence over the will. And when another writer of genius has described the history of civilization as the history of the progress of mankind from nearer to more remote, more spiritual stimuli of pleasure, this is above all true of human love.
In lower states of human love these spiritual elements are undoubtedly wanting. Amongst primitive men the manifestations of sexuality can have differed in no wise from those of the animals most nearly related to them. Their love was still a pure animal instinct. The Asiatic myth which divided the earliest periods of human history in this way, asserting that the inhabitants of paradise loved for thousands of years merely by means of glances, later by a kiss, by simple physical contact, until ultimately they underwent a “fall” through adopting the debased methods of common animal sexual indulgence—this infantile mythology would be accurate enough if one inverted the series of stages in the evolution of love.
This view is confirmed by the fact that, according to the most recent investigation into the history of primitive man, it is extremely probable that to palæolithic man of the earlier diluvial period the idea of the spiritual was still completely unknown—that palæolithic man was, in fact, purely a creature of impulse—an opinion already maintained by Darwin in his work on the “Descent of Man.” In the sexual instinct, above all, every dualistic division into physical and spiritual was entirely foreign to primitive man. The more primitive the state of civilization, the less is the idea “love” known, a fact first established by Lubbock. Even at the present day, in regard to this matter, there is a notable difference between the upper and the lower classes in a European civilized community. For example, Elard Hugo Meyer, in his excellent “Deutsche Volkskunde” (“German Folk-lore,” p. 152; Strasburg, 1898), states that from Eastern Friesland to the Alps amongst the common people the word “love,” to us so indispensable and so exalted, is entirely unknown; in its place words expressing rather the sensual side of the impulse are employed.
Rousseau suggested that primitive man embraced primitive woman only in the fugitive moments of domination by his instinctive impulse. It is no doubt very probable that primæval man shared with other animals the periodicity of the sexual impulse; this periodicity disappeared only in the subsequent course of human development, and traces of it yet remain. It is probable that this periodicity of the sexual impulse was associated with variations in the supply of nutriment, and was thus, as Darwin assumes, a kind of natural obstacle to too rapid an increase in the population. Later, in consequence of an increase in individual security, and of a more enduring supply of abundant nutriment, such periodic rutting ceased to occur, or was preserved only in the form of menstruation (ovulation) in women, in whom at this period there is a perceptible increase in sexual excitability. Among savage races this periodicity of the sexual impulse, its increase at definite seasons of the year, is still clearly manifested even in the male. Heape and Havelock Ellis have carefully studied this primitive phenomenon, and have adduced numerous proofs of its truth.[5]
Only the human female experiences true “menstruation”; that is to say, only in women is the maturation of the ovum accompanied by a monthly discharge of blood from the genital passage. The so-called menstruation of female apes is limited to a periodic swelling of the external genital organs, with a mucous discharge therefrom. According to Metchnikoff, the menstruation of apes constitutes the intermediate stage between the rutting of the lower animals and the menstruation of the human female. This latter is a new acquisition, the purpose of which is perhaps the limitation of fertility and the prevention of the excessively early marriage of girls.
With the advanced development of the brain, the old periodic rutting, of which rudiments still persist, became more and more subordinate to the conscious will, was transformed more and more into enduring love. Charles Letourneau writes:
“If we go to the root of the matter, we find that human love is in its essence merely the rutting season in a reasoning being; it increases all the vital forces of the human being, just as rutting increases those of the lower animals. If love apparently differs enormously from rutting, this is merely due to the fact that the reproductive impulse, the most primitive of all impulses, becomes in developed nerve centres more diffuse in its sphere of operations, and thus in man awakens and excites a whole province of psychical life which is entirely unknown to the lower animals.”
Philosophers and scientific observers have defined the distinction between human and animal love as consisting in the fact that man can love at all times, the animal periodically only; but this distinction certainly does not apply to the beginnings of human development; it originates beyond question with the first appearance of the spiritual element in love. This alone makes man capable of enduring love, this alone frees him from dependence upon periodic rutting seasons. The prolongation of love by the introduction of the spiritual element was already pointed out by Kant, whose writings (especially the lesser ones) are rich in valuable observations of a similar kind. In his treatise published in 1786, “The Probable Beginning of Human History,” he says regarding the sexual instinct:
“Reason, as soon as it had become active, did not delay to exert its influence also in the sexual sphere. Man soon discovered that the stimulus of sex, which in animals depended merely on a transient and for the most part periodic impulse, was in his own case capable of prolongation, and indeed of increase, by the force of imagination. This influence works more moderately, it is true, but with more persistence and more evenness the more the affair is withdrawn from the dominion of the senses, so that the satiety produced by the gratification of a purely animal passion is avoided.”
This important question regarding the origin of the love of human beings as contrasted with the periodic instinct of the lower animals and primitive man has hitherto, strangely enough, hardly received any attention, notwithstanding the fact that it is one of the most important evolutionary problems in the history of human civilization, and represents to a certain extent the only problem in the primitive history of love.