This erotic monism proclaims as its indestructible foundation the unity of marriage and love.

The idea of unity gives to the human being the right to arrange his sexual life according to his personal wishes, subject to the condition that he does not consciously injure the unity, and therewith, mediately or immediately, the right, of possible posterity.

Thus, according to Ellen Key, love “will continually become to a greater extent a private affair of human beings, whilst children, on the contrary, will become more and more a vital problem of society.” From this it follows that the two “most debased and socially sanctioned manifestations of sexual subdivision (of dualism), coercive marriage and prostitution, will gradually become impossible, because, after the victory of the idea of unity, they will cease to correspond to human needs.”

Ellen Key rightly insists that among the young men of the present day there is an increasing hostility to socially protected immorality (both in the form of coercive marriage and in that of prostitution); whilst they increasingly exhibit a monistic yearning for love. The general diffusion, which we shall describe at length in a special chapter, of ascetic moods and of misogyny among men and of misandry among women, is partly connected with the feeling that the present social forms of the sexual relationship limit to an equal extent the worth and the freedom of mankind.

To-day the “purity fanatics and the frantic sensualists” meet in common mistrust of the developmental possibilities of love, because they do not believe in the possible ennoblement of the blind natural impulse. In contrast to these, Ellen Key reminds us of the fact of the “mystical yearning for perfection, which in the course of evolution has raised impulse to become passion, and passion to become love, and which is now striving to raise love to an ever greater love.”

We must recognize love as the spiritual force of life. Love, like the artist, like the man of science, has a right to the peculiar, original activity of its own poietic force, to the production of new spiritual values. The more perfect race that is to come must, in the fullest meaning of the words, be brought forth by love.

For this, however, the indispensable preliminary is the inward freedom of love; the free-love union is the watchword of the future. Ellen Key also shows that among the lower classes free love has long been customary, and that there the dangerous utilization of prostitution is far more limited than among the higher classes, with which view Blaschko’s statistical data regarding the far greater diffusion of venereal diseases among the higher classes of society are in substantial agreement.

No less indispensable to free love, however, is the full, mature development of the loving individual. For this reason, Ellen Key demands self-control and sexual continence at least until the age of twenty years. She regards the indiscriminate sexual intercourse which is to-day an established custom among all young men as the murder of love. But too early marriages are no less dangerous. She demands for the woman at least an age of twenty; for the man, an age of twenty-five years; and until these respective ages are attained, sexual continence should be observed as fully as possible by both sexes.

This self-command is good for the physical development, “steels the will, gives the joy of power to the personality; and these qualities are later of importance in all other spheres of activity.”

With wonderful beauty, Ellen Key describes the happiness of the power of waiting in love, and quotes in this connexion the lovely phrases of the Swedish poet Karlfeldt: